Caterpillar — Parallel Operation - Voltage Adjustment
Adjustments · Voltage Regulator
From a Caterpillar owner's manual covering: 7C-1000, 9Y-1300, 9Y-1400, SR4. Check it applies to your exact model before use.
Applies to: Caterpillar SR4
Before you start
- Damage to the generator is possible. Do NOT exceed rated ampere load on any single generator.
Procedure
- Adjust voltage as described for Single Unit Operation, Initial Start-Up.
- With the engine running at rated speed, turn the voltage droop clockwise about 1/2 of full range.
- Readjust the voltage level control until the voltage is about 5% above desired voltage.
- Apply full load.
- Readjust the voltage droop control to obtain desired voltage with full load at 0.8 power factor.
- Repeat Steps 3, 4 and 5 for each generator to be paralleled until line voltage is equal to desired level at full load and no load voltage is approximately 5% above rated voltage.
- Parallel generators and apply the driven load; adjust voltage droop controls to share current proportionally.
- Make final adjustments after paralleled generators have been running at full load for one hour or more; tighten locknuts and install the access cover.
Tools required
- Voltmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Loads of 0.8 power factor require a generator voltage droop of about 5%
- Voltage droop clockwise about 1/2 of full range
Source: Caterpillar owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.