Cause of extension cable plug melting?

pjomara

An extension cable plug melted as so..



The extension cable had a 13A plug and the 3 appliances on it all have 13A plugs. The appliances were a dryer, a washing machine and a fridge freezer. The appliances are all only a few years old, still in their original wiring, house is only 6 years old. None of the fuse box switches tripped and all 3 appliances worked fine when plugged directly into wall sockets.
What caused the plug to melt and how can avoid it in the future?

Mr_Ted

Overloaded, to many appliances on one 13A fuse!
Or possible loose connection?
But I am surprised the fuse didnt blow and a breaker didnt trip, or worse?

All of those appliances should be plugged into seperate sockets!

TimBuckTeeth

The plug has overheated due to a combination of a loose connection and a large current load. From the location of the melting it looks as if fuseholder inside the plug was loose.
You shouldn't run a washing machine or dryer or other heating appliances from an extension lead as although fused at 13A they are cheaply made and can't really cope with that current and are prone to overheating as you have found out.
You should get extra sockets for these appliances added by an electrician.

macman

3 high powered appliances on one trailing 13A extension-it's not exactly rocket science. Tot up the wattage ratings across the 3 devices and see how many watts they're pulling-the 13A fuse gives you a limit of about 3,000 watts. The dryer alone can draw probably 2kW+, similarly the w/m when it's heating.

Norman_Castle

Your appliances should show maximum energy use. Washing machine 2200 watts. Dryer 2500+ watts. Fridge/freezer 250 watts. Nearly 5000 watts through one plug.

molerat

From here http://www.esc.org.uk/fileadmin/user_upload/documents/public/switched_on/SwitchedOn-Issue-18.pdf
Investigation into overloading of four-way extension leads

The national standard for extension leads, BS 1363-2: 1995 , specifies a maximum ‘continuous use’ rating of 13 A for the fitted plug and socket-outlet. The test current is set marginally above this at 14 A for type-testing, to determine compliance with the product standard. Standard BS 1362: 1973 , covering the fuse link, requires the fuse to operate at 1.9 times rated current (that is 24.7 A) within 30 minutes, and also that the fuse shall have a non-fusing current of 1.6 times rated current (that is 20.8 A). It is therefore possible for an extension lead to carry a total current of 20 A for an indefinite period.

In other words it is quite possible to overload, ie overheat, a plug and extension lead without blowing the fuse.

muckybutt

Count yourself lucky you still have a house ! all to often extension lead overloads like this cause house fires and deaths.

Ive been a sparky 20+ years and am still amazed at what I see and how naive some people are towards electricity.

happybiker

As already said, bad connection on a large load.


That was a house fire waiting to happen

Ben84

pjomara wrote: »

What caused the plug to melt and how can avoid it in the future?

You attached too many high wattage appliances to the same extension lead. High wattage appliances like washing machines, electric fires, kettles, tumble driers and such should be plugged straight in to the wall. Ideally not two at the same time on one double outlet either. Meanwhile, extensions and socket multipliers are fine for multiple low wattage things (up to a few hundred watt each) like phone chargers, table lamps and ordinary HiFi/TV/computer equipment.

Also, don't buy cheap extension leads and socket multipliers, the ones I've seen had poor quality contacts and started sparking when plugs were inserted or removed after a few months of use. Brands like permaplug and masterplug seem to be fine however.

muckybutt

Ben84 wrote: »

Brands like permaplug and masterplug seem to be fine however.

To be honest Ben ive even seen them melted beyond recognition both plugs and the trailling sockets.

If I were to give one bit of advice - never use heating appliances on multi way extensions.

Blackpool_Saver

scary what people do, and how they won't listen to advice either