TEE 2320252 - Caterpillar

A compensating current transformer is used in self regulated constant voltage generators with serial numbers 600 and up. These generators can come connected for any of the voltages that follow: Both voltages of a (120/208, 120/240, 200/400 or 240/480) single voltage generator can be used at the same time. On the (120-240, 200-400 or 240-480) 10 wire dual voltage generators the leads can be connected to get one or the other of the voltages, not both at the same time. Rated voltage on dual voltage generators is for a line to line connection. A line to neutral connection will give 58% of the rated voltage.
If the generator is operated at a voltage that is different than nameplate rating; you must operate with a different kW output limit. Use the formula that follows to find the kW limit for voltages other than nameplate.
I and P.F. are constant, at nameplate rating. If output voltage is changed, the three phase kW limit will change.Example: The ampere rating on the generator must not be exceeded.Three Phase Generators
120/208 Volt Generators
Saturable reactor (C) has the common tap connected to phase winding lead (t2) through regulator terminal (10). The 120V tap is connected to contact (D0), on voltage droop control switch (B), through regulator terminal (1). The generator neutral (T0) is connected to the regulator through regulator terminal (2).120/208V generators can be made to give 127/220V or 139/140V service. If the wire on the 120V tap is moved to the 127V tap, the generator will give 220V line to line and 127V line to neutral.
The KW, KVA and ampere output of the generator must be limited to less than nameplate rating to help prevent damage to the generator field windings.
To calculate the reduction necessary, use the formula that follows: If the wire on the 120V tap is moved to the 139V tap, the generator will give 240V line to line and 138V line to neutral. The output of the generator must be limited to: When a 120/208V self regulated constant voltage generator is to be operated in parallel with a 120/208V "N" or "K" series self regulated saturated field generator, the saturable reactor must be connected to use the common and 127V taps. Make a mark (show new location) on the nameplate of the generator when reactor taps are changed from the original location.
120/208 VOLT GENERATOR CONNECTION A. Voltage droop transformer.B. Voltage droop control switch.C. Saturable reactor.D. Full wave rectifier.E. Generator armature (stator).F. Generator field (rotor).G. Exciter armature.H.