City and County of San Francisco
Office of Contract Administration
Purchasing
ITSF 15000556/CD
Attachment B-7
SECTION 261313 – MEDIUM VOLTAGE VACUUM FAULT INTERRUPTERS
PART 1 - GENERAL
1.1
A.
SUMMARY
This specification covers the requirements for underground submersible solid dielectric
insulated manually operated load break switches and electronically controlled
resettable vacuum fault interrupters (VFIs). All switch assemblies shall include load
break switch ways and fault interrupter ways, as indicated on the single line diagrams.
1.
B.
1.2
A.
The manufacturer shall be ISO 9001:2008 and ISO 14001:2004 certified.
ACTION SUBMITTALS
Product Data: For each type of switch assembly (with switches and/or fault
interrupters) and related equipment, include the following:
1.
2.
3.
B.
1.3
Switch assemblies shall be as manufactured G&W Electric, S&C Electric,
Thomas & Betts (Elastimold), or approved equal
Rated capacities, operating characteristics, furnished specialties, and
accessories for individual interrupter switches and circuit breakers.
Time-current operating characteristic curves for phase and ground overcurrent
protective devices.
Control and SCADA interface devices.
Shop Drawings: For each type of switch assembly and related equipment, provide the
following:
1.
Dimensioned plans, elevations, sections, and details, including required work
clearances and service space around equipment.
2.
Weights, anchoring, and seismic bracing.
3.
Show method of field assembly, location and size of each field connection.
4.
Wiring Diagrams: power, signal, and control wiring.
INFORMATIONAL SUBMITTALS
A.
Submit under provisions of Division 26 Section "Common Results for Electrical Review of Materials" and Division 01 Section "General Requirements."
B.
Drawings: Provide five (5) copies, reflecting the current design, for review and
SFPUC's information. SFPUC review comments must be incorporated on drawings
before manufacturing release. Provide five (5) copies of the following final drawings at
time of shipment:
1.
Outline drawings showing overall assembly and drawings illustrating physical
arrangement (plan, front and side views), shipping splits, lifting provisions and
261313-1
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
ITSF 15000556/CD
Attachment B-7
total weight. Drawings shall show detail requirement for field assembly of VFIs.
Installation drawings include VFI footprints, recommended mounting details,
provisions for conduit entrances, terminations assembly and access
requirements for installation and maintenance.
Layout drawings showing device locations.
Bill of materials describing materials and devices used. Submit for each VFI
lineup, with an overall summary total for devices. Each device shall be identified
with an identification code corresponding to that used on the Purchase Order
Drawings and cross-referenced to the manufacturer's instruction operating
manuals and catalog cut sheets.
Single-Line and Three-line diagrams.
VFI elementary diagram.
Wiring diagrams for VFIs and auxiliary cubicles.
Elementary and wiring diagrams for the following:
a.
Control and transfer switches, including escutcheons.
b.
Electrical instruments and meters, including meter register ratios and pulse
initiators.
c.
Electric power apparatus relays, including relay ranges.
d.
Instrument transformers, including typical ratio correction and phase angle
curves for each accuracy classification.
Terminal block arrangement drawings.
Interconnection diagrams.
Nameplate schedule.
Zone 4 seismic tie-down requirements and calculations.
C.
Factory Test Reports: Submit five (5) copies of certified factory test reports on VFIs
and as per applicable ANSI C37 specifications.
D.
Coordination and Site Service Data: Provide erection drawings and complete
installation instructions for shipment, unpacking, installation, erection, adjustment,
commissioning, and operating of the equipment.
E.
Operation and Maintenance Data:
1.
Operations and Maintenance Manuals: Submit five (5) copies of operations and
maintenance manuals not less than fourteen (14) working days before shipping.
Manuals shall contain parts list, recommended spare parts list, relays, relay
characteristic curves, meters, instruments, transducer instruction books, and
operations and maintenance information for vendor supplied equipment. In
addition 11 by 17 inches (280 by 430 mm) copies of vendor drawings shall be
contained in manuals.
2.
Spare Parts List: The Vendor shall provide a recommended spare parts list and
pricing.
3.
Include maintenance instructions for cleaning methods, cleaning materials
recommended, instructions for circuit breaker removal, replacement, testing,
calibration, adjustment, and lubrication.
F.
Field quality-control test reports. Field tests specified in the cited ANSI/IEEE standards
to be performed by an independent testing agency in accordance with NETA prior to
acceptance
261313-2
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
1.4
ITSF 15000556/CD
Attachment B-7
QUALITY ASSURANCE
A.
Electrical Components, Devices, and Accessories: Listed and labeled as defined in
NFPA 70, Article 100, by a testing agency acceptable to authorities having jurisdiction,
and marked for intended use.
B.
Comply with IEEE C57.12.28, IEEE C37.74, IEEE C37.60, ANSI/IEEE 386, IEC60529,
and IEEE 592.
C.
The switch shall be tested to IEC 60529 for submersibility. The switch shall be rated
IP68 for 7 days with a 10 foot head of water.
D.
The switch manufacturer shall be ISO 9001:2008 and ISO 14001:2004 certified.
1.5
DELIVERY, STORAGE, AND HANDLING
A.
The VFIs shall be shipped preassembled at the factory. No field assembly shall be
required.
B.
The contractor, if applicable, shall handle, transfer and move the switches in
accordance with manufacturer’s recommendations.
1.6
A.
PROJECT CONDITIONS
Environmental Limitations: Rate equipment for continuous operation at indicated
ampere ratings for the following conditions:
1.
2.
3.
Ambient temperature not exceeding 122° F.
Altitude of 30 Feet above sea level.
Interrupter switches shall be submersible for vault installation.
PART 2 - PRODUCTS
2.1
A.
MANUFACTURERS
In other Part 2 articles where titles below introduce lists, the following requirements
apply to product selection:
1.
2.
Available Manufacturers: Subject to compliance with requirements,
manufacturers offering products that may be incorporated into the Work include,
but are not limited to, manufacturers specified.
Manufacturers: Subject to compliance with requirements, provide products by
one of the manufacturers specified.
261313-3
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
2.2
ITSF 15000556/CD
Attachment B-7
MANUFACTURED UNITS
A.
Description: Underground submersible switchgear shall be designed for vault wall or
floor mounting, subsurface, and tested per applicable sections of ANSI C37.71, ANSI
C37.72, and the latest version of IEC 60265 standards. Certified test reports shall be
provided.
B.
Ratings: Suitable for application in 3-phase, 3-wire, 60-Hz system.
C.
System Voltage: 12 kV nominal; 15 kV maximum.
2.3
A.
VACUUM FAULT INTERRUPTERS
Manufacturers:
1.
G&W Electric, S&C Electric, Thomas & Betts (Elastimold), or approved equal
B.
Comply with IEEE / ANSI C37.60 and C37.74. The switch shall be tested to IEC 60529
for submersibility. The switch shall be rated IP68 for 20 days with a 20 foot head of
water.
C.
PRODUCT CONSTRUCTION: Enclosure shall be NEMA 6P submersible, front access
to cables and operators, and be equipped as follows:
1.
Padlocking handle
2.
Document holder inside of enclosure door
3.
NEMA 6P submersible enclosure
4.
Viewing windows
5.
External Open/Close/ Power handles
D.
Interrupter Switches: Stationary, three phase, gang operated, and suitable for
application at maximum short-circuit rating of integrated VFI assembly.
E.
Ratings shall be as follows:
1.
Main “Bus” Rating - 600 A, continuous, aluminum, completely shielded.
2.
Maximum Design Voltage – 15kV
3.
Impulse Level (BIL) Voltage - 95kV
4.
Continuous Current, Amperes - 600
5.
Fault Interrupter rating - 16kA asymmetrical
6.
Fault Interrupter rating – 12.5kA symmetrical
7.
Mechanical Endurance (min) - 2000 Operations
8.
Bushings – 600A, all ways
F.
Design Level of Available-Source Fault Current: Integrated short-circuit rating
consistent with value of fault current indicated. Delete first paragraph below if ampere
rating is shown on Drawings.
G.
Window: All ways of the switch shall be equipped with an integral blade type air
insulated disconnect switch incorporated within the solid dielectric module to provide a
true visible break. The air insulated Visible Break switch shall be in series with the
vacuum interrupter and provide a clear three-phase visible break of the circuit. The
261313-4
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
ITSF 15000556/CD
Attachment B-7
visible break must be easily seen through a viewing window molded as an integral part
of each solid dielectric module. The use of oil or other dielectric fluids is not
acceptable.
H.
Cable Entrances: Load Break Switches shall have cable entrances tested to IEEE 386
and be, as indicated on the single line drawing, 15KV, 95KV BIL, 600A Dead break
Apparatus Bushings per IEEE 386 Figure 11. Fault interrupter cable entrances shall be
tested to IEEE 386 and be, as indicated on the single line drawing, 15KV 95KV BIL,
600A bushing well per IEEE 386 Figure 3.
I.
Power Functions and Control: Comply with applicable requirements in NEMA SG 2:
1.
Indicator: Contact position indicator with LEDs.
2.
Front mounted, hook-stick operated, manual trip and close handles.
3.
Completely submersible enclosure, including control unit.
4.
Provide SCADA ready features, including integral current transformers and
voltage transformers for control power.
J.
Electronic Controls
1.
An electronic control and protection panel shall be provided to monitor load and
fault current on all three phases of each interrupter and the status of each load
break switch.
2.
The current transformers encapsulated within the solid dielectric modules shall
provide control power and current sensing. No external power source shall be
required for overcurrent protection.
3.
Operational temperature range of the control shall be -40°C to +65°C. Maximum
time for power up and ready to trip when closing on a circuit shall be ten percent
of the trip time or 1/2 cycle, whichever is greater. Trip selection may be made
with the interrupter energized. The range of Phase Overcurrent minimum trip
settings shall be 30-600A (1000:1 CT).
4.
Switch assemblies with fault interrupters shall have high speed magnetic actuator
and shall be SCADA ready by design. Provide SEL-751A protective relay and
transformer protection, with full pushbutton interrupter control and remote
SCADA control. Transformer status and alarms shall be wired to the SEL-751A
relays.
5.
Relays and controls shall be housed in a NEMA 4X enclosure mounted adjacent
to the switch assembly. The 24V DC control shall be provided by Contractor
supplied power supply, using the VFI-generated 120V AC, as noted above.
6.
Relays and controls for switches and interrupters shall be prewired between the
control panel and the switch assembly to the extent possible. Provide one or
more cable assemblies between the control enclosure and the VFI assembly.
7.
Provide an Ethernet switch/signal converter for each switch control panel,
connecting the vacuum interrupter switch /transformer protection relays, switch
assembly status, and other controls with the fiber optic network. The Ethernet
switch shall include fiber optic network connections for the loop network
configuration, in the same NEMA 4X control enclosure.
8.
Network protocol shall be DNP3, with NTP over IP. Electronic devices shall be IP
addressable to the extent possible.
K.
Standard Components - The following shall be included as standard:
261313-5
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
1.
2.
3.
4.
5.
6.
7.
8.
9.
L.
ITSF 15000556/CD
Attachment B-7
Welded stainless steel mechanism housing painted light gray with stainless steel
and brass fasteners.
Lifting provisions
½”-13 nuts to provide sufficient grounding provisions for interrupter and all cable
entrances.
Stainless steel three line diagram and corrosion-resistant nameplates.
Switch operating handle with padlock provision.
Parking stands
Mounting bracket
Operating handle
Solid dielectric deadfront PT for control power
Factory Production Tests:
Each interrupter shall undergo the following production testing. Test reports must be
available upon request.
1.
A mechanical operation check
2.
AC hi-pot tested one minute phase-to-phase, phase-to-ground and across the
open contacts
3.
Circuit resistance shall be checked.
4.
Each solid dielectric module shall undergo an X-ray inspection and a partial
discharge test to ensure void-free construction.
5.
Primary current injection test to test CTs, trip mechanism, and control
2.4
FABRICATION
A.
The switch assembly shall be a dead-front submersible design. The operating
mechanism housing shall be stainless steel with a viewing window for verification of
vacuum interrupter contact position. The housing shall be painted ANSI 70 light gray
using corrosion-resistant epoxy paint. Operating handles shall be padlockable and
adaptable to keylock schemes. The operating shaft shall be stainless steel providing
maximum corrosion resistance. A double "O" ring shaft seal shall be used for a leak
resistant, long life seal.
B.
The SCADA control panel shall be wall mounted, NEMA 4X, preassembled devices
and wiring, with front window to view control device and protective relay status. Panel
latch handles shall be padlockable and adaptable to keylock schemes.
2.5
COMPONENTS
A.
The solid dielectric module must be coated with a semi-conductive layer of epoxy,
providing a completely dead front device. The semi-conductive layer must be tested to
IEEE 592 to ensure it can carry fault current to ground so as to ensure operator safety.
B.
The load break switch shall be designed for long term operation in the harshest
environments. The interrupter design must be tested to IEC60529 and achieve a
protection rating of IP68, subjected to a 10’ head of water pressure for 7 days.
261313-6
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
ITSF 15000556/CD
Attachment B-7
C.
A large viewing window shall permit visual verification of vacuum contact position,
either open or close. The position indicator shall be connected directly to the drive
assembly. In addition, three different color LEDs shall be provided to verify Power OK,
“open” and “close”, in addition to the flag indicator. An operation counter shall be
provided.
D.
The switch shall interrupt all load currents within the vacuum bottle. The switch shall
include two mechanical interlocks, one external and one internal, for safe operation.
E.
Load break switch mechanism shall consist of three vacuum bottle assemblies
mechanically linked to a single spring-assisted operating mechanism. Manual opening
and closing of the switch shall be via an operating handle.
2.6
A.
IDENTIFICATION
Hazard Alerting Signs
The exterior of the pad mount enclosure (if furnished) shall be provided with “Warning--Keep
Out--Hazardous Voltage Inside--Can Shock, Burn, or Cause Death” signs. Each VFI shall be
provided with a “Danger--Hazardous Voltage--Failure to Follow These Instructions Will Likely
Cause Shock, Burn, or Death” sign. The text shall further indicate that operating personnel
must know and obey the employer’s work rules, know the hazards involved, and use proper
protective equipment and tools to work on this equipment. Each VFI shall be provided with a
“Danger--Keep Away--Hazardous Voltage--Will Shock, Burn, or Cause Death” sign.
B.
Nameplates, Ratings Labels, and Connection Diagrams
Each VFI shall be provided with a nameplate indicating the manufacturer’s name, catalog
number, model number, date of manufacture, and serial number. Each VFI shall be provided
with a ratings label indicating the following: voltage rating; main bus continuous rating; shortcircuit rating; and load break switch ratings including duty-cycle fault-closing and short-time.
PART 3 - EXECUTION
3.1
INSTALLATION
A.
Ship VFI assembly complete with all anchoring and attachment bolts for wall mounting
to concrete, including factory provided galvanized channel-iron, with additional floor
galvanized channel-iron support, fully seismic rated. County personnel will attach VFI
to wall supports by drilling concrete and bolting.
B.
Ship VFI SCADA Control Panels complete with all anchoring and attachment bolts for
wall mounting to concrete, including anchor bolts for seismic rating. County personnel
will attach the protection and control assembly to the wall. Provide floor support with
galvanized channel-iron, if required.
261313-7
MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015
City and County of San Francisco
Office of Contract Administration
Purchasing
C.
3.2
ITSF 15000556/CD
Attachment B-7
Contractor shall interconnect main VFI switch components with VFI SCADA control
panel. Verify all control functions locally. Connections to transformers (power and
control) and to SCADA network (control) will be provided by others.
FIELD QUALITY CONTROL
A.
Prepare for acceptance tests as follows:
1.
Test continuity of each circuit.
2.
Primary current injection test
B.
Perform the following field tests and inspections and prepare test reports:
1.
Perform each electrical test and visual and mechanical inspection in accordance
with NETA. Certify compliance with test parameters. Perform NETA tests and
inspections for each of the following NETA categories:
a.
b.
c.
2.
3.3
Interrupters and switches.
Protective relays.
Instrument transformers.
Schedule and perform initial VFI and SCADA control panel tests before 12kV
circuit is energized. Perform final electrical tests when 12kV system is energized.
ADJUSTING
A.
Set field-adjustable, protective-relay trip characteristics according to results in
Section 260573 "Overcurrent Protective Device Coordination Study."
B.
Provide for manufacturer’s representative to witness testing, calibration, and initial
energization of switches.
C.
Provide electronic copy of all settings to Owner, including electronic program input for
each control
3.4
A.
PROTECTION
Temporary Heating: Apply temporary heat to VFI, according to manufacturer's written
instructions, throughout periods when VFI environment is not controlled for
temperature and humidity within manufacturer's stipulated service conditions.
END OF SECTION 261313
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MEDIUM VOLTAGE FAULT INTERRUPTERS
March 2015