Generator Mods

By Rob Farrow

The GenSet on Catherine Ann is the original Onan 6.5 KW with a couple of interesting modifications. It has been completely rebuilt using all original parts (every part still available through Onan/Cummins but ridiculously expensive) I did change the ignition system from the original fully shielded coil, wires and plugs, (which would have been over a thousand dollars to replace) to a system using conventional wires and plugs, plus a GM truck coil. Since the main engines on each side of this generator use conventional ignition systems, having a fully shielded system on the generator did not make sense. (There has been no change in electrical interference with any other systems)




As originally designed, this GenSet uses a 13 HP engine to produce about 50 amps at 120V and about 15 amps at 13.5V to charge the battery. What I really needed was about 80 amps at 13.5V to quickly recharge the house batteries, but I would seldom need more than about 30 amps at 120V. The solution was to mount a marine alternator to the GenSet. This unit takes about 1/3 of the available HP at full load, reducing the 120V amperage available, but quickly charges the 12V house bank at 80 amps, whenever the Genset runs.

If you are thinking about something like this, please contact me for more specific details.

Rob Farrow

Catherine Ann

January 2009