GE Industrial Solutions AKD-20 Low Voltage Switchgear - Manuel (Page 43)

AKD-20 Low Voltage Switchgear
Chapter 4. Equipment Installation
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Equipment
Depth “A”
Direction
of Leads B
60” Below 19
Above 24
67” Below 26
Above 31
74” Below 33
Above 38
Table 4.23 Floor Plan
Power Cable Connections
Connect the main cables to the main lugs. Before any main
cable connections are made, the cables should be identified to
indicate their phase relationship with the equipment. Adequate
electrical and mechanical clearances must be provided between
conduit, cables, and bus. Where the cables enter the section,
they can be lashed to optional cable supports at the rear of the
cable compartment as required.
Mechanical cable terminals are normally included with the
switchgear (compression terminals are supplied when ordered)
and are mounted at the ends of the breaker runbacks in the
cable compartment. Carefully follow the cable manufacturer's
recommendations for installation of cable.
Install the cables in the proper path to the terminals, using
temporary lashing if required. Cut the cables to the proper
length. Strip the insulation to the desired dimension, being
careful not to damage any strands.
For copper cables, coat the wires with GE lubricating grease
D6A15A2, insert the cables into the terminals, and tighten the
set screws in accordance with torque values shown in the
torque value table for cable terminals in the addendum of this
manual. See Appendix A, Table A-3.
For aluminum cables, wire brush the wire strands thoroughly.
Immediately after wire brushing, coat the cable strands with a
quality oxide inhibiting compound such as Penetrox A. Insert
exposed wires into the terminals and tighten the set screws in
accordance with values shown in the torque Table A-3 in
Appendix A of this Instruction Book
.
CAUTION: The torque values shown in the table are for dry
threads only. Do not grease or otherwise lubricate the
threads on the cable terminals as this will permit over-
tightening of the screw and possible damage to the terminal
or cable.
ATTENTION: Les valeurs de couple indiquées dans le tableau
ne sont valables que pour des filets secs uniquement. Il ne
faut pas graisser ou librifier autrement les filets des câbles
terminaux, car cela produira un serrage excessif de la vis et
possiblement des dommages au terminal ou au câble.
This should result in the oozing of compound material from
between individual strands. Wipe off any excess compound.
Bolt the cable terminal connectors to the ends of the bars in the
cable compartment. A non-oxidizing grease, such as GE
lubricating grease D6A15A2 furnished with each equipment,
should be used at these connection surfaces. The bolts should
be tightened in accordance with values shown in the torque
Table A-3 in Appendix A of this Instruction Book
Lash the cables securely to the cable support, if present, to take
their weight off the runbacks and to brace them against short
circuit forces in the event of a fault.
Fig. 4-24. Typical cable lashing
The cable supports in fig. 4-24 can be optionally ordered from
the factory. The following instructions for cable lashing should
be used as a guide. Run and bend the main cable in a most
convenient orientation, making sure the main cable has been
located directly up against any cable braces (if present) before it
connects to the main cable terminals. Using a 3/8 inch diameter
continuous nylon rope or equivalent (minimum 2000 pounds
tensile strength) at 6 inches from the main cable terminals,
make five revolutions around the "A" and "B" phase main cables,
making sure the rope does not overlap. Make five revolutions
around the "B" and "C" phase main cables. With the remaining
rope, wrap around the main cable lashing between the "B" and
"C" phase and the cable brace (if present) with a minimum of 5
revolutions getting as much revolutions as possible between the
phases. Continue wrapping between the "A" and "B" phase
around the main cable lashing and the cable brace (if present)
with a minimum of 5 revolutions getting as much revolutions as
possible between the phases. Securely tie off the remaining
rope. Repeat this lashing at every 6-inch interval.
Relays and Control Devices
Remove all blocking on relays and devices as shown in the
instructions accompanying the devices.
Nylon rope – 3/8
inch (9.5 mm)
diameter.
Minimum of 5
wraps
6 inches
(152 mm)