I have no idea what it is myself but, the site in the link below seems to have a lot of interesting info on older gensets. Maybe you could try posting that pic there and someone could possibly identify it for you.

Gensets

Thanks for that - have posted a message there to see if anybody can identify.

Is this connector wired to the Output of the generator?

What is the generator output? (Volts & Hertz)

It reminds me of the old trailer running lamps connectors.

Larry C

Hi Larry, thanks for your interest.
Yes, the outlet is wired to the output of the generator.
The generator runs at 50hz, not sure of the voltage yet as the engine needs attention, so I've only managed to get 72 volts out of it so far.
There is a circle on the outlet which reads 25/300, which I assume to be 25 amps/300 volts.
There is a plate on the generator, which, roughly translated suggests that the 115v outlet should be used for light/heat only, not for motors - but I think that is the round 2 pin socket.

Do you think the output is 3 phase?

Is the single contact in the brown part of the connector, connected to the frame?

Larry

What country/language? That could be a clue.

Yes I think it's 3 phase, and the wire connected to the bottom part is the earth wire. Don't know where it goes to because I haven't taken it apart that far yet.

The instructions are all in German.

Thanks for your interest.

I asked a friend from Germany who deals a lot with old equipment. He said it's a 380V 3ph connector, only used on military equipment (both Western and Eastern Germany, he suspects this one is Eastern based on the paint color). Apparently it's 380V 25A 3ph+ earth.

Thanks Texas Ranger, and thank you friend too. That's really great information. I don't suppose your friend would have any idea how old it might be?

His best guess is 1950s but he said it would be easier to tell with more detailed pictures (especially with the cover off).