Architectural and Engineering Design Standards

7) Low battery voltage.

8) High battery voltage.

9) Low fuel supply.

As an alternate to the Base Bid, the vendor shall provide monitoring of the compressed

air storage tanks for low air pressure in lieu of low and high battery voltage.

l. Sub-Base

The engine generator unit shall be mounted on a full sub-base fabricated of structural

steel with heavy cross members suitable for lifting. Spring type vibration isolators of

the type and quality recommended by the manufacturer shall be supplied. Mounting

holes for the isolators shall be located in the sub-base by the engine manufacturer to

insure equal distribution of weight on the isolators. Maximum vibration transmission

not to exceed 6%.

All service connections, fuel, water, electric, etc. to the engine shall be through

flexible connection devices. Vendor shall supply the flexible connection devices.

m. Alternator & Exciter

1) The alternator shall maintain continuously its specified fully derated output at 0.8

power factor under the worst conditions stated in these specifications without

exceeding 130° C temperature rise over listed engine room maximum ambient

temperature.

2) The windings of the alternator and exciter shall be insulated with Class F

insulation suited for high humidity environment.

3) The exciter shall be brushless direct connected type with shaft mounted diodes and

built-in permanent magnets eliminating field flashing.

n. Alternator

The alternator shall be a multi-pole revolving field type with rotating brushless exciter

and solid state regulator. The number of poles shall be compatible with 1200 or 1800

rpm to provide a 60 Hertz output. The alternator shall be directly connected to the

engine flywheel housing and driven by means of a multiple disc coupling from the

flywheel. Voltage regulator shall be SCR static type with voltage adjustment rheostat

and automatic subsynchronous speed protection. Voltage regulation shall be within

±1% of rated voltage, from no load to full load. The transient voltage dip shall not be

greater than 25% of rated voltage when full load at rated power factor is applied to the

alternator.

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November 1, 2016