Sealey EH3300 drawing 30 Amps!

[ringer]

Customer has bought a Sealey EH3300 heater. He tried putting it on a plugtop and it didn't work, so he has asked me to connect it. It is, as the name suggests, a 3.3kW heater. No problem, thought I, it can be installed on a fused spur to an existing radial circuit containing just three little-used double sockets. Radial is 2.5mm^2 T&E. When I went to check manufacturer's info to determine fuse size required - they say it draws 30 Amps! So where does that 30 Amps come from? The heater is rated at 3.3kW - is it so inefficient, it consumes 6.9kW and only outputs 3.3kW? I would contact Sealey myself to ask, but seeing as how there's some sort of holiday going on, I doubt I will get a reply for a few days at least. Can anyone shed any light on this?

Instruction leaflet

 

[Sparky Ninja]

Well 3.3kW would clearly never have been suitable with a 13A fuse in the first place. As to why it suggests 30A I cannot see anything specific within the instructions..

It could be to with with in-rush or tolerance being too close to a 16amp so manufacturers consider the 30 Amp fuse and plug top to be more reliable?!?!?

In these cases, the regulations will just state to follow manufacturers instructions.

 

[Darkwood]

The online instructions suggest using a industrial round pin style plug and with this model shouldnt be put on a 13amp plug top, i assume due to its rating been constant and it could be running for a long duration it makes the suggestion of 30amp supply so as to recommend a blue 2pin and earth plug and socket assembly as a 16amp may get hot if used for many hours, this is common too with 3kw heaters on 13amp plug tops running for hours that the plug or socket will burn out even though they are within the rating. I assume you can wire a 20amp supply but use 30amp connection equipment to reduce the chances of overheating.

 

[Marvo]

I would go with a 20 amp MCB on a 20amp circuit with a 32 amp plug and socket. I prefer an isolator to be an integral part of the socket and mechanically interlocked with the plug. This prevents the heater being unplugged whilst power is on, that way the plug and socket don't get arc damage and last longer.

 

[telectrix]

usefull comment there, Marvo.

 

[ringer]

... I prefer an isolator to be an integral part of the socket and mechanically interlocked with the plug....

Agreed, good point there Marvo, except this is single phase and I have only seen integral isolators on 3-phase sockets. Do you know where I can get a 230V 32A socket with integral isolator from?

 

[Marvo]

There are single phase available, they're often called '2 phase + eth' and the isolator is 2-pole. We've used the Gewiss range in the past and they've always been solid. The link is for a South African distributor but I'm sure they're available at a wholesaler local to you. You could also check out the Marechal range of sockets as well, also good equipment......although I think they may be French......I'm trying to think of something manufactured in the UK but failing miserably I'm afraid.

 

[UNG]

How about this company in the UK

CEE Norm U.K. Limited

Do a full range of industrial plugs and sockets

 

[Knobhead]

This may sound silly but check the rating plate 3.3KW = 30A @ 110V

 

[ukpablo]

good point tony?!

 

[ringer]

Sealey's spec sheet definitely says 230V and 30A. Am going to call their technical helpline (when I can find the time).

 

[malcolmsanford]

You may find that if it's exported it may have dual capacity ie wired for 220/16amp 110/30amp see a lot of equipment over here like this that gives the 2 options.