Onan RS4500... NICE GENSET! Great price on it too. And good news, you can use any ATS that supports two-wire start, so the GE ZTX40MX60 400A ATS will work no problem. The #3 terminal gets grounded (on the DC side) to terminal #1. These two terminals connect to the two start terminals on the ATS.
The only real difference between the GE and Onan version is the Onan switch has slightly different firmware (the genset transfers over with a shorter delay) and includes a built-in battery charger. It should be noted, however, that the GE version of the switch has the studs already in place on the lower LH portion of the enclosure to accept the charger, and push on terminals above the lugs to power it. Seems kind of cheezy to to have thin little wires connected right above the big current carrying cables, but that's the way the Onan version comes from the factory.
If you need OEM type the battery charger specs, let me know.
Looks like you just saved your customer lots of money.
Joe
