Cummins/Onan — AC Load Connections (Circuit Breaker)
Installation · Circuit breaker box
From a Cummins/Onan service manual covering: C25 D6, C30 D6, C35 D6, C40 D6, C50 D6, C60 D6. Check it applies to your exact model before use.
Applies to: Cummins/Onan C25 D6, Cummins/Onan C30 D6, Cummins/Onan C35 D6, Cummins/Onan C40 D6, Cummins/Onan C50 D6, Cummins/Onan C60 D6, Cummins/Onan 4BT3.3 engine
Before you start
- Improper installation can lead to electrocution and property damage.
Procedure
- Shut down and disable the generator set (Off then E-Stop, cool down).
- Turn off battery charger AC and disconnect negative battery cable.
- Remove enclosure side panel to access main circuit breaker box.
- Place circuit breaker handle in OFF position.
- Remove four bolts holding circuit breaker cover.
- Connect conductors to load-side terminals, neutral lug, and grounding lug.
- Torque circuit breaker terminals per breaker label.
- Torque neutral lug to 31.1 Nm (275 in-lb).
- Torque equipment grounding lug to 13.8 Nm (120 in-lb).
- Fill stub-up openings with duct seal or mastic tape.
- Install circuit breaker cover.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Neutral lug 31.1 Nm (275 in-lb)
- Ground lug 13.8 Nm (120 in-lb)
Full service-parts list: Cummins/Onan C25 D6 →, Cummins/Onan C35 D6 →, Cummins/Onan C50 D6 →, Cummins/Onan C60 D6 →
Source: Cummins/Onan 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.