Black box in old consumer unit - electrician stumped.

[alexkx3]

Can any of you old pros out there help identify the middle black box made by Engel and Gibbs ltd. It buzzes sporadically, even when the main supply to the flat is off.

My electrician has never seen it before and can't figure out.

Thanks,

Alex

 

[telectrix]

my guess would be a contactor, possibly for the floor heating circuit/s.

 

[KEV 1 N]

Possibly a contactor, possibly to do with the economy7 system as it appears there is electric heating

 

[telectrix]

might that be energised by the radio teleswitch?

 

[Pete999]

I reckon it's a Transistorised relay (Engel and Gibbs) could be used to switch ON and Off the floor warming system.

 

[Lucien Nunes]

Agreed - probably underfloor heating contactor or mercury relay. Unusual design, would be interested to see inside (the cover comes off with two knurled nuts). If it turns out to be something interesting, I'd pay to have it posted here for the museum!

 

[Chris1234]

Did he not open it?

 

[telectrix]

Did he not open it?

are you mad? there could be spiders inside.

 

[Chris1234]

I’d have opened it at the first opportunity to see what it was!

 

[Des 56]

If there's one of these inside,best run a way fast

 

[alexkx3]

Thanks for the information guys. I've uploaded a photo under the hood.

 

[Richard Burns]

It certainly looks like a contactor and with nicely toasted terminals as well.

 

[alexkx3]

Good to know, what does a contractor do exactly and is it meant to buzz? Haha

 

[pirate]

No, it's a doorbell transformer that buzzes...

 

[Last plumber]

Thanks for the information guys. I've uploaded a photo under the hood.

View attachment 41500

I think it is a solenoid driven mercury tilt switch.
Be careful if it is, as you know Mercury is poisonous.
If you are going to dispose of them, they have to be treated as hazardous/poisonous waste.
Used for the same purpose to a contact set.
A control circuit operated the solenoid which in turn tilted the switch and the Mercury would make contact between two terminals in order to to carry a heavier load, e.g. Electric Underfloor Heating
The buzzing will likely be the solenoids.