Cummins/Onan — Planned Maintenance
Maintenance · Transfer switch
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan OTPC
Before you start
- The transfer switch presents a shock hazard that can cause severe personal injury or death unless all AC power is removed.
- Ignition of explosive battery gases can cause severe personal injury. Do not smoke or cause any spark, arc, or flame while servicing batteries.
Procedure
- Disconnect all sources of AC power; turn the genset operation selector switch to Stop; disconnect the battery charger and the starting battery (negative lead first).
- Thoroughly dust and vacuum all controls, meters, switching mechanism components, interior buswork, and connecting lugs.
- Close the cabinet door and wash exterior surfaces with a damp sponge (mild detergent and water); do not allow water to enter the cabinet.
- Check buswork and supporting hardware for carbon tracking, cracks, corrosion, or deterioration.
- Check stationary and movable contacts.
- Check system hardware, control wiring, and power cables for loose connections, wear, or deterioration.
- Tighten buswork, control wiring, power cables, and system hardware as necessary; retorque all cable lug connections.
- Service or replace the 3V lithium batteries in the Digital Module and the Network Module; replace every two years.
- Connect the set starting battery (negative lead last); reconnect normal AC power and verify battery charger operation.
- Test system operation; close and lock the cabinet door.
Specs & values
- Replace batteries every two years
- Lug tightening requirements per Table 3-1
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.