very hot 13 amp plugs

[mattysupra]

Hi, we are running some 3kw heaters.

All are brand new and plugged into plugs that are all on separate ring mains.
(new rewire and i know what sections of the building are on what ring)


Every one of the plugs are getting very hot. The outside of the plugs are getting very warm but when i unplugged one and touched the actual metal prong in burnt me. Also the flex to the heaters is very warm, however i touched some of the 2.5mm cable feeding the plug sockets and this felt cold apart from when i got close to the socket (within 50cm )

Are these heaters fit for purpose? im scared to leave them turned on while im not around.

Should i be worried?

 

[Jackrae]

I'd suggest YES

Many of the 13A plugs and sockets available on the UK market that are supposed to be fit for purpose are really cheaply manufactured and a serious cause for concern when loaded to their specified full load rating. Personally I only use the one manufacturer of 13A plugs. They use the letters M and K in their name.

As to the heater cable getting very warm, it is clearly not fit for purpose so I suggest you contact your local trading standards to examine the product on the grounds of consumer safety. I presume the plug fitted is moulded to the cable.

What is the manufacturer of both the sockets and the plugs

 

[EFLImpudence]

Did the heaters come with plugs fitted.

3kW is technically alright for plugging in but fuses and plugs do not seem to like it.
Some sockets and plugs do not seem to be made very well.

If the contacts are a bit slack they will get hot.
As the cable is also hot, this too would seem to be too small.


If the heaters did come with plug I would contact the manufacturer.
If not, then hard-wiring using a larger cable should remove the problem.

 

[mattysupra]

The plugs on the heaters are molded type.

The flex seems pretty heavy duty. defo bigger than 1.5mm.

The actually sockets are brand new but i dont know who makes them.

The heaters are also brand new but of two different brands. They are honeywell and clarke heaters.


I dont want them hard wired as i move them to which ever area of the building we are using. (large building which we are waiting for gas heating to be installed)

 

[mattysupra]

would be worth me swapping one of the sockets with a mk socket to see if this eliminates the problem?

im guessing the flex is getting warm due to heat traveling down the flex from the socket?

 

[EFLImpudence]

You could try. Let us know the outcome, please.

 

[JohnD]

When you remove the old sockets, observe how well-fitted the wires are, and how tight the connectors.

Should be "very'

Are they double sockets? Are two appliances in use at the same time? What are they?

 

[viewer]

Can you take a heater to a friend's house and see if it has the same problems?

 

[joe-90]

If a fuse is close to blowing, wouldn't it act like a tiny heater within the plug itself? Could that be where the heat is generated?

 

[Jackrae]

Indeed, a 13A fuse will get warm when it's carrying its rated current (it is a resistive device) but is designed to carry 13A, not blow at 13A.
That's why the design of the plug is critical. Some of the cheap plugs have fuse carriers that look a bit like earwig pincers and only clamp the fuse by point contact, which itself adds heat to the system. The better plugs, such as MK, employ a fuse carrier which holds the whole fuse cap and therefore is capable of carrying a warm fuse without point contact heating.

If you are considering changing a socket, it is essential that you also consider changing the plug top as well, since a faulty plug top will not eliminate the problem. In fact the easier option for experimentation is to change the plug first since you are not them mucking about with your ring main.

 

[joe-90]

Some of the cheap plugs have fuse carriers
that look a bit like earwig pincers

They sure do.

 

[bernardgreen]

If the fitted cable is getting warm then I would be suspicious of the quality of the heaters. Having a well known brand name on the product is no longer a garantee of good ( or even adequate ) quality.

It is not impossible that the cable is marked as one size but has less copper than it should have for that size.

I never trust a moulded on plug if the load is more than a couple of amps and replace them with a new one. It also allows a check on the actual cross section of the cable.

Some very poor, even criminally poor, cost cutting assembly and design can be hidden inside a moulded on plug.

The regulation about having to have fitted plugs did not take account of the poor quality counterfiet market taking advantage.

 

[Johnmelad]

If the fitted cable is getting warm then I would be suspicious of the quality of the heaters. Having a well known brand name on the product is no longer a garantee of good ( or even adequate ) quality.

It is not impossible that the cable is marked as one size but has less copper than it should have for that size.

I never trust a moulded on plug if the load is more than a couple of amps and replace them with a new one. It also allows a check on the actual cross section of the cable.

Some very poor, even criminally poor, cost cutting assembly and design can be hidden inside a moulded on plug.

The regulation about having to have fitted plugs did not take account of the poor quality counterfiet market taking advantage.

There is scarcely anything in the world that some man cannot make a little worse, and sell a little more cheaply. The person who buys on price alone is this man's lawful prey.
John Ruskin (1819-1900)

 

[ban-all-sheds]

If you are considering changing a socket, it is essential that you also consider changing the plug top as well

I think it would be better to change the entire plug.

 

[bernardgreen]

Some of the counterfeit / poor quality items are not cheap to buy, just a few percent cheaper than the genuine items.