"All Pole Disconnection Device with a 3mm contact gap&q

[peterkonczak]

Hello all,

I need to install a 3KW space/wall heater and the instructions state that connection to the mains power should be "by the way of a suitably rated all pole disconnection device with a minimum of 3mm connection gap and protected by an appropriately rated circuit breaker."

The unit has a pre-wired 1 meter mains cable from the back.

Could someone please explain to me the best way to connect this device?
There's wall socket not too far away, can that be used at all?

Thanks,
Pete

 

[Chri5]

Use a 13 amp fused spur, MK are 3mm gap and 2 pole (Live and Neutral).

If it's in a bathroom and the circuit isn't RCD protected at the CU / Fuse board then use a RCD fused spur (but check with supplier re:3mm gap).

Both will replace a standard single socket plate, so they are a direct swap.


Could you confirm what the existing socket that you mention does ? It needs to be part of a ring circuit of other sockets, or even a radial. But you do need to check it over- if it is part of the lighting circuit then DO NOT use it, it will overload the circuit and will be under correct wire size for the heater load.

 

[mikhailfaradayski]

There is a suggestion that permanently fixed heating appliances over 2kW should be fed from its own dedicated circuit.

 

[holmslaw]

..

 

[peterkonczak]

Thanks for the help guys...

Apologies, the socket I mentioned is a double-socket and part of a radial circuit of other sockets. It is not going in a bathroom.

Cheers,
Pete

 

[Chri5]

Use a 13 amp fused spur, MK are 3mm gap and 2 pole (Live and Neutral).

If it's in a bathroom and the circuit isn't RCD protected at the CU / Fuse board then use a RCD fused spur (but check with supplier re:3mm gap).

Chri5 are you sure MK have a 3mm gap?

I just checked BS1363 and it only calls for a 1.2mm gap.

3p fan iso, switches and socket are ! But I can't find anything that states a f/spur is !


Now I have a better picture from the op, then I'd suggest a 13a plug on the lead and use the socket.

 

[tonyelectric]

MEM exel 15A 3 pole switchfuse for that industrial look

If its 3KW it should be OK on a spur but agreed better on a dedicated circuit, 3mm is quite a big clearance, is the appliance made somewhere less electrically sophisticated than we are (like 110V land)??

 

[peterkonczak]

It's a Bush Nelson Thermic 730 Heater:

http://www.bnthermic.co.uk/product.php?id=2

 

[tonyelectric]

Good choice, and made in blighty, well theres many of these running happily on crabtree spurs at our local railway station so i'll stick with the suggestion of a standard spur.

 

[Monkeh]

MEM exel 15A 3 pole switchfuse for that industrial look

If its 3KW it should be OK on a spur but agreed better on a dedicated circuit, 3mm is quite a big clearance, is the appliance made somewhere less electrically sophisticated than we are (like 110V land)??

Why would they require a greater clearance when operating at a lower voltage? Logic, man.

 

[ColJack]

erm... ohms law?????

or one of it's cousins.. the power one..

if it's 3KW then at 230V it's a little over 13A
at 110V it would be a little over 27A...
higher amperage means a bigger gap so you don't get arcing..

 

[tonyelectric]

Larger current, most US switchgear is beefier than ours as appliances draw more current to run than if they were working on 230V

 

[Monkeh]

erm... ohms law?????

or one of it's cousins.. the power one..

if it's 3KW then at 230V it's a little over 13A
at 110V it would be a little over 27A...
higher amperage mens a bigger gap so you don't get arcing..

Point, I don't usually think of yanks having 3KW equipment, usually 2KW tops, which isn't so bad.

 

[tonyelectric]

Col Jack you pipped me to the post

If you ever get stateside monkeh check out some of the scary electrical practices they use and the wobbly plugs.

When you see the electric chair in films and the lights all flicker you've got to wonder why it's not fed off a dedicated supply - mine in the cellar for non paying customers is

 

[Monkeh]

Oh, I know a couple of yank sparkies, I know all about their electrical ideas.