Cummins/Onan — Connecting the Load
Installation · Generator terminal block
From a Cummins/Onan service manual covering: 275 DFBF, 300 DFCB, 350 DFCC. Check it applies to your exact model before use.
Applies to: Cummins/Onan 275 DFBF, Cummins/Onan 300 DFCB, Cummins/Onan 350 DFCC, Cummins/Onan NT-855-G6 engine, Cummins/Onan NTA-855-G2 engine, Cummins/Onan NTA855-G3 engine
Before you start
- Do not connect generator set directly to any building electrical system; connect only through an approved isolation switch or paralleling device.
Procedure
- Bolt load wires to the appropriate terminals on the generator terminal block.
- Terminals are stamped U, V, W and N (U, V, W = L1, L2, L3; N = L0).
- Route generator output leads through current transformers CT21, CT22 and CT23 for meter operation.
- Balance loads so current from each line terminal is about the same.
- Ensure each line current is within 10 percent of median value and below nameplate rating.
Specs & values
- Line current within 10 percent of median value
Full service-parts list: Cummins/Onan 275 DFBF →, Cummins/Onan 350 DFCC →
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.