Caterpillar — Generator - Dry (Controlled Current Method)
Maintenance
From a Caterpillar owner's manual covering: 3306B, 3406, 3406E, 3412C, 3412C Generator Set, 3500 Series. Check it applies to your exact model before use.
Applies to: Caterpillar 3306B, Caterpillar 3406, Caterpillar 3406E, Caterpillar 3412C, Caterpillar 3412C engine
Before you start
- Personal injury or death can result from improper troubleshooting and repair procedures.
Procedure
- Make an external power source.
- Disconnect F1+ and F2- from voltage regulator; disconnect generator load.
- Connect rheostat at maximum resistance and external power source to F1+ and F2-.
- Start generator set and run at IDLE speed.
- Monitor phase current; gradually increase RPM until rated phase current or full speed.
- Slowly turn rheostat until rated phase current is reached.
- On an hourly basis stop and check insulation resistance.
- Repeat until insulation resistance is acceptable.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Raise winding temperature gradually at 10 C (50 F) per hour up to 85 C (185 F)
Full service-parts list: Caterpillar 3406 →, Caterpillar 3406E →, Caterpillar 3412C →, Caterpillar 3412C engine →
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.