just found contactors on a domestic cooker circuit.

[Therolster]

Hi all. New to this site. Just been to check out the electrics for a friend that has moved house. Consumer unit is part RCD / part not i.e 16th. BUT he has a totally odd wiring set up for the cooker circuits. Consumer unit has a breaker 32amp for hob and another breaker 32amp, for the cooker BUT the wiring comes from these breakers to a box below the consumer unit that contains two contactors. Merling Gerin Multi 9 CT 40 Amp AC1 415V then into the cooker. The cooker breaker is acting as the switch circuit as well, to engage the contactors. It's a standard electric oven and hob. single phase. This contactor unit looks older than the consumer unit. Could it have been there originally running something more powerful and whoever put the new CU in just used it??
Over to the more experienced chaps amongst this forum AND any answer would be gratefully received.

Many thanks in advance.

Therolster

 

[Hawk81]

the contactors were maybe installed to save having to fit 2 32amp isolators. maybe there is grid switches or something like that to switch them.

 

[Therolster]

Cheers Hawk and thanks for the quick response. It was a flying visit but I'm back next saturday and will check it out more. From what I can see though = no grid switches at all. It's an old bungalow.
Why the need for isolators? They have a separate breaker for the oven and one for the hob and I have to say, the hob and oven are nothing special. You can isolate them by flicking the breaker?
The wiring in the place does not provide for above work surface isolation like we see now. Just dont get it. The contactors are three phase types but only being used to switch single phase cooker. You could pull it out and put a bar in and connect the in and out. No reason to have these contactors as far as I can see. Single phase in to the house. Not even a dual supply/timer i.e. they have gas for the heating. all the very best. The rolster

 

[EddieB]

Chances are the house was owned by an engineer at some time, for some reason these guys are so use to industrial factory work and development that they seem to think that domestics should be the same I've been involved in a couple of houses where belt,braces and the whole nine yards have been applied

 

[Steve1412]

Could understand if the coils had been switched thru heat detector or something else along the safety lines for OAP???????
As it stands then if the oven O/Ls the oven and hob will be isolated.....if the hob only O/Ls..just the hob is isolated??????
Everyday its a challenge...lol