Surge protector

[chessie4905]

Anyone familiar with these?

[windtrader]

looks like a real old plug adapter, long before they made the molded ones.

[chessie4905]

No, plug and socket 50 amp. Electronics inside.

[TNBrett]

post a pic of the inside.  It's probably something like a voltage sensing relay.  It senses the voltage coming in and only closes the contacts if the voltage is say between 215-250v.  That would be fairly easy to do inside an enclosure like that with off the shelf parts. 

[chessie4905]

Pictures of inside.

[dtcerrato]

Pictures of inside.

I see a heavy contactor and a printed circuit board. The circuit board probably keeps the contactor in the normally closed position when things are normal and rapidly opens the contactor when voltage outside of it's set perimeters are present. That's my guess.

[windtrader]

I agree with Dan. There are contacts so I will assume one end of the wire to the box goes to one side and the other wire goes to the other side of the contactor. I can't determine if it is NO or NC but that board does detect some electrical level or condition and either opens or closes the contact.

It could montior low voltage and prevents power from passing until it is in range. It could monitor high voltage and cutoff power if too much comes in, spikes too? If there is capacitors then that could indicate some form of surge protection.
In any event, it is generations old and something like that is dime a dozen, once you figure out what it does. lol

[luvrbus]

The generator to shore power change overs with surge protectors look about the same inside as that

[chessie4905]

Did some research. Company sold surge protectors a while back. No longer in business. Thought one of the geezers here may have had one.