bare copper grounding cable entering the enclosure from the bottom.
d.
One current transformer conforming to the requirements of
paragraph INSTRUMENT TRANSFORMERS shall be provided and housed in
the resistor enclosure. The current transformer shall have the
ratio shown and be connected as indicated to the associated
overcurrent relay, device 51G, located in the [metal-clad
switchgear] [instrument and relay cabinet specified above]. The
terminals of the current transformer shall be wired with not less
than No. 10 AWG conductors to the proper terminals of device 51G
through a short-circuiting type of terminal block [and test block]
located in the [metal-clad switchgear] [instrument and relay
cabinet] [transformer terminal cabinet].
2.6.1.4
Load-Tap-Changing Equipment
**************************************************************************
NOTE: The application will determine whether
load-tap-changers will be paralleled. System
configuration may require reverse power flow
equipment. Specify only when required.
**************************************************************************
Load-tap-changing equipment shall be provided to provide automatic
adjustment of a transformer's low-voltage winding voltage. In addition to
the basic load-tap-changing equipment requirements listed in ANSI C57.12.10,
the load-tap-changing equipment shall include the following:
a.
A light wired in series with the control cabinet door-actuated
switch, so that the light is energized only when the door or doors
are open.
b.
A heater continuously energized to prevent condensation within the
control cabinet over ambient temperature ranges from [minus 29]
[_____] to [40] [_____] degrees C [minus 20] [_____] to [104]
[_____] degrees F, with both the heater and thermostat contact
wired in series with the control cabinet door-actuated switch, so
that the heater is de-energized when doors are open.
High-temperature thermal protection shall be included.
c.
One-pole or two-pole thermal-magnetic molded-case circuit breakers
suitable for the control voltage, when required by the
manufacturer, and for low-voltage alternating-current power to
control devices, motor, heater, and light circuits.
d.
Terminal blocks wired for proper interconnection with remote items
of equipment.
e.
Circulating-current equipment necessary to allow parallel
operation of the transformer.
f.
Reverse power flow equipment wired so that the load-tap-changer
functions only when electric power flows from high-voltage to
low-voltage windings in the transformer.
2.6.1.5
Bushings and Equipment Connection Provisions
**************************************************************************
NOTE: A power transformer will require bushings and
SECTION 16311A
Page 36
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