Transmittal of generator prepurchase specifications, March 1998

NYC 9/11 Public Portal Document

PPS-Generators

2.08 GENERATOR POWER AND CONTROL SWITCHGEAR

A. The generator power and control switchgear shall incorporate a cubicle for each engine­ generator set, plus future, a master cubicle, and cubicles containing outgoing feeder circuit breakers as indicated elsewhere.

The generator power and control switchgear shall incorporate the following features and functions

1. In response to the activation of voltage sensing relays in the control switchgear via circuitry runs from automatic transfer switches (as described elsewhere), controls within the switchgear shall automatically initiate engine cranking, as described hereinbefore, for each of the generator sets connected to the switchgear. The generator sets shall each be automatically brought up to stable operating conditions.

2. The first set to reach 90% of nominal voltage and frequency shall be automatically connected to the switchgear bus by electrically closing its circuit breaker. As successive sets reach stable conditions, they shall each be automatically syn­ chronized and paralleled with the generator sets already connected to the switchgear bus.

3. Load shall be picked up in stages and applied to the switchgear bus automatically by electrically closing the outgoing feeder breakers in the switchgear in a pre­ determined sequence. The sequence shall be such as to avoid overloading of the generators during the synchronizing process, and shall be manually adjustable in the field. Failure of any set to start shall cause lock-out of all loads beyond the capacity of the remaining sets.

4. Switchgear control and instrumentation shall comply with previously specified requirements for the accommodation of non-linear (i.e., harmonic-producing) loads.

5. As load is applied to, or removed from, the switchgear bus, generator set control in the switchgear shall automatically divide the load so that it is equally shared between the sets.

6. Shutdown of any generator set which had been connected to the switchgear bus shall automatically cause load to be "dumped" by opening outgoing feeder breakers in the switchgear in a pre-determined, field adjustable sequence as necessary to avoid over-loading of the remaining sets.

OEM PPS-25 Generators 7 WTC March 20, 1998

NYC-WTC_000166900