Marathon — Starting Up the Generator (First Time)
Operation
From a Marathon service manual — check it applies to your exact model before use.
Before you start
- Do not overspeed the generator; excessive centrifugal forces could damage the rotating fields.
Procedure
- Disconnect generator output from load; be certain main circuit breaker is open.
- Disable the voltage regulator by removing the fuse.
- Follow manufacturer instructions and start the prime mover; adjust rpm to nameplate.
- Replace regulator fuse and adjust voltage to required value.
- Check all line-to-line and line-to-L0 voltages correct and balanced.
- Close main circuit breaker and apply the load.
- Monitor generator output current; verify at or below nameplate amps.
- Adjust engine speed at full load to 1800 rpm (60 Hz) or 1500 rpm (50 Hz); before stopping remove load by tripping breaker.
Tools required
- Voltmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 1800 rpm for 60 Hz
- 1500 rpm for 50 Hz
Source: Marathon 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.