2kw Base Unit Heater

[ekon]

under-plinth/kickplate heater..Winterwarm by Glenn/Dimplex.

Have a double socket on ring main available for this..I was going to connect the heater to the socket with a 13A plug (heater is just over 8A?).

Nothing else will be permanently plugged into the other socket in the double socket.

Just noticed they say must " incorporate a double pole isolating switch having a contact separation of at least 3mm". I am not sure if the socket is SP or DP..they are unused but I bought them ages ago...afraid I have chucked any packaging...& no makers mark on front.

If it is really necessary I'll buy a new DP socket for this job. It's not the cost obviously but the socket, though accessible, is going to be a pig to swap out because its at the back of a unit.

So it's a technical question really..why isn't a SP socket apparently sufficient?

If it IS vital I'll swap it..but if it's not..I'd rather not..plenty else to do right now.

 

[JohnW2]

Just noticed they say must " incorporate a double pole isolating switch having a contact separation of at least 3mm". I am not sure if the socket is SP or DP..they are unused but I bought them ages ago...afraid I have chucked any packaging...& no makers mark on front.

Those instructions presumably relate to the situation in which the heater is 'hard-wired' - are you sure the instructions say that it's OK to use it with a plug & socket (even though, electrically, there is clearly no problem)? Electrically speaking, with a plug and socket, you have the ultimate means of 'double pole isolation' available (3 metres separation if you want ) - simply by pulling the plug out of the socket!

Kind Regards, John

 

[kai]

A Double pole socket for safety perhaps?

The Heater Design Current of Eight amps can easily and safely be handled by a good quality 13amp plug and socket setup, say an MK or Crabtree unit.

 

[JohnW2]

A Double pole socket for safety perhaps?

As I've just written, I think that a call for any sort of 'isolator' is unnecessary if one is connecting via a plug/socket.

Kind Regards, John

 

[ekon]

thanks both..
..>JohnW2..the instructions don't say NOT to use a 13A plug and socket...they just don't refer to it.
I just figured that as I have run a portable 2kw heater quite happily from the same socket, before purchasing this unit, that it would be ok. I like the idea that I could as you say whip the plug out of the socket which is only 1m away.

I have an unused spur junction box not far away that I could use to hardwire the heater with something like this in line:
Crabtree 20amp Double Pole Isolator Switch 4015

but the cable supplied with the heater is only 1.2m long..so I'd have another connection to make before reaching the wall where the isolating switch would be mounted. I don't like that idea much...so that'd mean recabling the heater with longer "flex" which would probably invalidate any warranty!

I note thaton Amazon there's a a 3kW Industrial Tilting Cylinder heater fitted with a 13Amp plug..now that I would be concerned about @12.5 amps!

As kai suggests a decent plug and socket should handle 8A

 

[JohnW2]

thanks both.. >JohnW2..the instructions don't say NOT to use a 13A plug and socket...they just don't refer to it.

Fair enough. I take it, therefore, that the instructions don't say that it 'must' be hard-wired (which would be effectively the same as saying that it 'must not' be used with a plug/socket)?

I just figured that as I have run a portable 2kw heater quite happily from the same socket, before purchasing this unit, that it would be ok. I like the idea that I could as you say whip the plug out of the socket which is only 1m away. ... I have an unused spur junction box not far away that I could use to hardwire the heater with something like this in line: Crabtree 20amp Double Pole Isolator Switch 4015

As I said, as far as I'm concerned, there's nothing electrically wrong with using a plug and socket for an ~8A load - and, if you do, the isolator would become unnecessary.

Kind Regards, John

 

[RF Lighting]

I reckon you'll have more than 3mm contact separation when the heater is unplugged

 

[OwainDIYer]

A single-pole switched socket is not acceptable as someone might assume that if the socket switch is off the appliance is isolated, when it isn't.

An unswitched socket would be acceptable.

If you have any other sockets of the same type that you purchased at the same time, you could check one of those for SP or DP switching.

Or, as I would do, stick a label saying 'remove plug to isolate heater' on it.

Or as I would actually do, just plug it in anyway.

 

[ekon]

fair point Owain..I shall put a label on the heater cable right by the 13A plug reading "'remove plug to isolate heater'".

anyone..is there a way of telling if a socket is SP or DP in the absence of any marking..except by using a continuity tester between N in and N out. (with the power off!) and the switch off..i.e. a visual clue?

Just for the record this is exactly what Glenn/Dimplex wrote in the Instructions: "The cable may be used to connect the heater to the fixed wiring of the premises through a suitable connection box. The supply circuit to the heater must incorporate a double pole isolating switch having a contact separation of at least 3mm."

Guess the crucial bit is "may be used"?

They might also have said "alternately connect the heater to a nearby socket with a 13 Amp plug - preferably connect to a DP socket. If only a SP socket is available ensure that a label which clearly states that to isolate the heater the plug MUST be removed from the socket is affixed to the cable near the plug socket".

 

[EFLImpudence]

They might also have said "alternately connect the heater to a nearby socket with a 13 Amp plug - preferably connect to a DP socket. If only a SP socket is available ensure that a label which clearly states that to isolate the heater the plug MUST be removed from the socket is affixed to the cable near the plug socket".

They can't cater for every scenario.

I'm not being nasty to you but sometimes the instructions say "must be connected by a competent (or qualified) electrician".

That should cover every scenario.

 

[JohnW2]

I reckon you'll have more than 3mm contact separation when the heater is unplugged

Indeed....

Electrically speaking, with a plug and socket, you have the ultimate means of 'double pole isolation' available (3 metres separation if you want ) - simply by pulling the plug out of the socket!

Kind Regards, John

 

[JohnW2]

anyone..is there a way of telling if a socket is SP or DP in the absence of any marking..except by using a continuity tester between N in and N out. (with the power off!) and the switch off..i.e. a visual clue?

No visual clues. There are certainly functional ways in which one could determine whether it was a DP switch but I hesitate to explain them to someone who doesn't already know about them (or other readers).

Kind Regards, John

 

[ekon]

thanks to all..esp. John

 

[westie101]

Given that these units will be sold in countries other than the UK the instructions will no doubt cover all eventualities.
Certainly in some locations polarity is not treated the same as here can can get reversed, this makes double pole isolation more the norm.

Touring caravans generally have double pole switches for the same reasons

 

[JohnW2]

thanks to all..esp. John

You're welcome. Happy New Year!

Kind Regards, John