Caterpillar — Low Voltage - Troubleshoot
Testing & diagnosis · Cat Digital Voltage Regulator (CDVR)
From a Caterpillar service manual — check it applies to your exact model before use.
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Before you start
- Electrical shock/electrocution hazard; service by trained personnel only.
Procedure
- Verify voltage adjustment is not set too low; adjust to correct set point.
- Verify under frequency set point (knee frequency) is not greater than generator frequency.
- Verify generator is running at rated speed.
- Determine if system is PMG powered or shunt powered.
- Check for correct input power to the voltage regulator per Electrical specification.
- Verify power potential transformer (if used) has correct turns ratio and correct output voltage.
- Verify sensing potential transformer (if used) has correct turns ratio and is operating correctly.
- Check whether low voltage is caused by droop mode with an inductive load.
- Replace the voltage regulator if prior steps do not correct the problem.
Source: Caterpillar service 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.