Contactor for oven

[Bradley6969]

Hi, working on a job, guy wants all appliances on grid switch, the oven needs 32amp supply so best way I can think of is 6mm into contactor 6mm to cooker then 1.0mm from contactor to 20amp DP in grid switch to keep it on grid???
Thing confusing me is the grid is on a 4mm 32amp at the moment and the 6mm will be from a 32amp MCB but that will mean the DP controlling contactor is on one circuit and oven fed between contactor is on another
Thanks

 

[Andy78]

Search for click minigrid. They do a 32A DP grid switch.

 

[buzzlightyear]

6mm to cooker then 1.0mm from contactor to 20amp DP in grid switch to keep it on grid

?????? three words

 

[goasis]

"6mm will be from a 32amp MCB but that will mean the DP controlling contactor is on one circuit and oven fed between contactor is on another"

Maybe I'm misunderstanding but isn't that the whole point?

 

[davesparks]

Hi, working on a job, guy wants all appliances on grid switch, the oven needs 32amp supply so best way I can think of is 6mm into contactor 6mm to cooker then 1.0mm from contactor to 20amp DP in grid switch to keep it on grid???
Thing confusing me is the grid is on a 4mm 32amp at the moment and the 6mm will be from a 32amp MCB but that will mean the DP controlling contactor is on one circuit and oven fed between contactor is on another
Thanks

That's one of the reasons contactors exist, to be able to use one circuit to control a different circuit without them being linked.

The switch operating the contactor obviously won't be directly connected to the 4mm 32A circuit anyway, you'll have a smaller ocpd protecting the 1.0mm and the contactor won't you?

 

[Bradley6969]

That's one of the reasons contactors exist, to be able to use one circuit to control a different circuit without them being linked.

The switch operating the contactor obviously won't be directly connected to the 4mm 32A circuit anyway, you'll have a smaller ocpd protecting the 1.0mm and the contactor won't you?

The 6mm will be on a 32a MCB so my supply circuit for oven, and the 1.0mm controlling the switching on the contactor was going to come from the 20amp DP in grid switch which is on a 4mm 32amp radial?
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"6mm will be from a 32amp MCB but that will mean the DP controlling contactor is on one circuit and oven fed between contactor is on another"

Maybe I'm misunderstanding but isn't that the whole point?

Yes sorry it’s more to do with the 6mm into contactor and out to oven is on 6mm 32amp MCB then the 20amp DP controlling the contactor is on a 1.0mm but will be on the 4mm 32amp radial for grid switches?

 

[suffolkspark]

Sounds a pointlessly messy setup just use the click grid as Andy sujested

 

[Bradley6969]

Sounds a pointlessly messy setup just use the click grid as Andy sujested

All bought now can’t get one for today

 

[davesparks]

The 6mm will be on a 32a MCB so my supply circuit for oven, and the 1.0mm controlling the switching on the contactor was going to come from the 20amp DP in grid switch which is on a 4mm 32amp radial?

There must be another fuse there somewhere, you can't just connect 1.0mm and a contactor directly to a 32A circuit!

Also how often is the customer intending to switch the cooker on and off? I assume you've confirmed they only turn it on to cook and won't be leaving it on 24hours a day? If not then how long do you think that contactor is going to last?

 

[Bradley6969]

There must be another fuse there somewhere, you can't just connect 1.0mm and a contactor directly to a 32A circuit!

Also how often is the customer intending to switch the cooker on and off? I assume you've confirmed they only turn it on to cook and won't be leaving it on 24hours a day? If not then how long do you think that contactor is going to last?

The 1.0mm is only Switching the contactor?
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The 1.0mm is only Switching the contactor?

Through a 20amp DP I’ll use 2.5mm it’s only switch through the DP

 

[davesparks]

The 1.0mm is only Switching the contactor?

Yes, but 1.0mm can't be protected by a 32A MCB and your posts so far suggest that this is what will happen.
Also protecting the contactor coil with a 32A MCB is not a good plan either.

Why not fit a 1A fuse or MCB in the enclosure next to the contactor, feed it from the cooker supply and use the 1.0mm from the grid switch as L and S/L?

 

[DPG]

The 1.0mm is only Switching the contactor?
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Through a 20amp DP I’ll use 2.5mm it’s only switch through the DP

20A switch yes, but isn't it fed from a 32A RFC?

 

[Bradley6969]

20A switch yes, but isn't it fed from a 32A RFC?

All the grid is on a 4mm radial 32amp in and out each fused appliance the contactor will be switched of the 20amp DP which is on the 4mm radial? With 2.5mm??
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Yes, but 1.0mm can't be protected by a 32A MCB and your posts so far suggest that this is what will happen.
Also protecting the contactor coil with a 32A MCB is not a good plan either.

Why not fit a 1A fuse or MCB in the enclosure next to the contactor, feed it from the cooker supply and use the 1.0mm from the grid switch as L and S/L?

Oh I see so I can’t protect the coil with the 20amp DP fed from 32amp radial?

 

[DPG]

But you said the 1mm contactor coil feed was going to be taken from the RFC. The RFC is protected by a 32A device is it not?

 

[suffolkspark]

Literally this is such a muddle... why not just order the 32A dp switch which is perfect for the job, electrical2go sell them, and then go back and swap, I'd put it on the 20A dp you have for now and put a 20a mcb in?

 

[Bradley6969]

But you said the 1mm contactor coil feed was going to be taken from the RFC. The RFC is protected by a 32A device is it not?

Yes I see now, so if I put the 20amp DP on a 20amp MCB send a 2.5mm 3 core from contactor to 20amp DP so will have Perm L from MCB and SL to contactor cool and N which isn’t needed which will just go straight to contactor
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Literally this is such a muddle... why not just order the 32A dp switch which is perfect for the job, electrical2go sell them, and then go back and swap, I'd put it on the 20A dp you have for now and put a 20a mcb in?

It’s bought now, plus I’m working with a sparky anyway I’m not qualified but doesn’t seem to know hence why I’ve asked on here

 

[Spoon]

It’s bought now, plus I’m working with a sparky anyway I’m not qualified but doesn’t seem to know hence why I’ve asked on here

Why are you not asking the sparky who you are working with?

 

[Bradley6969]

Why are you not asking the sparky who you are working with?

He’s a subby so ain’t intersted in showing me

 

[westward10]

As previously stated the control circuit (coil) requires circuit protection. Fit a spur next to the contactor enclosure or a fuse within. Connect the fuse from the incoming supply at the contactor (neutral direct to the coil) then a two core to the grid switch to switch the line for the coil.

 

[DPG]

How come you have been paired with someone who is not interested in helping you learn things while you get qualified?