2.6.8.2
External Connections
**************************************************************************
NOTE: For NEMA 3R enclosures power cables shall
enter from the bottom.
**************************************************************************
Power and control cables will enter the control centers at the [bottom]
[top] [where shown on the drawings]. [Where power and control entry points
are not shown, and terminal blocks are not given on the drawings, the
Government will furnish this information to the Contractor after award of
contract.]
2.6.8.3
Terminal Blocks
Terminal blocks shall meet the requirements of paragraph TERMINAL BLOCKS
above. In no case shall the terminals provided for circuit breakers or
contactors accommodate less than the number or size of conductors shown on
the drawings. Special attention shall be given to wiring and terminal
arrangement on the terminal blocks to permit the individual conductors of
each external cable to be terminated on adjacent terminal points.
2.6.9
[Control Transformers
**************************************************************************
NOTE: Delete when individual control transformers
are specified or external control circuit is
provided.
**************************************************************************
Control transformers for several starter units shall be mounted in a
separate compartment and its primary windings shall be connected to the
main bus through a molded case circuit breaker of suitable rating. The
control transformers shall be rated 480-120 volts and shall conform to the
requirements for control transformers in NEMA ST 1. Control transformers
shall have adequate volt-ampere capacity for the control functions
indicated and an additional 10 percent capacity. Transformers shall be
installed without primary fuses. Except as otherwise indicated on the
drawings, each unit compartment shall provide a fuse for control power in
one secondary lead and shall have the other secondary lead grounded. The
unit disconnect shall be equipped with a normally open contact to isolate
the control circuit from the source when the controller disconnect is open.]
2.6.10
Accessories and Control Devices
**************************************************************************
NOTE: Retain only paragraphs for accessories
actually used for a given procurement.
**************************************************************************
Control accessories shall be provided, and shall be suitable for mounting
on the front of, or inside, the control centers as indicated on the
drawings. Control accessories shall meet the applicable requirements of
NEMA ICS 2. Relays and other equipment shall be so mounted that mechanical
vibration will not cause false operation.
2.6.10.1
Control Stations
Push-button stations and selector switches shall conform to NEMA ICS 2,
SECTION 16403A
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