Transmittal of generator prepurchase specifications, March 1998

NYC 9/11 Public Portal Document

PPS-Generators

Running White Color J On Line White Color Lockout Red Color

Spare lights, shall be provided for a total of twenty-four (24).

The indications shall be of the manual reset type. An alarm silencing switch and "alarm silenced" pilot light shall be included.

Provide form C (n/o-n/c). contacts for each of the above pre-alarms and shutdowns for interface with the BMS system. Extend wiring out to a set of terminals dedicated for this interface for the BMS contractor to connect to.

B. The generator power and control switchgear shall be of the free-standing, deadfront, totally metally enclosed, externally operable type, conforming to N.E.M.A. Class III switchboard construction, consisting of an assembly of standardized vertical sections, each having rigid frame construction of heavy gauge formed steel, including bottom closer plate, rustproofed, primed and painted to provide an overall even appearance. Include a 12" horizontal separation between “service" disconnected feeder devices (circuit breakers). The switchgear shall conform to the following :-

1. No current carrying parts shall be within 12" of the finished floor.

2. It shall have complete phase leg bussing, suitably braced and suitable for the voltage applied. It shall also have a half size neutral bus which shall extend the same len^ as the phase leg bussing. A 3" x copper (base bid) or 4" x ’A" aluminum (deduct alternate) ground bus shall extend for the entire length of the switchboard. The neutral bus shall be bonded to the ground bus by means of (2) 500 MCM insulated copper cables. Bussing indicated as main, including connection to generator circuit breakers, shall be, per phase, as follows:-

a. Main bussing designated with an ampere rating shall be sized based on a rating of 1000 amps per square inch of copper (base bid) or 750 amps per square inch of aluminum (deduct alternate). Where the sum of the generator circuit breaker trip sizes exceeds the indicated ampere designation for the main bus, the rating of the main bus shall be increased, for its entire length to the sum of the generator circuit breaker trip sizes, unless divergent load paths reduce the load requirements. In such case, the divergent sections of bus ("A" and "B") shall total 125% of generator breaker trip ratings, and the rating of each section shall be calculated as:-

OEM PPS-29 Generators 7 WTC March 20, 1998

NYC-WTC_000166904