Pat Test Question About Tumble Driers

[Pete999]

SO! Did the normal tests, continuity, fine. insulation, fine. Sub leakage.... ( and I would never do this unless I suspected something ) 4.19mA - this still doesnt explain the issue but iirc its meant to be under 3.5mA for stationary equipment?

Are you sure it should be classed as stationary equipment? it's plugged in not hard wired, tried looking back at my notes but it's to wet to go to the shed, your the expert.

 

[bertbuckie]

Not 100% no lol..... but 3.5mA is the max iirc for anything unless it uses an industrial plug.
Again, please please correct me if I'm wrong, i'd rather know.

 

[Adam W]

I can't help thinking you're barking up the wrong tree with all this talk of PAT testing (or rather II&TEE). Measuring the current consumption of the appliance when it's working flat out may tell you something, but I think cogitating over the permissible amounts of leakage current is somewhat fanciful.

It's fair to say the damage to the plug was caused by overheating, which could be caused by overcurrent or a high resistance joint.

I've seen this before, but it was with a commercial washing machine in a hotel laundry being plugged into a 13A socket. The fuse would blow every now and again, but the people who worked in the laundry seemed to have accepted a fuse as a consumable, like a light bulb, which needs changing every now and again. Both sides of the double socket (metal clad) displayed signs of overheating, and they'd run the flex across the floor under a mat so they could use another 13A socket. After checking the power consumption, flex size etc I changed the plug and socket for 16A with a breaker in a separate enclosure and it seems to have been fine since.
This was a commercial washing machine though - I wouldn't expect to have to do this with a domestic appliance, least of all one which comes fitted with a moulded 13A plug.

If there were an overcurrent the fuse would have blown (which you haven't mentioned), which leaves a high resistance joint.
Most electricians will have gone to test a ring final and come across a socket with an abnormally high resistance, plugged the socket adaptor in a few times then found it gives a sensible result. This is because the friction from moving the adaptor has worn away any oxidation on the contacts and it now makes better contact.
Did I read that you plugged the drier in when you bought it and it's been like that ever since? It could be that in an environment where they may be hot, damp air coming out of the drier a layer of corrosion has built up between the socket and plug pin, causing a high resistance joint; in the absence of any further investigation I'd be prepared to put it down to this.

 

[bertbuckie]

Quite possible Adam, thats why I said earlier I couldn't understand the high leakage making any difference.
It is also a condenser drier and not much damp around it tbh, in a well ventilated room but it is possible I guess, strange one to me tho tbh.
It has never popped a fuse.

Just trying it in a different socket under observation so I shall report in 45 mins Bet it gets roasting hot lol

 

[Marvo]

.....I'm in agreement about the neutral tho, very strange.

I don't see why it should be more likely or prone to overheating on the Neutral side.........:thinking:

 

[bertbuckie]

I don't see why it should be more likely or prone to overheating on the Neutral side.........:thinking:

That's what I meant. Running ATM as I had to pop out earlier so will see if it gets hot.

 

[bertbuckie]

Plugs warm, not hot. Cables hot tho.

 

[ohreally]

I find plugtops exhibiting thermal damage tends to be on the neutral pin.

New plug/ flex and monitor the situation.

 

[ackbarthestar]

You CYNIC! :smilielol5:

Try this for a test ........ https://www.youtube.com/watch?v=CfB0Vcft7uA

I suspect the problem is a loose neutral in the socket - Does the socket get warm?

 

[bertbuckie]

So! Thread resurrected, 3 months later and we have THIS!
And to top it off I find this....
https://www.aspokesmansaid.com/shop...ire-after-tumble-dryer-plug-burns-into-socket

Called them, they want to send the same engineer, which I have refused tbh as I find him incompetent. I offered to return the dryer to the shop, but they say this is no use. Where do I stand?

 

[bertbuckie]

And to top it all off, I have young kids, live is VERY exposed ( my 7 year old actually pointed the hole out to me, good lad! )

 

[Risteard]

The first set of pictures shows it on the neutral, but the second set of pictures shows it on the phase.

 

[bertbuckie]

Aye I know, strange eh

 

[bertbuckie]

Possibly just the weak point on either?

 

[Richard Burns]

If you did not change the socket last time then it is very likely this would have happened as the internal socket connections would be corroded already from the previous heat.
In this case however it look like there is a poor connection at the fuse, presumably a slightly dirty fuse or possibly heat transferred along the brass from a poor line connection.

I would change socket and plug and also the cable (as that got hot last time) possibly using a higher csa cable to better handle the current.
However the key part is to have good connections in the socket and plug both in the wiring and on the internal connections of plug to socket.

 

[telectrix]

cheap tat plug and socket IMO.

 

[bertbuckie]

Different socket, I changed it last time

 

[Flanders]

If the tumble dryer was pulling to much load it would blow the fuse i would say it down to poor contact with the fuse in the plug i also noticed that you left tbe card board wiring diagram on the plug the on,y otheridea i can think is that the tuble dryer in running at about 15 amps and the fuse is just hanging on in there , i would recommend doing a load test to see how many amps the tumble dryer is pulling and if its more than 13amp you have a good argument to give to tne suppliers

 

[bertbuckie]

Hi Flanders, the engineer who did the plug from knowhow left the cardboard on lol, I shall try and get an amp meter as I would imagine its towards the end of the cycle it draws the most current tbh.
Someone also said cheap socket and plug... twice ?

 

[Flanders]

Hi Flanders, the engineer who did the plug from knowhow left the cardboard on lol, I shall try and get an amp meter as I would imagine its towards the end of the cycle it draws the most current tbh.
Someone also said cheap socket and plug... twice ?

From my experience every time of have found heat damage like this it been due to loose or poor ccnnection at terminal points , asit was on the neutral on the molded plug and then on the live on the replacement plug , i would say that the molded plug had a bad connection neutral (may of been a comon fault at the manufacturer ,and )the new plug had a bad connection either at the connection or on the fuse holder. If you can take thecover of the plug you may see exactly were the point is , somtimes on cheaper plugs the fuse holder clips never seam very good just my opinion.