Generac — Manually Starting the Unit
Operation · Generator set
From a Generac owner's manual covering: MDG150, MDG175, MDG250. Check it applies to your exact model before use.
Applies to: Generac MDG150, Generac MDG175, Generac MDG250, John Deere 6068HFG05 / 6068HFG06 engine
Before you start
- Equipment damage. Do not attempt to start or operate a unit in need of repair or scheduled maintenance.
Procedure
- Set control power switch to ON (I).
- Display shows pre-start diagnosis; controller loads management software.
- Home screen appears; controller in STOP mode. Press AUTO/MANUAL button for MANUAL mode.
- Press green engine start (I) button to initiate startup.
- If engine fails to start it pauses 15 seconds, then makes two more attempts (three total).
- If it fails to start, fail-to-start alarm shows. Wait two minutes, press ENTER to clear alarm.
- Engine speeds up to a constant 1800 RPM.
- Check for excessive noise, vibration, and coolant, oil, or fuel leaks before loading.
- Verify the AC output voltage is correct.
- Verify frequency reads approximately 60 Hz with no loads connected.
- Switch main circuit breaker to ON (I), then add loads via their circuit breakers.
Specs & values
- Operating speed 1800 RPM
- Frequency approximately 60 Hz
Full service-parts list: Generac MDG150 →, Generac MDG175 →, Generac MDG250 →, John Deere 6068HFG05 / 6068HFG06 engine →
Source: Generac 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.