CAP-BEARING 3833364 - Caterpillar

Damage to the generator is possible. Do NOT exceed the rated ampere load on any single generator.
Make the final adjustments after the generators that are parallel have been running at full load for one hour. Tighten the locknuts on all controls. Install the access cover. The last condition of "Initial Start-Up" has been met. Starting Multiple Units
Refer to Operation Section, "Single Unit Operation".Paralleling Multiple Units
Units may be paralleled at no load or units may be paralleled with units under load. After the initial conditions for start-up are satisfied, verify for the following requirements.
One of the governors can be an isochronous governor. Electronic load sharing governors are an exception.
Generators must have voltage droop compensation or cross current compensation.
Start the unit which will be paralleled.
Turn on the synchronizer lights.
After the engine has run a few minutes, bring the engine up to synchronous speed. Synchronous speed means that the frequency of the incoming unit will have the same frequency of the unit that is on-line. The synchronizing lights will begin to blink. Note: The frequency of the incoming unit should be slightly greater than the line frequency. This will allow the incoming unit to assume part of the load.
Adjust the engine speed until the lights blink very slowly.
The lights turn off when the voltages of the two units are in-phase. At this point, very quickly close the breaker while the lights are out.
Use governor controls in order to share kW load between engines.
Generator temperature will be stabilized in approximately four hours. After the generator temperature has been stabilized, adjust the voltage droop rheostat of each generator in order to share the reactive load. Adjust the voltage droop rheostat of each generator in order to limit the circulating currents. Less droop increases the reactive current that is carried by the generator. Adjusting the voltage droop rheostat in a counterclockwise direction will decrease droop. Adjusting the voltage droop rheostat in a clockwise direction will increase droop. Speed Droop for the Load Division (If Equipped)
Once the two units have been paralleled, the share of the kW load is determined by the governor control setting. If two units of the same capacity and the same governor characteristics have the same governor control settings, the units will share the load equally. The total load must not exceed the capacity of the one engine.In order to transfer the load from one engine, follow the following procedure.
Increase the governor speed control of one unit in order to increase the load.
Reduce the governor speed control of the other unit in order to decrease the load on that unit.
Raise or lower the governor speed control of both units in order to change system frequency. Parallel Operation Of Governors
The different governors that can be used on G3500C generator sets are shown below.
Illustration 2 g00630841
Load Sharing Module (typical example)
The generator set load sharing module provides the droop load sharing for generators that are paralleled. The generator set load sharing module provides the isochronous load sharing for generators that are paralleled. The load sharing