I came across this animal in none other that Southern California USA, wired into a 30A 240V clothes dryer receptacle with a piece of extension cord... It bears no legible markings & is obviously not domestic from here... Thanks
It looks very mutch like a what used to be termed as a D& S socket(sorry, receptacle) must confess though I never saw one in twin configuration. If it is D&S im going back to the late 1960's. Then it was a very early attempt at a fused outlet. One of the pins in the plug top was fused as I remember. Unless anyone knows different that is.
Aland, sorry to correct you, that's a simple surface-mount double Schuko socket like every hardware store in Austria and Germany sells. Rating 250V 10A DC/16A AC (though no one ever used that for DC). I've had one of those in my room for ages until I renovated and put in a flush mount one. 30A and an extension cord is pretty hefty though.
I take it that the central hole (black spot) is a fastener. What would be the grey spots, positioned centrally towards the middle, of the adaptor? Are these where French ground/earth pins could emerge?
Yes, I've got one here that looks exactly the same. The black things are the rivets that hold the ground scrapers and the grey screws hold the cover. Hutch: It's not an adaptor, it's a real duplex receptacle! I'll post pics of mine as soon as I got my imaging software up again. Mine is mady by Kopp, you can read the brand name on the back side of the bottom part of the receptacle, between the mounting holes. There's also VDE and ÖVE listing and the 10-16/250 rating.
Strange that such a device should turn up in California, but then I once bought a big box full of U.S. wiring devices (mostly Hubbell) at a local junk shop. I reckon it may have been surplus from one of the North Sea oil rigs, some of which apparently are wired to American standards.
Got the box real cheap: Nobody else wanted it......