S&C Instruction Sheet 663-500 15
Installation
WARNING
Low-voltage wiring routed inside the pad-mounted
gear enclosure must be a minimum of 6 inches
(152 mm) at 14 .4 kV and 7½ inches (191 mm) at
25 kV away from components that will be energized
at high voltage . Do not place wiring where it might
fall onto a component that will be energized at high
voltage, such as the bus, or where it will be in the
way of moving parts .
Failure to maintain proper clearance can result in a
flashover, injury, and equipment damage .
NOTICE
Openings made into the low-voltage control
compartment must be sealed with a suitable
compound to prevent the entry of moisture or
animals . Failure to properly seal the openings can
result in damage to the electronic components .
NOTICE
Do not install the current sensors on unshielded
cables or on cables where the insulation is exposed
but ungrounded (for example, where dielectric tape
or heatshrink tubing is used) . These current sensors
are intended for application at ground potential and
can be damaged by the voltage gradient between
the cable insulation and ground .
NOTICE
Twelve current sensors are required for source-
transfer pad-mounted gear furnished with optional
switch-terminal adapters (catalog number suffix
“-M1”) that permit two cables per phase . Install
the current sensors in accordance with the wiring
diagram provided .
The automatic source-transfer scheme will not
operate properly when only six current sensors are
installed .
S&C Current Sensors
STEP 7.
Six S&C Current Sensors (packed separately)
are provided for units furnished with the
optional
Overcurrent Lockout
feature
(catalog number suffi x “-Y2”). The leads from
the current sensors in each switch compartment
must be connected to a terminal block located
in the associated terminal-block compartment,
behind the bolted panel labeled “Terminal
Blocks.” See Figure 9.
The bottom plate in each terminal-block
compartment is removable to facilitate drill-
ing an entrance hole for the lead wires. When
conduit is not used, protect the lead wires from
abrasion against the knockout opening with
a rubber grommet or by taping. Then, apply a
suitable compound to fill the space between the
lead wires and the opening to prevent entry of
moisture or animals.
Figure 9. The left side of the low-voltage control compartment
showing the left terminal-block compartment (the right
terminal-block compartment is similar) for connection of
leads from S&C Current Sensors furnished with the optional
Overcurrent Lockout feature (option suffix “-Y2”); and for
customer connections when optional auxiliary switches (suffix
“-C9” or “C10”), the Remote Indication feature (option suffix
“-Y4”), or the Supervisory Control feature (option suffix “-Y6”)
is furnished. Terminal blocks for options “-Y4” and “-Y6” are in
the left terminal-block compartment only.
Termination-block
compartment
