Electrical Connections
31
Figure 26.
Typical Cable Termination Compartments (Unit on
left has top breaker cables exiting top, and bottom breaker
cables exiting top through “chimney” or trough. Unit on right
has top breaker cables exiting top and bottom breaker cables
exiting bottom.)
Secondary Control Wiring
Secondary control wiring is carefully installed and tested at the
factory. Inter-group wiring at shipping splits can be readily con-
nected by referring to wire markings. These wires are not ter-
minated and are of sufficient length to be routed to their
termination point after cubicles are bolted together. Terminals
for these leads are furnished by the purchaser to suit the available
crimping tools. Terminal block hardware is furnished with the
switchgear. All wiring diagrams needed for installation are
furnished in advance.
Wires can be easily traced on wiring diagrams furnished for
the switchgear. Each device is illustrated and identified with an
alphanumeric code. Each terminal on each device is identified
by a number. The wire list adjacent to each device on the dia-
gram indicates the device and terminal number to which each
wire is connected at the next connection point.
All secondary control wiring installed by the factory is neatly
bundled and cleated to the cubicle side plate. Make all field
connections in a similar manner. Check that the circuit breaker,
its components, and the hinged front panel clear any additional
wiring installed.
Figure 27
shows a typical secondary control
cable installation. All purchaser wiring is to be routed behind
the cable retainer which is removable for installation purposes.
Use plastic or nylon ties to secure all field installed wires to
the cubicle structure.
Figure 27.
Secondary Control Cable Connections
Ground Connections
A common ground bus is incorporated in all units for properly
grounding the equipment after installation.
The ground bus extending through the switchgear is accessible
in the primary cable area of each unit. The interunit connector
has provisions for two bolts at each end. For ease of assembly,
install bottom bolts first. Insure that ground bar to circuit breaker
cell is also bolted to interunit bar, as shown in
Figure 28
.
Provision for connecting this ground bus must be made in such a
manner that a reliable ground connection is obtained. Consult
latest National Electrical Code for ground connection standards.
Figure 28.
Ground Bus Connection
Temporary Ground Connections
It is recommended that no work be done on current carrying
parts until these parts have been disconnected from the system
and solidly grounded. One method of solidly grounding the
high voltage circuit is by use of a grounding device. This
device is placed in a cubicle in the same manner as a breaker
and provides a path to ground. It is furnished only when specified
in the contract.
0.25" X 2.00" (6 X 51mm) COPPER
GROUND BAR
REAR OF UNIT
GROUND BAR TO CABLE AREA
PLAN VIEW
INTERUNIT GROUND CONNECTOR
SHEET FRONT
CUBICLE SIDE
BREAKER CELL
CONNECTOR TO CIRCUIT
FRONT OF UNIT
0.1
0.5
0.18
0.12
0.0
0.0
0.13
0.1
0.05
6.06
4.34
4.05
6.72
2.05
4.70
CENTER
1.0" (25mm) MAXIMUM
FLOOR LINE
CONDUIT
SEAL
CONTROL CABLE
TERMINAL BLOCK
01746-95
