My customer has an older Coleman 5Kw Powermate PM0525202.

Problem is that the receptacle is different - it's got a 6-20R rather than an L14-20R (one flat and one 90deg rotated blade vs. 4 prong twistlock). I checked the Coleman site - no schematic. I assume the neutral and the GND are bonded inside the unit. There is a separate 120 v duplex on the unit.

Has anyone ever changed out the receptacle so the neutral and GND are brought out separately. I plan to back-feed the panel with a Square D interlock.

Thanks for help!

Coleman says it should have a twistlock. Are you sure that is the right model number?

If you are talking about the 3 wire 240v receptacle on that generator, check carefully, as I'm pretty sure there is no midpoint neutral just straight 240v.

Yup, sure of the model # - it's an older model; current models have the 4 conductor twist lock.

My custoer's unit has what appears to be 2 duplex receptacles, one marked 120V and the other marked 240V - a 5-20R and a 6-20R. Tells me there's got to be a neutral somewhere......

You could meter it out. If the neutral is bonded you should see 0 ohms between the neutral and ground on the NEMA 5-15s and the ground on the 6-20. To be connected properly your transfer equipment should also be switching the neutral.