Transmittal of generator prepurchase specifications, March 1998

NYC 9/11 Public Portal Document

PPS-Generators

C. Submit manufacturers certification attesting to the fact that the withstand rating of each transfer switch equal^or exceeds the interrupting capacity of the upstream protective device, or the available fault current if less than the interrupting capacity of the upstream device.

D. Basic features required for each transfer switch are as follows

1. It shall be of the 3-pole type when interposed in a 3-wire feeder, and of the 4-pole type when interposed in a 4-wire feeder, regardless of any other indications to the contrary.

2. It shall be of the mechanically held, mechanically and electrically interlocked type which excludes any possibility of paralleling the normal and emergency sources.

3. Each switch shall have a neutral position (i.e., load disconnect-for an adjustable time from 0 to 10 seconds-from both normal and emergency sources) to which it can be thrown during transfer and retransfer (by its electric controls) or in the "test" mode. In lieu of a neutral position, "in-phase monitoring" control of transfer and retransfer will be acceptable.

4. It shall be in N.E.M.A. Class I enclosure.

5. All components and connections within the enclosure shall be located so as noi to require rear access.

6. It shall have a 1 % accuracy 4" ampmeter, mounted on the front with ampmeter selection switch to measure load current in each phase and neutral. Ampmeter ranges shall be specific for each switch size neutral position shall be only provided in 30/4w feeders.

E. Except as noted below the automatic control features of each transfer switch shall:-

1. Be such as to transfer the load from the normal to the emergency source as soon as "stable operation" voltage and frequency conditions (within the tolerances specified elsewhere for the associated emergency generating sets) is sensed at the emergency terminals of the transfer switch.

Transfer controls shall incorporate a feature which provides an adjustable time delay from 0 to 30 seconds between the sensing of stable conditions and the initiation of transfer.

OEM PPS-45 Generators 7 WTC March 20, 1998

NYC-WTC_000166920