A word of caution

Started by texhorse, February 05, 2018, 06:52:18 PM

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texhorse

This "obvious" and "basic" thread is aimed at those like me, who even at 51 years of age is obviously still very naive where electricity is concerned.

Not much is happening on my layout this evening, as I've been blowing my electricity circuit in the house through using too many amps through the layout shed!  I was using a heater in the shed, and its use has put too much current through the house supply.  I came indoors to change the fuse for the fifth time since Christmas, thinking to myself that I really should investigate the cause.

I unplugged the plug from the wall and burnt my fingers on the pins of the plug!  When I opened it up, there's even little scorch marks in there!  Now THAT is scary.

So tomorrow, the heater is going to the tip.  Then I will replace the fuse in the plug again.  We'll see if the power cuts out again.  I am guessing it won't.

The moral of the story is to remember not to try and use too many appliances through a humble household power supply.  My layout, my shed, my house could all have had a disaster.

Andy
UK
:dunce:
Montrose and Highland Railroad
"Gotta Keep Movin' On!"

ntpntpntp

Blimey, what rating is the heater?     A 3KW heater is about the max a plug with a 13amp fuse can handle, but that should still be well within a house ring main circuit's load capacity unless you've got a load more of them on the same circuit.
Nick.   2021 celebrating the 25th anniversary of "Königshafen" exhibition layout!
https://www.ngaugeforum.co.uk/SMFN/index.php?topic=50050.0

themadhippy

sockets are allowed to get hot
Quote, BS1363-2:1995 requires for double socket outlets that both socket outlets have loads applied via test plugs, 1 test plug having a load of 14 amps whilst the other has a load of 6 amps, making a total load of 20 amps on the cable supplying the double socket outlet. The double socket outlet is then subjected to this loading for a minimum continuous period of 4 hours or longer until stability is reached with a maximum duration of 8 hours (stability being taken as less than 1 degC rise within 1 h). The test is passed if neither the terminals / terminations, nor the accessible external surface, increase in temperature by more than 52 degC.
However i'd throw away the plug if its showing scorching and replace with a decent mk or equivalent decent make plug.
freedom of speech is but a  fallacy.it dosnt exist here

Yet_Another

Quote from: themadhippy on February 05, 2018, 07:18:39 PM
sockets are allowed to get hot
Quote, BS1363-2:1995 requires for double socket outlets that both socket outlets have loads applied via test plugs, 1 test plug having a load of 14 amps whilst the other has a load of 6 amps, making a total load of 20 amps on the cable supplying the double socket outlet. The double socket outlet is then subjected to this loading for a minimum continuous period of 4 hours or longer until stability is reached with a maximum duration of 8 hours (stability being taken as less than 1 degC rise within 1 h). The test is passed if neither the terminals / terminations, nor the accessible external surface, increase in temperature by more than 52 degC.
However i'd throw away the plug if its showing scorching and replace with a decent mk or equivalent decent make plug.
That does assume the socket is wired into the ring main, though.
Tony

'...things are not done by those who sit down to count the cost of every thought and act.' - Sir Daniel Gooch of IKB

themadhippy

QuoteThat does assume the socket is wired into the ring main, though.
BS1363-2:1995  doesn't cover the wiring method, thats  down to BS7671
freedom of speech is but a  fallacy.it dosnt exist here

texhorse

All I know is that I'll be working in the shed in Winter with a coat on in future!  Far safer.....

Andy
UK
Montrose and Highland Railroad
"Gotta Keep Movin' On!"

edwin_m

Is the plug rated at 13A?  Occasionally you find 5A rated plugs, there is nothing to stop someone fitting a 13A fuse and using it for a high-power appliance.  This would result in it getting very hot and possibly melting or starting a fire.  The current rating should be marked on the plug. 

davidinyork

One of the most common issues (although it doesn't sound like it's the case here) is over-loading 4-way adapters, or even plugging one into another. The things to particularly watch out for are things with heating elements (fan heaters, kettles, etc), and things with fairly powerful motors (hoovers, drills, washing machines). These should normally be plugged into the wall socket directly, or if an extension lead is used make sure it's a heavy-duty (i.e. 13a rated) one, preferably with only one socket at the end to prevent overloading.

Also, it's advisable to check the rating of 4-way adapters - some are 10a rather than 13a, including the flex, so swapping the fuse for a 13a is a really bad idea as it could lead to the flex melting.

themadhippy

QuoteIs the plug rated at 13A
All BS1363 plugs are rated for 13A,when you see a  3A label it just meens its been  fitted with a  3A fuse
freedom of speech is but a  fallacy.it dosnt exist here

port perran

Quote from: texhorse on February 05, 2018, 07:57:15 PM
All I know is that I'll be working in the shed in Winter with a coat on in future ;)!  Far safer.....
Andy
UK
I'm with you, if it's getting hot then I'd get rid of it.
There's two things I don't trust. Electricity and the wind. And you can't see either of them  ;)
I'll get round to fixing it drekkly me 'ansome.

texhorse

I had a 5 amp fuse in the plug.  I had been assured by an expert that this would be more than adequate for what I used in the shed.  Unfortunately, he was not taking the electric heater into account.

Thankfully no harm done, and I'll be trying again in daylight, minus the heater, and checking the plug to ensure it's not getting hot.

Andy
UK
Montrose and Highland Railroad
"Gotta Keep Movin' On!"

davidinyork

Quote from: texhorse on February 05, 2018, 09:11:56 PM
I had a 5 amp fuse in the plug.  I had been assured by an expert that this would be more than adequate for what I used in the shed.  Unfortunately, he was not taking the electric heater into account.

Thankfully no harm done, and I'll be trying again in daylight, minus the heater, and checking the plug to ensure it's not getting hot.

Andy
UK

A heater will normally have a 13a fuse.

stevewalker

A common reason for an overheating plug is poor contact with the socket - due to spring metal contacts weakening or corroding. It would be a very good idea to replace both the socket and the plug - the heater itself is probably fine.

texhorse

It wouldn't be that Steve.  The shed was only wired to the household supply in October.  I'll rethink what you've said tomorrow after I've tried it without the heater.

Andy
UK
Montrose and Highland Railroad
"Gotta Keep Movin' On!"

stevewalker

Quote from: texhorse on February 05, 2018, 10:29:59 PM
It wouldn't be that Steve.  The shed was only wired to the household supply in October.  I'll rethink what you've said tomorrow after I've tried it without the heater.

Andy
UK

One other possibility springs to mind and is worth checking - especially with it being a new installation. A terminal screw not tightened down properly can give rise to a lot of heating and could be in either the socket or the plug.

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