Burnt Out 13-Amp Plug

[Oatsie]

Hi

Running a 3KW fan heater on an extension lead. Thought there was an issue with the double socket. Tried right hand side socket, then left.

Then realised after seeing burn marks on the left socket, that it was the plug overheating. 13 amp fuse fine and RCD on consumer unit not tripped.

This in a garden office which gets cold, but not damp.

Is this a plug issue or fan heater issue? Surely if a fan heater issue it would blow the fuse or RCD. Suspect it's a non-kosher plug not being able to take 3KW, but MP are an OK brand aren't they?

 

[EFLImpudence]

Loose/poor connection somewhere. Looks like the fuse holder or pin rivet.

Nothing to do with the heater itself.

 

[JohnD]

it's curious that the colour marking on the fuse looks to be violet. It should be brown.

the picture suggests that the fuse itself overheated, mostly at the bottom. This is unusual. The metal gripper should be a tight fit.

Do you recall where the plug came from? There are some poor-quality foreign imports around.

The socket will also need to be replaced with new.

 

[Oatsie]

The connections are tight and solid. The colour of the burn is definitely brown; must be the phone camera. It is a MasterPlug single socket 5m extension from HomeBase. It doesn't have a CE or BS mark on the plug. The single socket says BS1363/A.

 

[JohnW2]

the picture suggests that the fuse itself overheated, mostly at the bottom. This is unusual. The metal gripper should be a tight fit.

The fuse itself shows no sign of overheating, the problem all being at it's (lower end) connection to the plug's L pin. As EFLI said, presumably the 'gripper' is not 'a tight fit' and/or the rivet attaching it to the plug's pin is 'loose'.

Kind Regards, John

 

[winston1]

Surely if a fan heater issue it would blow the fuse or RCD

Fuses blow on overload. 3kW is not an overload on a 13 amp fuse.

RCDs trip (not blow) on unbalance such as earth leakage, not overload.

There are some schools of thought that say the UK 13amp plug does not handle 13 amps. I believe the Post Office down rated them to 8amps on their properties.

 

[JohnW2]

There are some schools of thought that say the UK 13amp plug does not handle 13 amps. I believe the Post Office down rated them to 8amps on their properties.

It's not easy to see how a plug which complies with BS1363 (i.e. which can pass the tests specified in BS1363) cannot 'handle' 13A.

Of course, if it's not compliant with the Standard, then anything is possible (and the OP said that there were no CE or BS markings on his one)!

 

[securespark]

There is a BS on the plug - even dodgy-eyed me can see it! To the left of the retaining screw.
It looks like a Masterplug branded plug.

 

[FrodoOne]

No matter what the cause, the plug/pin connection has overheated and the plug et al MUST be replaced.
The overheating has damaged the socket outlet, which now also MUST be replaced.

 

[JohnW2]

There is a BS on the plug - even dodgy-eyed me can see it! To the left of the retaining screw.
It looks like a Masterplug branded plug.

Your eyesight is better than you think (clearly better than mine!), since I could see no marking at all until you moved me to resort to technology, when I saw ...

It still seems very probable that the problem is with either the 'bottom' fuse clip or the rivet connecting that clip - a loose L conductor connection would have resulted in thermal damage at the other end of the fuse.

Kind Regards, John

 

[plugwash]

Either way both the plug and the socket are clearly damaged and need to be replaced.

 

[Oatsie]

Hi All. Thanks for the feedback. I was looking for the CE mark or BS kite mark and missed that it just had the number. The clips were tight, the rivet under the fuse to the top of the plug prong all tight. However, it does look like it is the connection between the fuse clip and the plug prong that was getting extremely hot. Perhaps a substandard rivet or clip. Anyway, replaced with plug and double socket with MK and all fine. Plug gets slightly warm, which is to be expected with 3KW going through it, but does not get hot at all anymore.

 

[SUNRAY]

This damage is not untypical of most brands of BS1363 plugs when run at or near 13A for long periods of time.

 

[Jackrae]

Hi All. Thanks for the feedback. I was looking for the CE mark

A CE mark by itself means absolutely nothing. Unless a specific standard is shown (such as BS...... or TUV.....) then you really have no idea of the quality of the product.

 

[JohnW2]

A CE mark by itself means absolutely nothing. Unless a specific standard is shown (such as BS...... or TUV.....) then you really have no idea of the quality of the product.

A CE mark is meant to indicate compliance with a whole host of EU Regs and standards (which is probably why the mark was invented - to avoid the need to list all those things), but the fact that it is 'self-certified' means that some large pinches of salt are probably required!

In any event, being an 'EU thing', a CE mark obviously does not imply compliance with BS1363 (which is essentially UK-specific), which is why there has to be a BS1363 marking as well as a CE one.

Kind Regards, John