Secondary Unit Substations
advertisement
Secondary Unit Substations Guide Form Specifications 6 Secondary Unit Substations A unit substation is defined as a substation consisting of one or more transformers mechanically and electrically connected to and coordinated in design with one or more switchgear or switchboard assemblies. A secondary unit substation is defined as a unit substation whose outgoing section is rated below 1000 volts. A typical secondary unit substation consists of three sections: 1. An incoming section that accepts incoming high voltage (2400 to 13,800 volts) line. 2. A transformer section that transforms incoming voltage down to utilization voltage (208/120 to 600 volts). 3. An outgoing section that distributes power to outgoing feeders and provides protection for these feeders (600 volts and less). The primary reason for using a secondary unit substation is to bring power as close as possible to the center of the loads. Another reason is that it provides a system design concept incorporating a wide variety of components that permits tailoring equipment to the needs of the application. A secondary unit substation provides 쐍 Reduced power losses 쐍 Better voltage regulation 쐍 Improved service continuity 쐍 Increased functional flexibility 쐍 Lower installation cost 쐍 Efficient space utilization Every component and assembly of secondary unit substations are designed and engineered as an integral part of a complete system. General Liquid Filled Transformer Primary Switch Type RCIII Switchboard with Bolted Pressure Switches Dry Type Transformer Primary Switch Liquid Filled Transformer Primary Switch CSI Section 16470 Type RCIII Switchboard with SB Encased Systems Breakers Siemens Electrical Products and Systems Specification Guide Type R Low Voltage Switchgear 75 Secondary Unit Substations Guide Form Specifications 6 Secondary Unit Substations A unit substation is defined as a substation consisting of one or more transformers mechanically and electrically connected to and coordinated in design with one or more switchgear or switchboard assemblies. A secondary unit substation is defined as a unit substation whose outgoing section is rated below 1000 volts. A typical secondary unit substation consists of three sections: 1. An incoming section that accepts incoming high voltage (2400 to 13,800 volts) line. 2. A transformer section that transforms incoming voltage down to utilization voltage (208/120 to 600 volts). 3. An outgoing section that distributes power to outgoing feeders and provides protection for these feeders (600 volts and less). The primary reason for using a secondary unit substation is to bring power as close as possible to the center of the loads. Another reason is that it provides a system design concept incorporating a wide variety of components that permits tailoring equipment to the needs of the application. A secondary unit substation provides 쐍 Reduced power losses 쐍 Better voltage regulation 쐍 Improved service continuity 쐍 Increased functional flexibility 쐍 Lower installation cost 쐍 Efficient space utilization Every component and assembly of secondary unit substations are designed and engineered as an integral part of a complete system. General Liquid Filled Transformer Primary Switch Type RCIII Switchboard with Bolted Pressure Switches Dry Type Transformer Primary Switch Liquid Filled Transformer Primary Switch CSI Section 16470 Type RCIII Switchboard with SB Encased Systems Breakers Siemens Electrical Products and Systems Specification Guide Type R Low Voltage Switchgear 75 Secondary Unit Substations Incoming Line Section Secondary Unit Substations 6 General The incoming line section of a Siemens secondary unit substation can be ordered in any one of four basic configurations. The most commonly used is the air interrupter switch providing a primary disconnect. When primary circuit protection and / or disconnection means is located near the substation, an air terminal chamber is the usual choice. A liquid interrupter switch and an oil cutout switch are two alternatives. A primary metering unit can also be incorporated in the incoming line section. Air Interrupter Switch The Siemens air interrupter switch is a stationary mounted, three pole, two position (open-close) device which uses a quick-make, quick-break arcing blade with an arc chute for safe closing and normal current interruptions. The switch position is visible through a safety front window and is indicated on the operating handle mechanism. The switch sections are available in UL listed or non UL listed applications. The switch is available with or without fuses, which can be either current limiting or expulsion type. Each fused switch has a hinged compartment door that covers the fuses and is mechanically interlocked with the switch so the door can be opened only when the switch is open. The switch is available with cable lugs or potheads and can be arranged for top or bottom entrance of cables. Surge arresters can be furnished, if required. A duplex switch is also available, consisting of two Key interlocked switches located side by side. This arrangement permits the selection of one of the two incoming sources of power to the transformer. The air interrupter selector switch consists of a stationary rear-mounted, three pole, two position (Line I-Line 2) switch in series with a three pole, two position (ON-OFF) interrupter switch. Mechanical interlocking is provided so that the load interrupter switch must be open before the selector switch can be changed from one feeder to another feeder. See Table 6.1 for available switch ratings. Air Terminal Chamber The air terminal chamber is floor mounted and can be equipped with cable lugs or potheads (optional). It is directly connected to the high voltage side of the transformer. Both indoor and outdoor construction is available, and the unit can be arranged for top or bottom entrance. Space can be provided for loop feeding of cables, if needed. 76 Single Air Interrupter Switch / Dry Type Transformer Since air terminal chambers provide no means either to disconnect or to protect the transformer, such a means should be provided upstream from the transformer. Liquid Interrupter Switch This is a three pole, two or three position non-fused assembly with the switch immersed in oil. It can interrupt load currents up to 400 amperes. The liquid interrupter switch is available only on substations incorporating a liquid filled transformer. Primary Metering Unit This is a separate unit available to match an adjacent air interrupter switch unit. It can be equipped with current transformers, potential transformers and devices for user metering or with complete provisions for power company metering. Special designs can be provided to meet local power company requirements. Single Air Interrupter Switch with Fuses Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Incoming Line Section Table 6.1 6 Indoor Air Interrupter Switch Ratings Voltage Ratings 햲 햳 Current Ratings 4.16 4.76 19 7.2 8.25 26 13.8 15.00 36 햲 햳 Short-Time Ratings 1.2 x 50 Load Impulse Continuous Interrupt Momentary Withstand Ampere Amperes Assym. 2-Sec kV, BIL RMS RMS kA, RMS kA, RMS 600 600 40 25 60 1200 1200 61 38 600 600 40 25 75 1200 1200 61 38 600 600 40 25 95 1200 1200 61 38 Secondary Unit Substations 1 Min. Power Maximum Frequency Nominal Design Withstand kV, RMS kV, RMS kV, RMS 햲 햳 Technical FaultClose kA, RMS Assym. 40 61 40 61 40 61 Ratings apply to Stored Energy Operated Switches. Special ratings available — consult Siemens. UL and MET listings for specific application — consult Siemens. Table 6.2 Max Design kV Power Fuses System kV Interrupting Ratings RMS Symmetrical Nom. Equiv. Amperes 3ø -MVA햲 Maximum Continuous Ratings Single Barrel Double Barrel Triple Barrel 200E 200E 200E 125E 125E 125E 125E 125E 125E 125E 125E 400E 400E 400E 250E 250E 250E 250E 250E 250E 250E 250E — — — — — — — — — — — — — — — 600E 750E — — — — — — — — Current Limiting Fuse 5.5 15.5 5.5 15.5 2.4 4.16 4.8 6.9 7.2 11.5 12.0 12.47 13.2 13.8 14.4 2.4 4.16 4.8 4.8 4.8 4.8 6.9 7.2 11.5 12.0 12.47 13.2 13.8 14.4 50,000 50,000 50,000 40,000 40,000 40,000 40,000 40,000 40,000 40,000 40,000 60,000 60,000 60,000 60,000 50,000 50,000 50,000 50,000 40,000 40,000 40,000 40,000 40,000 40,000 208 360 416 480 500 800 830 860 910 955 1000 250 430 500 500 500 500 596 620 800 830 860 910 955 1000 10E through 150E — — — 10E through 100E 175E through 450E — — — — 125E through 200E Duplex Air Interrupter Switch Expulsion Fuse — S & C Type SM or Westinghouse Type RBA 5.5 17 15.5 햲 햳 4.8 4.8 14.4 14.4 14.4 13.8 17,200 37,500 14,000 12,500 25,000 34,000 125 270 335 300 600 815 200E 400E 200E 200E 400E 400E — 720E햳 — — — — — — — — — — The 3ph MVA = 1.73 x (kv) x (fuse interrupting kA) Double Barrel Fuse. Consult Siemens for dimensions. CSI Section 16470 Siemens Electrical Products and Systems Specification Guide 77 Secondary Unit Substations Incoming Line Section 6 Table 6.3 Current-Limiting Fuse Selection햲 Secondary Unit Substations Transformer Rating kVA햳 150 225 300 500 750 1000 1000 1500 2000 2500 3000 Impd. %햴 2.0-4.5 3.5-4.5 4.0-5.0 5.0 5.75 8.0 5.75 5.75 5.75 5.75 5.75 Transformer Rating kVA햳 150 225 300 500 750 1000 1000 1500 2000 2500 3000 Impd. %햴 2.0-4.5 3.5-4.5 4.0-5.0 5.0 5.75 8.0 5.75 5.75 5.75 5.75 5.75 Transformer Rating kVA햳 150 225 300 500 750 1000 1000 1500 2000 2500 3000 Technical Impd. %햴 2.0-4.5 3.5-4.5 4.0-5.0 5.0 5.75 8.0 5.75 5.75 5.75 5.75 5.75 2.4 System kV, Line-to-Line Fuse Size FLA Min 133% 36 40E 50E 54 65E 80E 72 80E 100E 120 150E 200E 180 200E 250E 241 300E –– 241 300E 400E 361 400E 500E 482 600E –– 602 — — 722 — — 7.2 System kV, Line-to-Line Fuse Size FLA Min 133% 12 15E 20E 18 20E 25E 24 30E 40E 40 50E 65E 60 80E 80E 80 100E –– 80 100E 125E 120 150E 200E 160 200E 200E 201 — — 241 — — 13.2 System kV, Line-to-Line Fuse Size FLA Min 133% 6.6 10E 10E 9.8 15E 15E 13 15E 20E 22 25E 30E 33 40E 50E 44 50E 65E 44 50E 65E 66 80E 100E 88 100E 125E 109 125E 150E 131 150E 200E Max 80E 100E 125E 200E 300E 300E 400E –– –– — — 4.16 System kV, Line-to-Line Fuse Size FLA Min 133% 25E 30E 21 40E 40E 31 50E 65E 42 80E 100E 69 125E 150E 104 200E 200E 139 200E 200E 139 250E 300E 208 400E 400E 278 400E –– 348 450E 600E 416 Max 25E 40E 50E 80E 100E 100E 150E 200E 200E — — 11.5 System kV, Line-to-Line Fuse Size FLA Min 133% 10E 10E 7.5 15E 15E 11.3 20E 20E 15.1 30E 40E 25.1 50E 50E 37.7 65E 80E 50.3 65E 80E 50.3 100E 100E 75.4 125E 150E 101 125E 200E 126 200E 200E 151 Max 15E 20E 30E 50E 65E 65E 80E 100E 150E 150E 200E 13.8 System kV, Line-to-Line Fuse Size FLA Min 133% 10E 10E 6.2 15E 15E 9.4 15E 15E 12.6 25E 30E 21 40E 50E 32 50E 65E 42 50E 65E 42 80E 100E 63 100E 125E 84 125E 150E 105 200E 200E 125 Max 40E 65E 80E 125E 150E 200E 250E 400E 400E –– –– 4.8 System kV, Line-to-Line Fuse Size FLA Min 133% 25E 25E 18 30E 40E 27 40E 50E 36 65E 80E 60 100E 125E 90 150E –– 120 150E 200E 120 200E 250E 180 300E 400E 241 400E 400E 300 400E –– 362 Max 40E 50E 80WE 100E 150E 150E 200E 300E 400E 400E –– 6.9 System kV, Line-to-Line Fuse Size FLA Min 133% 12 15E 20E 19 25E 25E 25 30E 40E 42 50E 65E 63 80E 100E 84 100E –– 84 100E 125E 126 150E 200E 167 200E –– 209 –– –– 251 –– –– Max 25E 40E 50E 80E 100E 100E 150E 200E 200E –– –– Max 15E 25E 30E 50E 80E 80E 100E 125E 150E 200E 200E 12.0 System kV, Line-to-Line Fuse Size FLA Min 133% 10E 10E 7 15E 15E 10.8 20E 20E 14.4 30E 40E 24 40E 50E 36 65E 65E 48 65E 65E 48 80E 100E 72 125E 150E 96 150E 200E 120 200E 200E 144 12.47 System kV, Line-to-Line Fuse Size FLA Min 133% 7 10E 10E 10.4 15E 15E 14 15E 20E 23 25E 30E 35 40E 50E 46 50E 65E 46 50E 65E 70 80E 100E 92 100E 125E 116 150E 200E 139 150E 200E Max 15E 20E 30E 50E 80E 80E 100E 125E 150E 200E 200E Max 15E 20E 30E 50E 65E 65E 80E 125E 150E 200E 200E Max 15E 20E 25E 30E 65E 65E 80E 100E 150E 150E 200E 14.4 System kV, Line-to-Line Fuse Size FLA Min 133% 10E 10E 6 15E 15E 9 15E 20E 12 25E 30E 20 40E 40E 30 50E 65E 40 50E 65E 40 65E 80E 60 100E 125E 80 125E 150E 100 200E 200E 120 Max 10E 20E 25E 40E 65E 65E 80E 100E 150E 150E 200E 햲 Minimum fuse size shown will clear transformer magnetizing inrush current. 133% fuse size permits overload operation of transformer up to 133% rating. Maximum fuse size provides transformer fault protection for phase-phase, 3-phase and phase-ground faults on secondary windings of standard 3-phase transformers. Suffix E denotes NEMA standard fuse rated 30˚C rise above 40˚C average ambient. 햳 The self-cooled kVA rating of the transformer as listed here should be used in selection of fuse size on forced-air cooled transformer applications. Also, on such applications, the 133% fuse size must be chosen for proper coordination. 햴 Typical percent impedance on self-cooled kVA base, subject to + 71/2% tolerance. _ 78 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Incoming Line Section General 6 D Front Access D Rear Access Secondary Unit Substations 3 LA’s optional 3 LA’s optional H H W W Single Switch Single Switch Top entry with optional distribution class lightning arrestors Top or bottom entry optional distribution, station, or intermediate class lightning arrestors 햵 D D H H W W Non UL version W UL version Selector Switch Duplex Switch Front access standard optional rear access 5 kV and 15 kV Primary Switch, Indoor, UL and non UL versions Table 6.4 Primary Switch Dimensions — Manually Operated Switches햳 Voltage Class Rating Switch Arrangement — Fused and Non-Fused Dimensions in Inches (mm) H W D Front Access 햴 D Rear Access 햵 Weight Lb. (kg) 햲 햳 햴 햵 Single Switch UL Non UL 90.00 93.13 (2286) (2366) 30.00 36.00 (762) (914) 48.00 44.00 (1219) (1118) 58.00 60.00 (1473) (1524) 1000 1200 (454) (544) 5 kV Duplex Switch UL Non UL 90.00 93.13 (2286) (2366) 60.00 88.00 (1524) (2235) 48.00 44.00 (1219) (1118) 58.00 60.00 (1473) (1524) 2000 2700 (907) (1225) Selector Switch UL Non UL 90.00 햲 (2286) 38.00 햲 (965) 햲 햲 — N/A 88.00 (2235) 1600 (726) Single Switch UL Non UL 90.00 93.13 (2286) (2366) 36.00 36.00 (914) (914) 58.00 44.00 (1473) (1118) 58.00 60.00 (1473) (1524) 1000 1200 (454) (544) 15 kV Duplex Switch UL Non UL 90.00 93.13 (2286) (2366) 72.00 88.00 (1829) (2235) 58.00 44.00 (1473) (1118) 58.00 60.00 (1473) (1524) 2000 2700 (907) (1225) Selector Switch UL Non UL 90.00 햲 (2286) 38.00 햲 (965) 햲 햲 — N/A 88.00 (2235) 1600 (726) UL Listed Selector Switch not available. Conduit areas not shown. Conduit locations vary widely based on section configuration. Consult Siemens for conduit locations and dimensions. Front access for top entry only. Rear access required for bottom entry and / or Station Class or Intermediate Class Lightning Arrestors. Note: Dimensions for estimating purposes only, not for construction. CSI Section 16470 Siemens Electrical Products and Systems Specification Guide 79 Secondary Unit Substations Transformer Section Secondary Unit Substations 6 Siemens secondary unit substations are available with a choice of liquid filled or dry type transformers. Liquid filled units are available with either oil, R-Temp, or silicone as the insulating fluid. Dry type units can be conventional or cast coil. Table 6.5 lists the standard transformer ratings for each type. Non-standard units are also available with such characteristics as special temperature rises, insulation levels, low losses, low noise levels, special impedances, and voltages to meet specific application requirements. Weights, dimensions, and performance characteristics of non-standard units can be obtained from Siemens. Many factors are involved in the choice of a transformer for a particular application. These range from initial cost to environmental factors to personal preference. Liquid filled transformers have their core and coil immersed in either mineral oil, R-Temp, or silicone fluid. The oil-filled transformer is generally applied outdoors but may also be applied indoors when designed to avoid any possible fire hazard. Oil-filled units are the lowest cost of all the available types of transformers and feature compact size and high BIL levels. R-Temp and silicone filled General transformers are similar to the oil-filled type in construction and features with the exception of the insulating fluid. These units are designed primarily for indoor application but can also be used outdoors near building walls or on roofs. R-Temp fluid has a fire-point of 311°C. Silicone offers a fire-point of 371°C. A ventilated dry type transformer is one in which the windings are cooled by the natural circulation of ambient air through the transformer. This type transformer utilizes vacuum pressure impregnation (VPI), a superior moisture-resistant insulation system designed to operate at an average temperature rise of 150°C. VPl / epoxy dry types are applied in areas where heavy or conducting contaminants exist in the air. Ventilated dry type transformers are lightweight and are fire and toxic resistant. Outdoor dry type transformers have been developed for situations which prohibit indoor installation yet still require a nonflammable transformer. The weather resistant ventilated unit is protected from the elements. A special offset double wall louver system is designed to divert blowing rain and snow, and to channel it out through the bottom of the enclosure. Where severely contaminated conditions do not exist, the weather resistant ventilated transformer can offer lower operating costs while providing adequate service life and performance. Outdoor transformers have gasketed panels and roofs. Enclosure roofs are slanted so that rain and melting snow cannot interfere with operation. An overhang on all four sides provides extra weather protection. The cast coil transformer has its high voltage coils vacuum cast in epoxy resin providing a non-hygroscopic, sealed coil, highly resistant to moisture and industrial and chemical contaminations. It has excellent dynamic short circuit strength. The cast coil insulation provides small size, low sound levels, and high efficiency. It is virtually non flammable and self extinguishing. It has unlimited storage duration and will be ready for immediate use. Siemens unit substation transformers liquid filled, dry type, and cast coil can be custom designed to meet customer specifications including loss evaluations, harmonic load conditions, or other special applications. Table 6.5 Standard Transformer Ratings Transformer Type 햲 햳 햴 Primary Voltages Liquid Filled 65°C Rise햳 See page 81 2400 4160 4800 6900 7200 12000 12470 13200 13800 VPI Ventilated Dry Type 150° C Rise햳 VPI/Epoxy Dry Type 115°C Rise See page 84 2400 4160 4800 6900 7200 12000 12470 13200 13800 Cast Coil Dry Type 80 or 115°C Rise햳 See page 87 2400 4160 4800 6900 7200 12000 12470 13200 13800 kVA 3-Phase SelfCooled 150 225 300 500 750 1000 1000 1500 2000 2500 3000 150 225 300 500 750 1000 1000 1500 2000 2500 3000 150 225 300 500 750 1000 1000 1500 2000 2500 3000 kVA 3-Phase FanCooled — — — — 862 1150 1150 1725 2300 3125 3750 — — 400 667 1000 1333 1333 2000 2666 3333 4000 — — 400 667 1000 1333 1333 2000 2666 3333 4000 Secondary Voltage 208Y / 120V or 480Y / 277V or 240 Delta 480V Delta ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — ✓ — ✓ — ✓ — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — ✓ — ✓ — ✓ — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — ✓ — ✓ — ✓ — Std. Impedance햲 (% IZ) 2.0-4.5햴 3.5-4.5햴 4.0-5.0햴 4.0-5.0햴 5.75 5.75 8.0 5.75 5.75 5.75 5.75 5.0 5.0 5.0 5.75 5.75 5.75 8.0 (opt.) 5.75 5.75 5.75 5.75 3.0 4.0 5.0 5.75 5.75 5.75 8.0 (opt.) 5.75 5.75 5.75 5.75 NEMA Sound Level (dB) SelfForced-Air Cooled Cooled 55 — 67 55 67 55 67 56 67 57 67 58 67 58 67 60 67 61 67 62 67 63 — 55 — 58 — 58 — 60 67 64 67 64 67 64 67 65 67 66 67 68 67 70 — 55 — 58 — 58 67 60 67 64 67 64 67 64 68 65 69 66 71 68 71 70 Standard impedance tolerance is ±7 1/2%. Impedance values apply to units with standard BIL ratings. Higher BIL ratings are typically 1% to 1.5% higher impedance. For applications where the average ambient temperature is 30°C. Transformers with impedances of 4.0% or less are designed to withstand 25 times normal current for two seconds. 80 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transformer Section — Liquid Filled 6 Secondary Unit Substations Core Construction Wound cores of Siemens liquid filled transformers are rectangularly shaped, single turn laminations of high quality, grain oriented magnetic core steel. Fully annealed after cutting and forming, the core loops can be opened for assembly through coil windows without deterioration in performance characteristics. Lamination joints are staggered and precisely cut for close fit. Each loop rests on the joint end, and is in direct contact with the bottom core clamp for positive grounding. Cores are compact and designed for low excitation currents, low losses and quiet performance. The upper and lower core clamps are rigidly constructed. Core clamps are chemically cleaned to remove any dirt or impurities from the forming and welding operations. This assures that only clean metal will be in contact with the cooling medium. Core clamps and all structural parts are insulated from live parts to prevent development of voltage potential in any part. General Low Voltage Throat with full length air terminal chamber (Optional) High Voltage Throat (Optional) Coil Construction The coil is of rectangular construction with sheet-wound aluminum secondary windings and insulated wire-wound aluminum primary windings (copper windings available as an option). Coils are equipped with cooling ducts in order to dissipate the heat being generated. Sufficient ducts are located throughout the coils to avoid winding hot spots to assure overload capability. Stresses Axial short circuit stresses are virtually eliminated by the use of sheet-wound secondary and wire-wound primary windings with no interleaved components. Coils are wound with the secondary coil nearest the core and supported by a strong insulating form. The primary is wound directly over the secondary coil with a suitable insulating full-length barrier between the primary and secondary windings. The coil wire is wound tightly and uniformly through a tension device. Conductors are bonded to a diamond patterned epoxy paper to insure maximum short circuit strength. Insulating Material All insulating materials have been thoroughly tested and proven with respect to their electrical and mechanical characteristics and are stable at nameplate operating temperatures. In liquid filled transformers, the insulation system is thermally upgraded and CSI Section 16470 Low Voltage Throat (Optional) Accessories and Control Cabinet chemically modified to resist the effects of high temperature. This enables the transformer to maintain full load-carrying ability at rated operating temperature without affecting life expectancy. Thermally-upgraded corrugate or stick duct insulation is used for longitudinal and radial coil spacers. It is also used between layers, and between high and low voltage coils. The porosity of the insulating materials permits the insulating liquid to penetrate the insulating material, giving it a high dielectric strength. Tap Changer The externally operated tap changer allows for line voltage changes, when de-energized. The stacked multi-phase assembly features one-piece stationary contacts rigidly locked in place. All three phases are switched simultaneously on the stacked multi-phase rotary switch. Switching of the contacts is made through a bridging roller. Siemens Electrical Products and Systems Specification Guide 81 Secondary Unit Substations Transformer Section — Liquid Filled General Secondary Unit Substations 6 햲 Radiators Provided as required to meet rating specifications. Detachable radiators optional. 햳 Low Voltage Bushing Terminals 햴 Primary and / or Secondary Throat (optional) 햵 Cover Lifting Eyes (optional) 햶 Inspection Port Handhole Bolted, sealed cover allows interior inspection. 햷 Pressure Relief Device Automatic resealing device (optional). Available with optional alarm contacts. 햸 Sudden Pressure Relay (optional) 햹 Top Filter Press Connection and Fill Pipe 햺 Pressure / Vacuum Gauge Available with optional alarm contacts. 햻 Tank Lifting Lugs Lift hooks welded to tank at each corner 햽 Liquid Level Gauge Shown with optional alarm contacts. 82 햾 Temperature Gauge Provided with magnetic resettable pointer. Shown with optional alarm contacts. Indicates top fluid temperature. 햿 Tap Changer De-energized, externally operable, handle equipped for locking. 헀 Control Cabinet (optional) 헁 Nameplate 헂 Primary and / or Secondary Full Height Flange (optional) 헃 Grounding Pad Front and rear. 헄 Fluid Drain Sampling Valve One-inch drain valve with sampler. 헅 Base Suitable for skidding or rolling. 헆 Jacking Pads Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transformer Section — Liquid Filled 240 volts, single phase. Operating voltage and wiring to control cabinet must be supplied by customer. Fan blades utilize low noise design that is maintenance free, and fan guard design meets OSHA requirements. Optional 55°C / 65°C rise rating provide a 12% increase in kVA capacity when operated at 65°C rise over ambient. Standard Accessories 쐍 De-energized tap changer, externally operated 쐍 Combination drain and filtering valve with sampling device 쐍 Pressure test connection 쐍 1-in. (25 mm) upper filling and filter press connection 쐍 Thermometer (dial type) 쐍 Provision for lifting and jacking 쐍 Ground pads, front and rear 쐍 Nameplate with diagram and rating 쐍 Pressure vacuum gauge 쐍 Pressure relief valve 쐍 Liquid level gauge Table 6.6 Special Fluids R-Temp and Silicone fluids are fire resistant liquid dielectric coolants formulated for use in transformers installed indoors, on roofs, in close proximity to buildings and structures, and significant public access areas. Their unique electrical, thermal, and safety properties are advantageous to these applications where transformer rupture, explosion, or fire would be most undesirable. R-Temp fluid is a high molecular weight, paraffinic hydrocarbon-based material with a fire-point of 312°C. Silicone fluid has a fire point rating of 371°C. Forced-Air Cooling OA / FA Ratings — Standard Siemens secondary unit substation transformers are OA (self-cooled) rated. Installation of optional forced-air cooling equipment (available on 750 kVA and above equipment) changes the rating to OA / FA (self-cooled / forced air) and increases kVA capacity by 15% (750-2000 kVA) and 25% (2500 kVA and above). Cooling Equipment — Controls are temperature activated from contacts on liquid temperature gauge. Manual override is provided. Fan motors are 120 or CSI Section 16470 Typical Fluid Information햲 Typical Fluid Properties햳 Chemical Name Structure Dielectric Dielectric Strength (ASTM D 877) 25°C KV Thermal Physical Optional Accessories 쐍 Pressure relief device 쐍 Rapid rise relay 쐍 Winding temperature indication and relay (indicate hot spot or other) 쐍 Lightning arresters (distribution, intermediate or station class) 쐍 Throats (high and / or low voltage) 쐍 Air terminal cabinets (high and / or low voltage) 쐍 Detachable bolt-on radiators with valves 쐍 Pressure / vacuum bleeder valve 쐍 Alarm contacts Mineral Oil Paraffinic Hydrocarbon R-Temp Refined Paraffinic Hydrocarbon Silicon (561 Fluid) Polydimethylsiloxane CxHy CnHm [(CH2)2SiO]y(CH3)2 30 25 35 2.2 2.2 2.7 0.0004 0.009 0.0001 0.004 0.0001 0.0015 1.0 x 1012 -40 1.0 x 1013 -15 1.0 x 1014 -50 Dielectric Constant (ASTM D 924) 25°C Dissipation Factor (ASTM D 924) 25°C (ASTM D 924) 100°C Volume Resistivity (ASTM D 1169) ohm cm 25°C Pour Point (ASTM D 97) °C Thermal Conductivity (ASTM D 2717) Cal / (sec cm2 °C)/cm Specific Heat (ASTM D 2766) Cal / gm / °C 25°C 0.00029 0.00030 0.00036 0.393 0.450 0.360 Coefficient of Expansion (ASTM D 1903) (OC / OC / °C) 0.00076 0.00080 0.00104 0.869-0.910 0.957-0.964 40 20.8 350-379 120-140 238 311 47.5-52.5 35-39 268 371 546 361 H2, CO, H2O, CO2, CHn 53 25 H2, H2O, CO, CO2, CHn Specific Gravity (ASTM D 1298) 25°C 0.875-0.910 Interfacial Tension (ASTM 0971) (dyne/cm) 25°C 40 Viscosity (ASTM D 445, D 2161) 25°C 14-16 40°C 12.0 Flash Point (ASTM D 92) °C 150 Fire Point (ASTM D 92) °C 160 Rate of Heat Release at 60 Kw / m2 2 Convective, Kw / m 906 Radiative, Kw / m2 661 Main Gases Evolved During H2, CO, H2O, CO2, CHn Combustion 햲 From Dow Corning bulletin 561 Transformer Fluid, Bulletin 10-278D-93, 1993. 햳 See Standard Specifications for Silicone Fluid Used for Electrical Insulation, ASTM Siemens Electrical Products and Systems Specification Guide D 4652-87, March 1987. 545-546. 83 6 Secondary Unit Substations Tank Construction The transformer tank is fabricated of precision cut, heavy gauge, cold rolled steel plates with a minimum number of plates used to reduce the number of welded seams. Formed structural members are welded to the side wall so the complete tank is sufficiently reinforced to withstand a test pressure 25% greater than normal operating pressure. The top of the tank is fully strengthened with welded plate steel. Lifting devices are provided at the corners of the tank to permit crane handling of the transformer. Cooling radiators assure that the temperature rise of the liquid will not exceed the specified limit when the transformer is continuously operated at full load. The entire tank is shot blasted and then steam cleaned before painting to remove any impurities from the forming and welding operation. Each tank is painted with alkyd enamel paint in accordance with ANSI standards. A flange is provided on the primary and secondary sides of the transformer for bolting to the incoming and outgoing sections, providing an uninterrupted lineup of equipment. General Secondary Unit Substations Transformer Section — Dry Type Secondary Unit Substations 6 Core Construction The core construction of each Siemens ventilated dry type transformer is made of non-aging, high permeability, grain oriented, cold rolled, silicon steel specifically processed for low losses. The thingauge laminations are precision cut with special high quality shear blades in such a manner that the flux path is aligned with the axis of highest permeability in the steel. Each lamination is flat and free from burrs and is inorganically insulated on both surfaces to minimize eddy-current losses. Laminations are stacked to computer specifications on a specially designed table to ensure flatness and prevent the introduction of bending stresses while the finished core is being set in an upright position. Careful positioning of each lamination produces close fitting joints to minimize core loss and noise. As an optional feature, custom miter cut joints can be supplied for premium quality, low core loss design, or where required by customer specification. Cores are designed to accommodate the coils with the optimum combination of high space factor and air flow, assuring a maximum utilization factor and compact design. The completed core assembly is rigidly clamped using formed steel members ensuring positive support and high strength, and preventing displacement under stress. LV Bus Bar — Top Mounted LV Bus Bar — End Mounted General Ventilated Dry Type Complete Transformer Assembly Coil Construction Coils are precision wound with high quality electrical grade aluminum, or with optional copper conductor. Primary coil construction may be random, layer, or disc, depending on the voltage class and basic impulse level required. Standard construction used is sheetwound aluminum secondary windings and insulated, wirewound primary windings. All coils are braced for full short circuit withstand capability in accordance with ANSI standards. Where sheet windings are employed, axial short-circuit stresses are virtually eliminated. The primary is wound directly on the low-voltage winding with a suitable insulating barrier between the coils consisting of cooling duct spacers and sheet installation built up to the proper thickness. Where the coils are wire-wound, adequate bracing is supplied at the end of the coils to assure full short-circuit capability. Primary coils may also be of the disc or random-type construction with suitable spacers to provide coil-to-coil cooling and insulation. Cooling is achieved by ducts in both the primary and secondary coils. When forced-air cooling is required, the air is directed through the cooling ducts to achieve the forced-air rating. Core and Coil of Ventilated Dry Type Transformer High Voltage Taps 84 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transformer Section — Dry Type General 6 Vacuum Pressure Impregnation Siemens offers vacuum pressure impregnation (VPI) as a standard feature for dry type transformer construction. The VPI transformer provides high dielectric strength, superior mechanical stamina, and maximum design flexibility. The VPI transformer utilizes high-performance, precatalized, polyester insulating varnish. The varnish creates a clear, yet high-bond strength product. This process completely seals and binds the windings into a high strength, environmentally protected assembly. The VPI process begins with pre-baking the coil assembly to remove any moisture. The assembly is then placed in a vacuum chamber, and the polyester varnish is introduced into the chamber. After the varnish penetrates the assembly, a high pressure blanket of dry nitrogen is placed on top of the varnish forcing the liquid material into every conceivable space and gap. The pressure is broken and the varnish is evacuated. The assembly is then baked to cure and set the insulated materials. VPI / Epoxy Coating (Optional) For environments polluted with chlorides, acids, alkalies, salt water, or high humidity, Siemens offers the epoxy-coated transformer. In addition to the VPI process, two mils of modified epoxy resin is added resulting in a premium transformer that will handle aggressive environments. Secondary Unit Substations Insulating Material All insulating materials have been thoroughly tested and proven with respect to their electrical or mechanical characteristics, are stable at operating temperatures, and are compatible with the cooling medium. All insulating material in the core and coil is chosen for the temperature system of the transformer and capability for that point of application. Random Wound Coil Disc Wound Coil Dry type transformers utilize a UL recognized, 220°C insulation system that incorporates inorganic materials and polyester resins. Principle components of this system include DuPont Nomex® paper, resinglass laminates, silicon rubber, and polyester varnish. K-Factor Ratings (Optional) Siemens dry type unit substation transformers are available with K-Factor rated designs as an optional feature for applications having non-linear or nonsinusoidal load conditions. The transformer K-Factor rating is based on the amount of harmonic distortion indicated in IEEE C57.110. Ratings include: 쐍 K4 for 50% non-linear load 쐍 K13 for 100% non-linear load 쐍 K20 for 150% non-linear load 쐍 K30 for 200% non-linear load 쐍 Other K-Factor rating or harmonic load profile specified. Sheet Wound Coil Layer Wound Coil UL Listed Designs Siemens offers UL listed / UL labeled ventilated dry type transformers. UL listed ratings include 500 through 3000kVA, 5kV and 15kV class primary, 600 volt class secondary, with temperatures rise options of 150°C, 115°C, or 80°C. CSI Section 16470 Siemens Electrical Products and Systems Specification Guide 85 Secondary Unit Substations Transformer Section — Dry Type Secondary Unit Substations 6 Taps All Siemens ventilated dry type transformers include primary windings equipped with voltage adjustment tap leads to compensate for variations in incoming line voltages. Taps are two 2.5% taps full capacity above nominal (FCAN) and two taps full capacity below nominal (FCBN). Tap connections are located on the surface of each coil and are accessible behind removable enclosure panels. Taps are applied while the transformer is deenergized by changing terminal board links or flexible cables to provide for system voltage adjustment. Forced Air Cooling Ventilated, dry type transformers 500 kVA and above are equipped with provisions for future installation of forced air cooling fans. This includes space and mounting provisions for installation of fans and controls. Optional: Complete forced air cooling is available to increase base kVA rating to an additional 33.3% over the self-cooled kVA rating. Complete forced air cooling incorporates the following features: 쐍 Fan motors (120V AC, 1–phase) and blades with personal protective guards. 쐍 Solid state digital temperature indicator that monitors the winding temperature from single phase sensing. Three phase temperature sensing can be specified as an option. 쐍 Control panel with protective fuses and all necessary controls for operation of fan system. 쐍 Auxiliary remote alarm and remote trip contacts. 쐍 All hardware and wiring. 쐍 Self test and memory. General with the same ratings, features, and flexibility of indoor units. The weather resistant feature includes special air louvers and gasketed covers. Although the enclosure is similar to the standard ventilated dry unit, it can be built with tamper resistant construction as an optional feature allowing access only with proper tools. Loss Evaluated Transformers (Optional) Siemens offers transformers with guaranteed losses for customer loss evaluations. A “low loss” design is offered when users are looking for a transformer that, over a period of time, will actually cost less in total owner cost than a standard transformer with higher losses. The cost of electric power has increased over the years. In the past when electricity was less expensive, the first cost, or original purchase price, was the primary con-sideration. With low loss energyconserving transformers, the initial purchase price may be higher because material content is more expensive. However, the payback and continued savings may justify that cost in operating expenses when an optimized design is furnished. Table 6.7 Siemens can provide an optimized design when the user specifies a dollar evaluation for no load (core) and load (conductor) losses. The evaluation formula should be stated as $___ per kilowatt core and $___ watt conductor (load). Computer generated designs will optimize for lowest total owner cost, based upon evaluated cost of electrical losses and the initial purchase price of the transformer. Design considerations include the use of low loss core steel, copper or aluminum conductor, and design temperature rise. Computer-Aided Transformer Design Sample Loss Evaluation (Using Typical Data) Standard “High Loss” Transformer Costs Initial Purchase Price = Core Loss 3200 Watts x 3.50/watt = Conductor Loss 17200 Watts x 1.75/watt = Operating Costs = Total Owner Cost (A + B) = Optional “Low Loss” Transformer $15,000.00 (A) $11,200.00 $30,100.00 $41,300.00 (B) $56,300.00 Costs Initial Purchase Price = Core Loss 2900 Watts x 3.50/watt = Conductor Loss 15400 Watts x 1.75/watt = Operating Costs = Total Owner Cost (A + B) = $18,000.00 (A) $10,150.00 $26,950.00 $37,100.00 (B) $55,100.00 Enclosures Indoor ventilated, dry type transformers are provided with 12-gauge steel enclosures finished with light gray (ANSI #61) paint. Enclosures are sized to assure proper air flow for adequate cooling. Removable front and rear covers provide access for maintenance, inspection, and de-energized tap access. The enclosure base includes provisions for jacking, lifting, skidding, or rolling the transformer. Weather Resistant Ventilated Dry Type Transformers The outdoor dry type transformer has been developed for situations which prohibit indoor installation but still require a nonflammable transformer. Optional enclosures for outdoor locations incorporate weather resistant (NEMA 3R) construction 86 Weather Resistant Enclosure Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transformer Section — Cast Coil General 6 Secondary Unit Substations Coil Construction High voltage coils are wound with insulated aluminum or copper conductor. The fully insulated coil is solidly cast in epoxy compound under vacuum to assure complete penetration to all spaces and surfaces for a complete, void free encapsulation. Coil ends and taps are brought to special terminals with internal threads which become imbedded in the casting. These terminals have a knurled outer surface to hold them against turning when leads and jumpers are bolted in place. High voltage coils utilize winding techniques which produce a continuously wound coil whereby electrical stress is reduced, giving better voltage distribution throughout the coil, and assuring complete penetration of the cast epoxy. Depending on design parameters, secondary coils are aluminum or copper conductor using the same vacuum casting method described for the epoxy cast high voltage coils, or would consist of sheet wound conductor which is insulated between layers with epoxy impregnated insulation and wrapped with polyester-glass sheets. When baked, the epoxy fuses with the insulated conductor and forms into a solid block. Epoxy is added to the layer margins to complete the casting. Insulation Cast coil transformers utilize insulating materials recognized for 185°C operation. A proprietary formula consisting of highgrade epoxy, thermally conductive mineral filler, or glass fiber cloth is used to cast the completed insulated coil. General Features 쐍 Cast Epoxy Resin is non-hygroscopic; highly resistant to moisture and industrial and chemical contamination 쐍 Excellent dynamic short circuit strength, low sound levels, high efficiency 쐍 Cast Coil insulation is virtually nonflammable and self extinguishing 쐍 No oil, no catch basins, no leakage, no valves nor gauges — minimum checking and maintenance 쐍 No environmental problems 쐍 No vaults and no special protection; can be installed at any convenient location CSI Section 16470 Legend 쐍 쐍 Unlimited storage duration and still ready for immediate application and use Vacuum Casting eliminates critical voids providing operation free of partial discharge Siemens Electrical Products and Systems Specification Guide 햲 햳 햴 햵 햶 햷 햸 햹 햺 햻 햽 Framing Bolts Core Lifting Lugs Low Voltage Bus Conductor Material Air Ducts Low voltage Coil Winding Section High Voltage Coil Support Blocks With Resilient Pads High Voltage Taps 87 Secondary Unit Substations Transformer Section — Testing and Accessories Secondary Unit Substations 6 Transformer Testing Throughout the manufacturing process and prior to shipment, all Siemens transformers are thoroughly inspected and tested according to current ANSI Standard Test Codes for transformers. Each transformer must pass the following tests: 1. Resistance measurements on all windings at the rated voltage connections of each unit and at the tap extremes of one unit only at a given rating on an order. 2. Ratio tests at the rated voltage connection and at all tap connections. 3. Polarity and phase-relation tests at the rated voltage connection. Table 6.8 4. No-load losses at the rated voltage connection. 5. Exciting current at rated voltage on the rated voltage connection. 6. Impedance and load loss at rated current on the rated voltage connection. 7. Impulse tests and temperature rise tests will be made on one unit of a given rating of an order only when a record of the temperature test made (in accordance with ANSI standards) on a duplicate or essentially duplicate unit is not available. 8. Applied potential tests. 9. Induced potential tests. 10. Partial discharge test for dry type and cast coil transformers. Standard Accessories for Transformers Description No-Load Taps햲 Provisions for Lifting Provisions for Jacking Ground Pads Instruction Nameplate Drip-Proof Roof, Special Ventilation Louvers Space Heaters 햲 햳 General Liquid Filled Ventilated Dry Type ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — 햳 — — 햳 Weather Resistant Ventilated Type ✓ ✓ ✓ ✓ ✓ ✓ ✓ Cast Coil ✓ ✓ ✓ ✓ ✓ — 햳 — 햳 Air Terminal Chamber with Distribution Arresters Taps can be changed only when transformer is de-energized. Available as an optional feature. Fan Cooling Intermediate Arresters Temperature Monitor and Fan Control Module 88 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transformer Section Technical Table 6.9 Standard Transformer Insulation Levels (kV BIL) Table 6.13 Winding Temp. Rise Hot Spot Rise Hot Spot Temp. Max. Ambient 햶 Total Temp. Rating of Insulation System % Reserve/Increase Dry Type 150°C 30°C 180°C 40°C 220°C 220°C 0% 115°C 30°C 145°C 40°C 185°C 220°C 15% 80°C 30°C 110°C 40°C 150°C 220°C 30% OA햲 65°C 336 560 840 1,120 1,680 2,240 2,800 3,360 300 500 1000 1500 2000 2500 Table 6.11 Three-Phase kVA Ratings Liquid Filled Type 55°C/65°C Rise 65°C Rise OA 햲 FA 햳 OA햲 55°C FA햳 55°C — — 300 300 — — 500 500 750 750 862 862 1,000 1,150 1,000 1,150 1,500 1,725 1,500 1,725 2,000 2,300 2,000 2,300 2,500 3,125 2,500 3,125 3,000 3,750 3,000 3,750 햲 750 Table 6.10 Standard Transformer Insulation Levels Liquid Filled 65°C 55°C 15°C 10°C 80°C 65°C 40°C 40°C 120°C 105°C 120°C 120°C 0% 12% Ventilated Cast Liquid Filled Dry Coil 55°C/65°C Rise 150°C Rise 90°C Rise Base Sec. 65°C Rise FA OA 55°C FA 55°C OA 65°C FA 65°C AA FA AA FA kVA Volts OA FA햳 65°C — — 966 1,288 1,932 2,576 3,500 4,200 Ventilated Dry Type 150°C Rise FA햳 AA햴 300 400 500 667 750 1,000 1,000 1,333 1,500 2,000 2,000 2,667 2,500 3,333 3,000 4,000 3000 208 240 480 600 208 240 480 600 208 240 480 600 208 240 480 600 480 600 480 600 480 600 480 600 Table 6.14 Transformer Type Liquid Filled Table 6.12 Standard Transformer High Voltage Taps Rated Transformer Voltage 2,400 4,160 4,800 6,900 7,200 12,000 12,470 13,200 13,800 High Voltage Taps +5% 2,520 4,368 5,040 7,245 7,560 12,600 13,094 13,860 14,490 햲 햳 햴 햵 +21/2% 2,460 4,264 4,920 7,073 7,380 12,300 12,7802 13,530 14,145 OA—Self-cooled FA—Forced-air-cooled AA—Self-cooled For Standard BIL Ratings 햶 Average ambient is 30˚C for 24 hour period. CSI Section 16470 –21/2% 2,340 4,056 4,680 6,728 7,020 11,700 12,158 12,870 13,455 –5% 2,280 3,952 4,560 6,555 6,840 11,400 11,845 12,540 13,110 햳 — — — — — — — — 2396 2075 1038 830 3194 2767 1383 1106 2075 1659 2767 2213 3759 3008 4510 3608 Ventilated Dry Type Cast Coil 834 722 361 289 1388 1203 601 481 2080 1804 902 722 2780 2406 1203 962 1804 1444 2406 1924 3010 2406 3608 2887 햲 햳 — — — — — — — — 2396 2075 1038 830 3194 2767 1383 1106 2075 1659 2767 2213 3759 3008 4510 3608 햳 933 808 404 323 1556 1347 674 539 2333 2021 1011 808 3111 2695 1347 1077 2021 1616 2696 2155 3368 2694 4041 3233 햳 — — — — — — — — 2683 2324 1162 929 3578 3099 1549 1239 2324 1859 3099 2478 4211 3367 5052 4041 834 722 361 289 1388 1203 601 481 2080 1804 902 722 2780 2406 1203 962 1804 1444 2406 1924 3010 2406 3608 2887 햴 834 722 361 289 1388 1203 601 481 2080 1804 902 722 2780 2406 1203 962 1804 1444 2406 1924 3010 2406 3608 2887 햳 햴 — — — — — — — — 2778 2406 1203 962 3704 3208 1604 1283 2406 1924 3208 2565 4010 3208 4811 3849 834 722 361 289 1388 1203 601 481 2080 1804 902 722 2780 2406 1203 962 1804 1444 2406 1924 3010 2406 3608 2887 햳 — — — — — — — — 2778 2406 1203 962 3704 3208 1604 1283 2406 1924 3208 2565 4010 3208 4811 3849 Transformer Dielectric Tests 햵 Voltage Class (kV) 1.2 2.5 5.0 8.6 15.0 1.2 2.5 5.0 8.6 15.0 1.2 2.5 5.0 8.6 15.0 Applied Test 60 Hertz All kVA Ratings (kV) 10 15 19 26 34 4 10 12 19 31 4 31 31 34 34 Basic Impulse Levels 1.2 x 50 ms (kV) 30 45 60 75 95 10 20 30 45 60 10 60 75 95 95 Induced Test 7200 Hertz All kVA Ratings Twice Normal Voltage Twice Normal Voltage Twice Normal Voltage Table 6.15 Surge Arrester Characteristics System Voltage 2,400 4,160 4,800 6,900 8,300 12,000 12,470 13,200 13,800 Siemens Electrical Products and Systems Specification Guide Arrester Rating (kV Class) Effectively Grounded System — 6 6 — 6 9 9 10 10 Ungrounded System 3 6 6 9 9 15 15 15 15 89 Secondary Unit Substations Transformer Liquid Filled Ventilated Dry Cast Coil Dry Type High Transformer Type Transformer Transformer Voltage Rating HV LV (600 Max) HV LV (600 Max) HV LV (600 Max) 2,400 45 60 30 30 10 30 4,160 60 75 30 30 10 30 4,800 60 75 30 30 10 30 6,900 75 95 30 30 10 45 7,200 75 95 30 30 10 45 12,000 95 95 30 30 10 60 12,470 95 95 30 30 10 60 13,200 95 95 30 30 10 60 13,800 95 95 30 30 10 60 6 Three-Phase Secondary Ampere Ratings Secondary Unit Substations Transformer Section Secondary Unit Substations 6 Table 6.16 Normal Load and Fault Currents (Secondary) of Three-Phase Transformers Transformer Rating 3 Phase kVA and Impedance %햲 Maximum Short Circuit kVA Available from Primary System 300 5% 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 Unlimited 50000 100000 150000 250000 500000 500 5% 750 5.75% 1000 5.75% 1000 8% 1500 5.75% 2000 5.75% 2500 5.75% 3000 5.75% Technical 208 Volts, 3-Phase Rated Short-Circuit Current Load RMS Symmetrical Amps Continuous 50% Trans- Motor CurComformer Load rent, bined Amps. Alone 햳 834 1388 2080 2780 14900 15700 16000 16300 16500 16700 21300 25200 26000 26700 27200 27800 28700 32000 33300 34400 35200 36200 35900 41200 43300 45200 46700 48300 1700 2800 4200 5600 16600 17400 17700 18000 18200 18400 25900 28000 28800 29500 30000 30600 32900 36200 37500 38600 39400 40400 41500 46800 48900 50800 52300 53900 240 Volts, 3-Phase Rated Short-Circuit Current Load RMS Symmetrical Amps Continuous 100% CurTrans- Motor rent, Comformer Load Amps. Alone 햳 bined 722 1203 1804 2406 12900 13600 13900 14100 14300 14400 20000 21900 22500 23100 23600 24100 24900 27800 28900 29800 30600 31400 31000 35600 37500 39100 40400 41800 2900 4800 7200 9600 15800 16500 16800 17000 17200 17300 24800 26700 27300 27900 28400 28900 32100 35000 36100 37000 37800 38600 40600 45200 47100 48700 50000 51400 480 Volts, 3-Phase Rated Short-Circuit Current Load RMS Symmetrical Amps Continuous 100% CurTrans- Motor rent, former Load ComAmps. Alone 햳 bined 361 601 902 1203 1203 — — — — — — — — — — — 3609 41200 49800 53500 56800 59600 62800 14400 55600 64200 57900 71200 74000 77200 — 1804 2406 — — — — — — — — 3008 — — — — — — — — 3608 — — — — — — — — 6400 6800 6900 7000 7100 7200 10000 10900 11300 11600 11800 12000 12400 13900 14400 14900 15300 15700 15500 17800 18700 19600 20200 20900 12030 13350 13980 14315 14555 15040 20600 24900 26700 28400 29800 31400 24700 31000 34000 36700 39100 48100 28000 36500 40500 44600 48100 52300 33600 43800 48600 53520 57720 62755 Unlimited 1400 2400 3600 4800 4800 7200 9600 12000 14400 7800 8200 8300 8400 8500 8600 12400 13300 13700 14000 14200 14400 16000 17500 18000 18500 18900 19300 20300 22600 23500 24400 25000 25700 16830 18150 18750 19115 19355 19840 27800 32100 33900 35600 37000 38600 34300 40600 43600 46300 48700 51400 40000 48500 52500 56600 60100 64300 48000 58200 63000 67920 72120 77160 600 Volts, 3-Phase Rated Short-Circuit Current Load RMS Symmetrical Amps Contin100% uous Trans- Motor Curformer Load rent, Com햳 Amps. Alone bined 5200 5500 5600 5600 5700 5800 8000 8700 9000 9300 9400 9600 10000 11100 11600 11900 12200 12600 12400 14300 15000 15600 16200 16700 1200 — — — — 1444 16500 20000 21400 22700 23900 25100 19700 24800 27200 29400 31300 33500 22400 29200 32400 35600 38500 41800 26880 35040 38880 42720 46200 5800 22300 25800 27200 28500 29700 30900 27500 32600 35000 37200 39100 41300 32000 38800 42000 45200 48100 51400 38400 46560 50400 64240 57720 289 481 722 962 1924 2405 2887 50160 1900 2900 3900 7800 9600 11520 6400 6700 6800 6800 6900 7000 9900 10600 10900 11200 13000 11500 12900 14000 14500 14800 15100 15500 16300 18200 18900 19500 20100 20600 61680 햲 Short circuit currents are calculated with impedences and kVA shown in this table. Impedances are typical values. 햳 Short circuit current contributions are calculated on the basis of motor characteristics that will produce four times normal circuit. 50% motor load contribution is assumed for 208V and 100% motor load contribution is assumed for 240V, 480V and 600V. 90 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transformer Section — Liquid Filled Dimensions 6 Secondary Unit Substations 5kV and 15kV Liquid-Filled Transformer Table 6.17 5kV and 15kV R-Temp or Silicone Liquid Transformers kVA Rating 500 750 1000 1500 2000 2500 65°C Temp. Rise Dimensions in Inches (mm) A B 70.5 (1791) 59.5 (1511) 72.5 (1842) 81.0 (2057) 74.5 (1892) 75.0 (1905) 79.5 (2019) 81.0 (2057) 79.5 (2019) 102.5 (2604) 79.5 (2019) 110.5 (2807) C 52.00 (1321) 53.00 (1346) 56.00 (1422) 59.00 (1499) 59.00 (1499) 59.00 (1499) D 21.50 (546) 40.50 (1029) 40.50 (1029) 40.50 (1029) 53.25 (1353) 57.25 (1454) Weight Lb. (kg) 4190 (1901) 6450 (2926) 7630 (3461) 9500 (4309) 12070 (5475) 14190 (6437) 55°C/65°C Temp. Rise Dimensions in Inches (mm) A B 70.5 (1791) 76.0 (1930) 72.5 (1842) 81.0 (2057) 80.5 (2045) 81.0 (2057) 80.5 (2045) 103.5 (2629) 89.5 (2273) 122.5 (3112) 89.5 (2273) 130.5 (3315) C 52.00 (1321) 53.00 (1346) 56.00 (1422) 59.00 (1499) 59.00 (1499) 59.00 (1499) D 38.00 (965) 40.50 (1029) 40.50 (1029) 51.75 (1314) 61.25 (1556) 65.25 (1657) 55°C/65°C Temp. Rise Dimensions in Inches (mm) A B 70.5 (1791) 53.5 (1359) 70.5 (1791) 75.0 (1905) 70.5 (1791) 81.0 (2057) 72.5 (1842) 81.0 (2057) 76.5 (1943) 98.5 (2502) 76.5 (1943) 106.5 (2705) 76.5 (1943) 106.5 (2705) 77.5 (1969) 124.5 (3162) C 52.00 (1321) 53.00 (1346) 56.00 (1422) 59.00 (1499) 59.00 (1499) 59.00 (1499) 70.00 (1778) 72.00 (1829) D 21.50 (546) 40.50 (1029) 40.50 (1029) 40.50 (1029) 49.25 (1251) 53.25 (1353) 53.25 (1353) 62.25 (1581) Weight Lb. (kg) 4390 (1991) 6890 (3125) 8350 (3788) 11300 (5126) 13920 (6314) 15230 (6908) Table 6.18 5kV and 15kV Oil Filled Transformers kVA Rating 500 750 1000 1500 2000 2500 3000 3750 햲 Consult 65°C Temp. Rise Dimensions in Inches (mm) A B 70.5 (1791) 53.5 (1359) 70.5 (1791) 58.5 (1486) 70.5 (1791) 64.5 (1638) 72.5 (1842) 64.5 (1638) 76.5 (1943) 78.0 (1981) 76.5 (1943) 84.0 (2134) 76.5 (1943) 98.5 (2502) 77.5 (1969) 108.5 (2756) C 52.00 (1321) 53.00 (1346) 56.00 (1422) 59.00 (1499) 59.00 (1499) 59.00 (1499) 70.00 (1778) 72.00 (1829) D 21.5 (546) 24.0 (610) 24.0 (610) 24.0 (610) 36.0 (914) 42.0 (1067) 49.25 (1251) 54.25 (1378) Weight Lb. (kg) 4100 (1860) 6200 (2812) 7140 (3239) 8800 (3992) 10250 (4649) 13730 (6228) 햲 햲 Weight Lb. (kg) 4270 (1937) 6420 (2912) 7720 (3502) 9550 (4332) 10650 (4831) 14250 (6464) 햲 햲 Siemens for weight. Note: Dimensions and weights on this page are for estimating purposes only, not for construction. CSI Section 16470 Siemens Electrical Products and Systems Specification Guide 91 Secondary Unit Substations Transformer Section — Dry Type, Cast Coil Dimensions 6 Secondary Unit Substations 10.5 in. (266.7 mm) DANGER H + 3.25 in. (82.6 mm) 8.0 in. (203.2 mm) FAN CONTROL PANEL FRONT 2.75 in. (69.85 mm) GROUND BUS 8.0 in. (203.2 mm) 12.63 in. (320.8 mm) 4.0 in. (101.6 mm) 1.81 in. (45.97 mm) High Voltage Terminal Table 6.19 W Front View Outdoor 5kV and 15kV Ventilated Dry Type Transformers 115˚C or 150˚C Temp Rise 5 kV = 30 kV BIL, 15 kV = 60 kV BIL 80˚C Temp Rise 5 kV = 30 kV BIL, 15 kV = 60 kV BIL Approx. Dim. in Inches (mm) weight— W D Lbs. (kg) H 48 90 48 2,200 (1219) (2286) (1219) (998) Dim. in Inches (mm) kVA W D Rating H 48 48 90 225 (1219) (1219) (2286) Approx. weight— Lbs. (kg) 2,500 (1134) 115˚C or 150˚C Temp Rise 5 kV = 60 kV BIL, 15 kV = 95 kV BIL Approx. Dim. in Inches (mm) weight— H W D Lbs. (kg) 80˚C Temp Rise 5 kV = 60 kV BIL, 15 kV = 95 kV BIL Dim. in Inches (mm) H W D Approx. weight — Lbs. (kg) — — — — — — — — 300 90 (2286) 78 (1981) 48 (1219) 2,500 (1134) 90 (2286) 78 (1981) 48 (1219) 3,150 (1429) 90 (2286) 78 (1981) 48 (1219) 3,150 (1429) 90 (2286) 78 (1981) 48 (1219) 3,300 (1499) 500 90 (2286) 78 (1981) 48 햲 (1219) 3,150 (1429) 90 (2286) 78 (1981) 48 햲 (1219) 4,150 (1882) 90 (2286) 78 (1981) 48 (1219) 4,150 (1882) 90 (2286) 78 (1981) 48 햲 (1219) 4,400 (1996) 750 90 (2286) 78 (1981) 48 햲 (1219) 4,150 (1882) 90 (2286) 78 (1981) 48 햲 (1219) 5,050 (2291) 90 (2286) 90 (2286) 58 (1473) 5,100 (2313) 90 (2286) 90 (2286) 58 (1473) 5,500 (2495) 1000 90 (2286) 78 (1981) 48 햲 (1219) 5,050 (2291) 90 (2286) 78 (1981) 48 햲 (1219) 6,550 (2971) 90 (2286) 90 (2286) 58 (1473) 6,600 (2994) 90 (2286) 102 (2591) 58 (1473) 7,400 (3357) 1500 90 (2286) 90 (2286) 48 햲 (1219) 6,700 (3039) 90 (2286) 90 (2286) 48 햲 (1219) 8,050 (3652) 90 (2286) 102 (2591) 58 (1473) 8,050 (3652) 90 (2286) 112 (2845) 58 (1473) 14,000 (6350) 2000 90 (2286) 90 (2286) 58 (1473) 8,050 (3652) 90 (2286) 102 (2591) 58 (1473) 13,000 (5897) 90 (2286) 112 (2845) 58 (1473) 13,000 (5897) 102 (2591) 112 (2845) 58 (1473) 14,000 (6350) 2500 102 (2591) 112 (2845) 58 (1473) 13,000 (5897) 102 (2591) 112 (2845) 58 (1473) 16,000 (7258) 102 (2591) 112 (2845) 58 (1473) 16,000 (7258) 110 (2794) 112 (2845) 58 (1473) 16,000 (7258) 3000 110 (2794) 120 (3048) 58 (1473) 14,000 (6350) 110 (2794) 120 (3048) 58 (1473) 18,000 (8165) 110 (2794) 120 (3048) 58 (1473) 18,000 (8165) 110 (2794) 120 (3048) 58 (1473) 18,000 (8165) Table 6.20 5kV and 15kV Cast Coil Type Transformers 115˚C or 80˚C 5 kV = 75 kV BIL kVA Rating 햲 1.81 in. (45.97 mm) 115˚C or 80˚C Rise 15 kV = 95 kV BIL Dim. in Inches (mm) H W Weight in Lbs. (kg) D Approx. Weight in Lbs. (kg) Dim. in Inches (mm) H W D 500 90 (2286) 90 (2286) 58 (1473) 5,200 (2359) 90 (2286) 90 (2286) 58 (1473) 5,400 (2449) 750 90 (2286) 96 (2438) 58 (1473) 6,900 (3130) 90 (2286) 96 (2438) 58 (1473) 7,200 (3266) 1000 90 (2286) 102 (2591) 58 (1473) 8,400 (3810) 90 (2286) 96 (2438) 58 (1473) 8,500 (3856) 1500 90 (2286) 108 (2743) 58 (1473) 11,200 (5080) 96 (2438) 102 (2591) 58 (1473) 12,900 (5851) 2000 102 (2591) 114 (2896) 58 (1473) 13,200 (5988) 102 (2591) 114 (2896) 58 (1473) 13,900 (6305) 2500 108 (2743) 120 (3048) 58 (1473) 15,300 (6940) 108 (2743) 120 (3048) 58 (1473) 15,900 (7212) 3000 114 (2896) 126 (3200) 58 (1473) 18,200 (8256) 114 (2896) 126 (3200) 58 (1473) 18,900 (8573) 208V secondary requires 58 in. (1473 mm) deep enclosure. 92 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Transition Section General 6 Secondary Unit Substations A transition section is required between the transformer and the primary section, and between the main device section of the switchboard for a liquid filled transformer. Connection between the transformer secondary and the main bus of the switchboard is made with flexible connectors. Transition Section Flexible Connectors Between Transformer Secondary and Main Bus of Switchboard Table 6.21 High Voltage Transition Section Between Primary Switch and Transformer Transformer Oil, RTEmp, Silicone Width in Inches (mm) Depth 햲 20 (508) Ventilated Dry Type 햳 20 (508) 햲 Outdoor Cast-Coil 햳 20 (508) 햲 햲 Same depth as primary switch section. 햳 Transition section is not required (optional). Table 6.22 Low Voltage Transition Section Between Transformer and Low Voltage Switchboard Dimensions in Inches (mm) Ventilated Dry Type and Liquid Filled Cast Coil Transformer Transformer 햳 Amp Rating W D W D 600 20 20 햲 햲 800 (508) (508) 10000 1200 20 20 햲 햲 1600 (508) (508) 2000 2500 20 20 햲 햲 3000 (508) (508) 4000 햲 Same depth as primary switch section. 햳 Transition section is not required (optional). Switchboard secondary defines requirements. Consult Siemens for specific requirements. CSI Section 16470 Siemens Electrical Products and Systems Specification Guide 93 Secondary Unit Substations Transition Section Dimensions 6 Type SB3 Front-Connected Switchboard 햲 Secondary Unit Substations With Liquid Filled Transformer With Ventilated Dry Type or Cast Coil Transformer 48 in. (1219 mm) or 58 in. (1473 mm) Distribution Section Type RCIII Rear-Connected Switchboard 햲 With Liquid Filled Transformer With Dry Type or Cast Coil Transformer 48.0 in. (1219 mm) or 58 in. (1473 mm) 햲 For exact switchboard dimensions, see pages 120 through 134. 94 Siemens Electrical Products and Systems Specification Guide CSI Section 16470 Secondary Unit Substations Secondary Distribution Section Reference 6 Table 6.23 Secondary Unit Substations 햲 햳 햴 햵 햶 HV Switch HV Transition Liquid Transformer LV Transition LV Switchboard or Switchgear Section Secondary Section Reference To Find… Secondary Section General Data, Page Dimensional Data, Page Type SB3 Switchboard Type RCIII Switchboard Type R Low Voltage Switchgear 99 99 120 121 50 63 햲 HV Switch 햳 Dry Typa or Cast Coil Transformer 햴 LV Switchboard or Switchgear Section Table 6.24 — Reference for Secondary Section Devices To Find… Disconnect Device Molded Case Circuit Breakers Fusible Switches Bolted Pressure Switches Insulated Case Circuit Breakers LV Power Air Circuit Breakers CSI Section 16470 Technical Data, Pages 110–111 110, 112 110, 112 109, 112 108, 112 Meets Standard Dimensional Data, Page 121 121 121 121 121 Siemens Electrical Products and Systems Specification Guide NEMA PB-2 ✓ ✓ ✓ ✓ SG-5 — — — — — ✓ UL 891 ✓ ✓ ✓ ✓ 1558 — — — — — ✓ ANSI C37-20 ✓ — — — ✓ 95 Secondary Unit Substations Guide Form Specifications Secondary Unit Substations 6 I. General A. Scope This specification covers an (indoor) (outdoor) secondary unit substation complete from the incoming line terminals to the outgoing feeder terminals. The unit substation shall be arranged in accordance with sketch _____ accompanying this specification. The substation shall include the following sections, arranged from (left to right) when facing the front of the substation. 쐍 Incoming Line Section 쐍 Transformer Section 쐍 Outgoing Switchboard Section B. Ratings The substation ratings shall be: Selfcooled _____ VA; Fan-cooled _____ kVA; 3-Phase, 60 Hz _____; Incoming (3) (4)-wire circuits _____ kV; Outgoing (3) (4)-wire circuits _____ volts. II. Incoming Line Section (Select one of Item A) A(1). Air Interrupter Switch The incoming high voltage switch shall be manually operated, rated (5kV) (15kV), (600) (1200) amperes continuous, with a fault close rating of (40) (61) kA symmetrical. The switch shall be quick-make, quick-break. The switch shall be floor mounted, metal enclosed and close coupled to the transformer section. The switch shall be 3-pole, 2-position air insulated. A window in front of the switch shall permit visual inspection of Specifications the switch contacts. The switch shall be operable from the front of the unit. to the high voltage side of the transformer. It shall be rated (5kV) (15kV). A(2). Duplex Switch The incoming high voltage switch shall be a 3-pole, 2-position duplex switch which includes two load interrupter switches connected together on the load side. This will permit connection of the transformer to one of two incoming lines. Each switch will be manually operated, rated (5kV) (15kV), (600) (1200) amperes continuous, with a fault close rating of (40) (61) kA symmetrical. The two switches will be interlocked to prevent both incoming sources from being connected to the transformer at the same time. Each switch shall have a window in front to permit visual inspection of the switch contacts. Each switch shall also be operable from the front of its respective unit. B. Fuses (Optional with A1, A2, and A3 above) The switch shall be equipped with three (current-limiting) (expulsion) fuses. Access to fuse compartments will be through single front door. The door shall be kirk key interlocked with the switch mechanism so that the switch must be in open position before the door can be opened. Conversely, the door must be closed and locked and the key returned to the switch before the switch can be closed. A(3). Selector Switch The incoming high voltage switch shall be a 3-pole, 2-position (Line 1-Line 2) 600 ampere selector switch in series with a 600 ampere 3-pole, 2-position (On-Off) interrupter switch rated (5kV) (15kV). Mechanical interlocking shall be provided so that the load interrupter switch must be open before the selector switch can be changed from one feeder to another. The selector switch and air interrupter switch shall be operable from the front of its respective unit. C. Incoming Cable Cable is to enter from (above) (below) and terminate in (1) (2) clamp type lugs per phase, or (1-3/C) (2-3/C) (3-1/C) (6-1/C) pothead(s) for ______ single feed, ______ loop feed termination. Incoming cable to be (5kV) (15kV), ______ size, type ______ insulation. For potheads, provide the following information: ______OD over insulation ______OD conductor ______OD overall D. Lightning Arresters Provide three _______kV (distribution) (intermediate) (station type) arresters for _______kV (grounded) (ungrounded) service. A(4). Air Terminal Chamber This section shall consist of a full height air terminal chamber directly connected E. Additional Interlocks Provide ______ key interlock(s) to interlock with _______. Ill. Transformer Section (Select one of Item A) High Voltage _____ delta Low Voltage _____ wye (delta) A(1). Liquid Filled Transformer Furnish and install transformers of the two winding type, three-phase, 60 Hertz, with ratings as indicated. Unless specified otherwise, provide standard NEMA taps, standard impedance, and standard sound levels. Transformers shall be liquid filled type designed, manufactured, and tested in accordance with applicable ANSI, NEMA, IEEE standards. The core and coil construction shall be the most efficient, reliable, and compact design suitable for secondary unit substation application. The self-cooled kVA rating shall be suitable for 30°C average, 40°C maximum ambient temperature. Basic Impulse Level The basic impulse level (BIL) for the transformer shall be standard BIL ratings as indicated (optional ratings as indicated): Fluid The transformer insulating and cooling fluid shall be mineral oil (standard); R-Temp (Silicone) high-firepoint fluid. Rating The transformer shall be rated 3-phase, 60 hertz as follows: kVA: _____ selfcooled, (AA) 96 Voltage Class 5kV 15kV Std. BIL 60kV 95kV Opt. BIL 75kV 110kV Temperature Rise Temperature rise shall not exceed 65°C at rated kVA (55 / 65°C rise optional). Conductor Material The conductors shall be an electrical grade aluminum material (copper optional). Insulation Materials All insulation materials for the primary and secondary coil assembly shall be rated for continuous 120° total temperature. Siemens Electrical Products and Systems Specification Guide Core and Coil Assembly The core shall be constructed of nonaging, cold-rolled, grain-oriented, high permeability silicon steel. The core framing structure shall be of rigid construction to provide full clamping pressure upon the core and provide the support points for the coils. The HV and LV coils shall be continuously wound. Coils shall be adequately braced for full short circuit capability. High Voltage Taps Provided two 21/2% minus and two 21/2% plus de-energized full capacity taps. Tap changer handle to be externally accessible and capable of being locked in any tap position. CSI Section 16470 Secondary Unit Substations Guide Form Specifications Sound Level The transformer shall be designed to meet the sound level standards for transformers as defined in ANSI. Future Forced-Air Cooling (optional) Transformer shall have provisions for future addition of forced air cooling. (OA / FFA). Forced-Air Cooling (optional) A complete forced-air cooling system (OA / FA) shall be provided for automatically increasing the self-cooled rating. Accessories All NEMA standard accessories shall be provided, including: 쐍 Padlockable no-load tap changer 쐍 Pressure relief device 쐍 Welded tank cover with hand hole 쐍 Pressure vacuum gauge 쐍 Dial type thermometer 쐍 Magnetic liquid level gauge 쐍 Instruction nameplate 쐍 Provision for lifting and jacking 쐍 Filter press connection 쐍 Drain and sampling valve 쐍 Ground pad Tests The following tests shall be performed on each unit in accordance with ANSI standards: 쐍 No-load losses 쐍 Excitation current 쐍 Resistance measurement 쐍 Ratio test 쐍 Polarity and phase-relations test 쐍 Impedance and load-loss 쐍 Applied potential test 쐍 Induced potential test Design coordination for the entire unit substation shall be from one manufacturer and shall be Siemens or approved equal. A(2). Ventilated Dry Type Transformer Furnish and install transformers of the two winding type, three-phase, 60 Hertz, with ratings as indicated. Unless specified otherwise, provide standard NEMA transformer standard impedance. and standard sound levels. Transformers shall be UL Listed conventional dry type, and shall be designed, CSI Section 16470 manufactured, and tested in accordance with applicable ANSI, NEMA, IEEE standards. The core and coil construction shall be the most efficient, reliable, and compact design suitable for secondary unit substation application. The self-cooled kVA rating shall be suitable for 30°C average, 40°C maximum ambient temperature. Rating The transformer shall be rated 3-phase, 60 Hertz as follows: kVA:____self-cooled, (AA) High Voltage ___ delta Low Voltage ___ wye (delta) HV taps: Full capacity with 2-21/2% above and below rated high voltage. Basic Impulse Level The basic impulse level (BIL) for the transformer shall be standard BIL ratings as indicated (optional ratings as indicated): Voltage Class 5kV 15kV Std. BIL 60kV 95kV Opt. BIL 75kV 110kV Temperature Rise: Temperature rise shall not exceed 150°C at rated kVA (115°C or 80°C rise optional). Conductor Material The conductors shall be an electrical grade aluminum material (copper optional). K-Factor Rated (optional) Non-linear rated transformers shall be suitable for non-sinusoidal loads and harmonic distortion as indicated in IEEE C57.110, and shall be designed with one of the following K-Factor ratings: K4 for 50% non-linear load K13 for 100% non-linear load K20 for 150% non-linear load K30 for 200% non-linear load Non-linear rated transformers shall bear the specified K-Factor rating on the nameplate. Non-linear-rated transformers shall include the following design features: a) Core designed to withstand voltage distortion and high frequency harmonic currents. Magnetic flux density designed to reduce eddy currents and prevent saturation or overheating of the core. b) Primary and secondary coils designed to minimize stray losses, skin effect losses, and excessive heating from harmonic currents. Coils shall not exceed the specified winding temperature rise, the corresponding hot spot temperature rating, or the 220°C insulation rating while carrying the specified non-linear load. Siemens Electrical Products and Systems Specification Guide 6 Insulation Materials All insulation materials for the primary and secondary coil assembly shall be rated for continuous 220°C total temperature (Class H), and shall be UL approved insulation system. Core and Coil Assembly The core shall be constructed of nonaging, cold-rolled, grain-oriented, high permeability silicon steel. All core laminations shall be free of burrs and shall be stacked without gaps. The core framing structure shall be of rigid construction to provide full clamping pressure upon the core and provide the support points for the coils. The HV and LV coils shall be continuously wound. Coils shall be adequately braced for full short circuit capability. Vibration dampening pads shall be provided to isolate core / coil assembly from the base structure. VPI Process Transformers shall be sealed and protected using a Vacuum Pressure Impregnation (VPI) process. The oreheated windings shall be subjected to a dry vacuum cycle, followed by wet vacuum cycle during which windings are impregnated with resin, then followed by a pressure cycle to force the resin through the insulation. The windings shall bye oven cured to bind the resin to the insulation material. The VPI and oven curing process shall completely seal and protect the windings from moisture and dirt, and shall eliminate any voids which could create hot spots, partial discharge, or cause corona formation. Dip and bake impregnation is not acceptable. High Voltage Taps Tap leads shall be terminated at the coils and equipped with provisions for changing taps under de-energized conditions. Enclosure The enclosure shall be NEMA 1 Indoor type (NEMA 3R outdoor optional) constructed of heavy gauge sheet steel equipped with removable panels for access to the core and coils on the front and rear sides. Ventilated openings shall be furnished to meet NEMA standards. The enclosure shall include provisions for rolling, skidding, lifting, and jacking for installation. Enclosure finish shall be in the manufacturer’s standard light gray paint. Sound Level The transformer shall be designed to meet the sound level standards for dry type transformers as defined in ANSI C89.2 I NEMA ST-20. 97 Secondary Unit Substations Enclosure The enclosure tank shall be welded steel plate construction providing a sealed-tank system. The enclosure tank shall include provisions for rolling, skidding, lifting, and jacking for installation. Paint finish shall be the manufacturer’s standard light gray. Specifications Secondary Unit Substations Guide Form Specifications Secondary Unit Substations 6 Future Forced-Air Cooling (optional) Transformer shall have provisions for future addition of forced air cooling (AA / FFA). Forced-Air Cooling (optional) A complete forced-air cooling system (AA / FA) shall be provided for automatically increasing the self-cooled rating by 331/3%. The forced cooling system shall be a solid state device with continuous temperature monitoring within each phase. Features shall include test switches, digital temperature indication for each phase or highest temperature, manual or automatic fan control switches, audible alarm silencing switch, memory, and self-test. Accessories All NEMA standard accessories shall be provided, including: 쐍 HV / LV Bus terminations 쐍 Removable panels 쐍 Provisions for grounding 쐍 Instruction nameplate Tests The following tests shall be performed on each unit in accordance with ANSI standards: 쐍 No-load losses 쐍 Excitation current 쐍 Resistance measurement 쐍 Ratio test 쐍 Polarity and phase-relations test 쐍 Impedance and load-loss 쐍 Applied potential test 쐍 Induced potential test 쐍 Partial discharge Design coordination for the entire unit substation shall be from one manufacturer and shall be Siemens or approved equal. A(3). Cast Coil Transformer Furnish and install transformers of the two winding type, three-phase, 60 Hertz, with ratings as indicated. Unless specified otherwise, provide standard NEMA taps, standard impedance, and standard sound levels. Transformers shall be cast coil type and shall be designed, manufactured, and tested in accordance with applicable ANSI, NEMA, IEEE standards. The core and coil construction shall be the most efficient, reliable, and compact design suitable for secondary unit substation application. The self-cooled kVA rating shall be suitable for 30°C average, 40°C maximum ambient temperature. 98 Specifications Rating The transformer shall be rated 3-phase, 60 Hertz as follows: kVA: ___ High Voltage ____delta Low Voltage_____wye (delta) HV taps: Full capacity with 2-21/2% above and below rated high voltage. Basic Impulse Level The basic impulse level (BIL) for the transformer shall be standard BIL ratings as indicated (optional ratings as indicated): Voltage Class Std. BIL Opt. BIL 5kV 15kV 60kV 95kV 75kV 110kV Temperature Rise: Temperature rise shall not exceed 80°C at rated kVA (115°C optional). Conductor Material The conductors shall be an electrical grade aluminum material (copper optional). Insulation Materials All insulation materials for the primary and secondary coil assembly shall be rated for continuous 185°C temperature. Core and Coil Assembly The core shall be cruciform shape constructed of non-aging, cold-rolled, grainoriented, high permeability silicon steel. All core laminations shall be free of burrs and shall be stacked without gaps. The core framing structure shall be of rigid construction to provide full clamping pressure upon the core and provide the support points for the coils. The HV and LV coils shall be continuously wound. Coils shall be adequately braced for full short circuit capability. The entire high voltage winding shall be solidly cast in epoxy resin using a vacuum process to insure the absence of voids. Each high voltage winding shall be tested after casting to verify the absence of voids. The low voltage windings shall be the same construction as used for the high voltage windings, or constructed of sheet wound conductor with epoxy impregnated insulation between the layers which, when baked, forms the coil into a solid epoxy casting. Vibration dampening pads shall be provided to isolate core / coil assembly from the base structure. High Voltage Taps Tap leads shall be studs terminated on the coils and equipped with bolted provisions for changing taps under de-energized conditions. Siemens Electrical Products and Systems Specification Guide Enclosure The enclosure shall be NEMA 1 Indoor type (NEMA 3R outdoor optional) constructed of heavy gauge sheet steel equipped with removable panels for access to the core and coils on the front and rear sides. Ventilated openings shall be furnished to meet NEMA standards. The enclosure shall include provisions for rolling, skidding, lifting, and jacking for installation. Enclosure finish shall be in the manufacturer’s standard light gray paint. Sound Level The transformer shall be designed to meet the sound level standards for transformers as defined in ANSI. Future Forced-Air Cooling (optional) Transformer shall have provisions for future addition of forced air cooling (AA / FFA). Forced-Air Cooling (optional) A complete forced-air cooling system (AA / FA) shall be provided for automatically increasing the self-cooled rating by 331/3%. The forced cooling system shall be a solid state device with continuous temperature monitoring. Features shall include test switches, digital temperature indication for each phase or highest temperature, manual or automatic fan control switches, audible alarm silencing switch, memory, and self-test. Accessories All NEMA standard accessories shall be provided, including: 쐍 HV / LV Bus terminations 쐍 Removable panels 쐍 Provisions for grounding 쐍 Instruction nameplate Tests The following tests shall be performed on each unit in accordance with ANSI standards: 쐍 No-load losses 쐍 Excitation current 쐍 Resistance measurement 쐍 Ratio test 쐍 Polarity and phase-relations test 쐍 Impedance and load-loss 쐍 Applied potential test 쐍 Induced potential test 쐍 Partial discharge Design coordination for the entire unit substation shall be from one manufacturer and shall be Siemens or approved equal. CSI Section 16470
