A.B. Chance Company
AIS Padmounted Switchgear
SPECIFICATIONS
I. General
1. The deadfront design padmounted switchgear shall be in accordance with the drawings and
one-line diagrams provided by the user and shall conform to these specifications.
2. Submittals
When requested, the manufacturer of the padmounted switchgear shall furnish the following
drawings and reports:
a)
Layout showing dimensions, arrangements, and weights.
b)
Certified test reports of similar manufactured units showing current carrying and load interrupting capability of switches and complete padmounted equipment assembly based
on maximum design voltage.
3. Compliance with Standards and Codes
The padmounted gear shall meet as a minimum the applicable requirements of the following
standards and codes:
a)
Article 710-21(e) in the 1990 National Electrical Code, which specifies that the interrupter
switches in combination with power fuses shall safely withstand the effect of closing,
carrying, and interrupting all possible currents up to the assigned maximum short circuit
rating.
b)
All portions of current ANSI, IEEE, and NEMA standards applicable to the basic switch
and fuse components.
4. Ratings
Voltage, Nominal
Voltage, Maximum Design
Voltage, BIL
15kV
15.5kV
95kV
25kV
27kV
125kV
Main Bus Continuous Current
600 Amp
600 Amp
Three-Pole Interrupter Switches
Continuous Current
Load Interrupting Current
Cable Charging Current
Magnetizing Current
600 Amp
600 Amp
10 Amp
21 Amp
600 Amp
600 Amp
15 Amp
21 Amp
Short Circuit Ratings
Momentary Current
®
POWER SYSTEMS, INC.
12,000 Amp, RMS, Symmetrical
19,200 Amp, RMS, Asymmetrical
Because Hubbell has a policy of continuous product improvement, we reserve the right to change design
and specifications without notice.
210 N. Allen, Centralia, MO 65240 USA
Bulletin 17-9102
Telephone: 573/682-8414
Revised August, 2006 ©Copyright 2006 Hubbell, Inc.
Email: hpsliterature@hps.hubbell.com
Fax: 573/682-8660
Printed in USA
II. Construction
1. Enclosure
1.1 The outdoor padmounted switchgear shall consist of a single, self-supporting enclosure
of unitized construction to maximize strength, minimize weight, and inhibit internal corrosion.
1.2 In establishing the requirements for the enclosure design, consideration shall be given to
all relevant factors such as controlled access, tamper resistance, corrosion resistance,
and resistance to entry of foliage, animals, and airborne contaminants. The enclosure
shall meet the latest revision of ANSI C57.12.28 - 1988 “Padmounted Equipment Enclosure
Integrity,” except the test values shall be increased to the following levels:
Inward Axial Force - 50 lb.
Prying Leverage Test - 75 lb.
Pull Test - 150 lb.
Probing Wire - 14 AWG solid soft drawn copper-10 feet long
1.3
The basic material shall be a minimum of 10-gauge, low carbon, hot-rolled steel, pickled
and oiled sheet for all structural (side) panels.
1.4
All structural joints and butt joints shall be welded, and the external seams shall be ground
flush and smooth. The welding process shall be one that eliminates alkaline residues and
minimizes distortion and spatter.
1.5
The base of the enclosure shall have a minimum 11/2 inch flange around the entire bottom
to facilitate cleat clamping.
1.6
The door openings of the enclosure shall have 90-degree flanges, facing outward, that
shall provide strength and rigidity as well as overlapping between doors and door openings to guard against undesired entry.
1.7
The roof of the enclosure shall be constructed of 12-gauge, low carbon, hot-rolled steel,
pickled and oiled sheet and be welded on to maximize strength and prevent entry of water,
airborne contaminants, and other foreign objects.
1.8
The inside surface of the center compartment shall have a coating of “no drip” compound.
1.9
The roof of the padmounted enclosure shall be crowned a minimum of one inch to prevent
standing water.
1.10 All hinges, hinge pins, and permanent lifting provisions shall be stainless steel. All permanent lifting provisions shall be blind tapped. Removable lifting tabs shall be provided.
1.11 The bottom panel of the center compartment shall be constructed of 18-gauge galvannealed steel. The bottom panel shall have an adequate number of screened drains to
allow drainage from the tank and provide ventilation, but prohibit the entrance of animals
and/or foliage. Drains shall be a minimum of 11/2 inches in diameter. All holes in the floor
are to be punched or drilled (no flame cutting is permissible).
1.12 No vents are permitted on top or sides of enclosure, thus eliminating “chimney effect” of
gases and contaminants in switch pad vault.
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2. Exterior Doors
2.1
Doors shall be constructed of 13-gauge, low carbon, hot-rolled steel, pickled and oiled
sheet.
2.2
Door openings shall have 90-degree flanges to provide strength and rigidity as well as
deep overlapping between doors and door openings to guard against water entry and
conform to ANSI C57.12.28 “Padmounted Equipment Enclosure Integrity.”
2.3
Doors shall have a minimum of two stainless steel hinges and hinge pins. These hinges
must be bolted — not welded — to allow for easy door replacement and adjustment should
pad settling take place.
2.4
Doors shall be hinged at the sides to swing open. Doors hinged at the top are not permissible.
2.5
Each door or set of double doors shall be provided with a three-point latching system which
latches at the top, bottom and side. The three-point latching system shall be activated
with a stainless steel pentahead bolt.
2.6
Doors providing access to fused ways shall have an 18-gauge galvannealed steel storage
pocket mounted to the door for storing protective devices.
2.7
Each door shall be equipped with a door retainer which will allow the door to open 105
degrees.
2.8
No automatic latching doors will be permitted. Doors must be manually latched to prevent
the possibility of door closing and trapping any loose clothing or human extremities in the
latched door.
3. Exterior Finish
3.1
The padmounted switchgear enclosure shall be cleaned in an alkali cleaner and water
bath before primer is applied.
3.2
The primer shall be zinc-rich to provide cathodic protection for surface scratches, and
applied to an average dry thickness sufficient to meet applicable performance standards.
3.3
The top coat of paint shall be a water-base acrylic. The top coat shall be applied to an
average dry thickness sufficient to meet applicable performance standards.
3.4
The unit shall be painted Munsell, 7GY 3.29/1.5, green.
3.5
The unit shall be placed in a low temperature oven to properly dry.
3.6
The finishing system shall conform to the following tests per ANSI C57.12.28 “Padmounted
Equipment Enclosure Integrity” (Formerly the Edison Electric Institute Guidelines):
a. 1,500 hour salt spray test per ASTMB-117.
b. Crosshatch adhesion test per ASTMD-3359.
c. 1,000 hour 98 percent humidity test per ASTMD-2247.
d. 160 inch-pound falling dart impact test per ASTMD-2794.
e. 72-hour mineral oil resistance test.
f. 500-hour accelerated weather test per ASTMG-53.
g. 3,000 cycle abrasion test per ASTMD-4060.
-3-
3.7
The padmounted switchgear assembly finish shall be designed such that it shall be possible to field repair (with the paint as applied at the factory) any minor abrasions to the
finish.
III.Components
1. Interrupter Switches
1.1
Interrupter switches shall be rated for continuous and load interrupting capability per ANSI
C37.72-1987. The insulating medium shall be air.
1.2
Interrupter switches shall utilize a quick-make, quick-break spring-loaded mechanism.
The mechanism shall swiftly and positively open and close the interrupter switches independent of the speed of the switch operator.
1.3
Interrupter switches shall be operated by means of an externally-accessible switch operating hub. The operating hub shall be located inside a recessed pocket with padlocking provisions. The recessed pocket shall be padlockable with the interrupter switch in
either the open or closed position. The recessed pocket shall house a switching handle.
The operating hub shall include “open” and “closed” labels to indicate interrupter switch
positions.
1.4
Interrupter switches shall be provided with contact blades and interrupters for circuit
closing, including inadvertent fault closing, continuous current carrying and circuit interrupting.
5.5
the interrupuer wwitches shall have a visible open gap to allow visual verification of the
open and closed switch positions. A polycarbonate clear window with minimum dimensions 13.5" x 31.5" shall be supplied to provide visual verification of switch position and
maintain deadfront integrity. The window shall be removable to allow maintenance without
disassembling the enclosure.
2. Transfer Bus Support Insulators
2.1
Transfer Bus Support Insulators shall conform to the following minimum requirements:
Electrical Requirements
15kV
25kV
Impulse Withstand....................................................................................95kV
Leakage Distance.......................................................................... 10.5 inches
Dry Arcing Distance......................................................................... 6.0 inches
Impulse Critical Position.........................................................................105kV
60 Hertz Wet Withstand............................................................................30kV
150kV
24.0 inches
9.5 inches
170kV
60kV
Mechanical Requirements
Cantilever............................................................................................ 1,200 lb.
Tension................................................................................................ 5,000 lb.
Torsion............................................................................................ 3,000 in. lb.
Compression....................................................................................... 5,000 lb.
-4-
800 lb.
5,000 lb.
3,000 in. lb.
5,000 lb.
3. Bus Work
3.1
All transfer bus work shall be constructed of a minimum 3/8-inch thick aluminum alloy
6101-T61.
3.2
All transfer bus work shall consist of continuous, one-piece sections of aluminum bar.
Flexible braid or cable shall not be used.
3.3
Bus work and connections shall withstand the stresses associated with short-circuit currents within the rating of the switchgear.
3.4
Bolted transfer bus connection shall be made with non-corrosive bolts and with two flat
washers and one Belleville spring washer. Bolts shall be tightened to appropriate torque
to assure proper electrical contact.
3.5
Bus work shall be constructed such that the phase orientation shall be A-B-C C-B-A.
4. Ground Pads
4.1
A ground-connection pad with a short circuit rating equal to that of the switchgear shall
be provided in each termination compartment.
4.2
Ground pads shall be constructed of type 304 stainless steel and shall be 1/4 inches thick.
5. Bushings and Wells
5.1
Bushings and bushing wells shall conform to the latest revisions of ANSI/IEEE 386.
5.2
The semiconductive coating on bushings and bushing wells shall be solidly grounded to
the enclosure.
5.3
All electrical connections on bushings and bushing wells shall be made on electrolytic
tough pitch copper (C110) per ASTMB-187.
5.4
All 600 Amp rated bushings shall be provided with a retaining ring constructed of aluminum
alloy #8 with T51 temper.
5.5
All 200 Amp rated bushing wells shall be provided with a retaining ring constructed of
plated steel.
5.6
The interrupter switch bushings shall be designed such that it shall be possible to change
out a bushing in the field without disassembling the enclosure.
6. Termination Cable Compartments
6.1
Termination compartments shall house bushings and bushing wells. The bushings and
bushing wells shall be mounted on the interior walls at the minimum height of 33 inches
above the enclosure base.
6.2
Termination compartments for 600 ampere continuous rated bushings shall be of adequate
depth to accommodate encapsulated surge arresters or grounding elbows mounted on
600 ampere elbows having 200 ampere interfaces without extending the enclosure.
-5-
6.3
Termination compartments for bushing wells rated 200 amperes continuous shall be of an
adequate depth to accommodate 200 ampere loadbreak elbows mounted on insulated
parking bushings without extending the enclosure.
6.4
Termination compartments shall be provided with one 14-gauge stainless steel parking
stand for each bushing or bushing well.
6.5
Parking stands shall have a minimum distance between each other of 91/2 inches on the
source side and 111/2 inches on the tap side.
7. Fuse Doors
7.1
Each fuse door shall not allow access to the fuse until the following procedure is followed:
a)
Disconnect the appropriate elbow for the fuse and move it to the parking stand.
b)
Actuate a mechanical interlock to unlock the fuse door panel. It shall not be possible to disengage this interlock until the elbow is disconnected.
c)
Unlatch and then open the fuse door to isolate, with a visible break, then the fuse
may be easily removed.
7.2
The opening into the enclosure shall be covered when the fuse door is both open and
closed to prohibit entry by airborne contamination.
7.3
Each fuse door shall have provisions to latch so that changing fuses with a grip-all clampstick shall not cause movement of the fuse door while in the open position.
7.4
When in the open (re-fusing) position, the fuse-to-switch connection shall be visibly open.
The fuse door shall in no way be penetrating the switching enclosure, thus eliminating any
possible electrical path from internal energized parts to the fuse being replaced.
8. Fuse Mountings
8.1
The padmounted switchgear shall have options for one of the following specified fuse
mounts:
a)
A. B. Chance Padmount Electronic Sectionalizer (35-200A)
b)
S&C SM-20 power fusing (Maximum 200A)
c)
S&C SM-4Z power fusing (Maximum 200A)
8.2
d)
Cooper NX current limiting fusing (Maximum 100A)
e)
Kearney Q current limiting fusing (Maximum 125A)
The fuse doors and the padmounted switchgear enclosure shall be designed such that it
shall be possible to change out a fuse door in the field. It shall also be possible to change
the type of fuse mountings desired in the field without taking an outage on the switch’s
source or taps (other than the specific single phase tap being serviced).
-6-
IV.Labeling
1. Warning and Danger Labels
1.1
1.2
The following vinyl adhesive labels will be attached to the padmounted switchgear:
a)
A label stating the type of fuse mounting in the padmounted switchgear shall be attached to each fuse door.
b)
A label stating “DANGER-HIGH VOLTAGE BEHIND PANEL” will be attached to each
fuse door barrier.
c)
A warning label with fuse removal/installation instructions shall be attached to the
inside of latching compartment doors that open to fuse panels.
d)
A NEMA “MR. OUCH” danger label shall be attached to the inside of all latching compartment doors.
e)
An authorized persons warning labels shall be attached to the inside of all latching
compartment doors.
f)
A door latching warning label shall be attached to the inside of latching compartment
doors.
g)
A, B or C labels shall be attached above each bushing or bushing well corresponding
to the appropriate phase.
In order to maintain the integrity of the finish, there shall be no external labels or markings
on the padmounted switchgear.
2. Nameplates and Schematics
2.1
A stainless steel nameplate shall be attached on the source side panel. The nameplate
shall contain the following information.
*
*
*
*
*
*
*
*
*
*
*
2.2
A vinyl adhesive label showing the three line wiring schematic shall be attached to the
source panel and the tap panel.
Name of the manufacturer
Manufacturer’s catalog number
Manufacturer’s model number
Date of manufacture (month and year)
Serial number
Type of fuse mountings
Weight (pounds)
Maximum voltage (kV and BIL)
Continuous current rating (amperes)
Load interrupting rating (amperes)
Momentary/making current rating (KA-ASYM)
-7-
®
Because Hubbell has a policy of continuous product improvement, we reserve the right to change design
and specifications without notice.
POWER SYSTEMS, INC.
Bulletin 17-9102
Revised August, 2006
210 N. Allen, Centralia, MO 65240 USA
Telephone: 573/682-8414
©
Copyright 2006 Hubbell, Inc.
Email: hpsliterature@hps.hubbell.com
Fax: 573/682-8660
Printed in USA