Cummins/Onan — Replacing Circuit Breakers
Repair & overhaul · AC output / transformer circuit breakers
From a Cummins/Onan owner's manual covering: 1.5HJBAA, 2.0HJBAA, 2.5HJBAA, 3.0HJBAA. Check it applies to your exact model before use.
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Procedure
- Turn OFF the AC circuit breaker supplying power to the Inverter-Charger.
- Disconnect the batteries from the Inverter-Charger.
- Remove the AC terminal block cover and disconnect all wires from the AC terminal block.
- Remove all plug-in connectors to external circuits.
- Remove the Inverter-Charger.
- Use a torx T20 bit to remove the 12 screws that attach the cover to the base.
- Remove the cover by sliding it straight back 3/4 inch and then lifting it straight up.
- Disconnect the two wires (quick-connects) from the circuit breaker to be removed; note the terminals.
- Remove the two Phillips mounting screws, mount the new circuit breaker (same rating, 15 or 20 amps) and reconnect the wires.
- Complete the installation in reverse order of removal and test for proper operation.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Replacement circuit breaker must have the same rating as the old one (15 amps or 20 amps)
Source: Cummins/Onan 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.