Soldering iron tripping RCD

[Whiskers]

I was just about to unsolder my motor to test it on another speed control when as soon as I touched the iron to the joint the RCD in my house tripped. I reset it and it tripped again this time as soon as I switched the iron on. The thing is it only does it in the socket with the cooker switch not any of the other sockets. Do I need to bin it and get a new one?

[Cardnim]

If your cooker is on (even in a standby mode) then the amps draw across the fuse of both your cooker and soldering iron will cause the RCB to kick in.

What W is your iron?

[Whiskers]

Its a 40w iron but iv'e just tried it in a couple of other sockets and it trips in them as well. Its just weird how it doesn't do it in a certain socket even thought they should all be on the same circuit as the house was rewired only last year!

Also its not tripping the cooker circuit its tripping the RCD for five circuits

[Cardnim]

Hmmm, if its happening on switches other than your cooker then thats weird.
Rather than jump to the worst case scenario and say something is wrong with your house electrics, its more likely that something is wrong with the iron itself (a dodgy cable could short out sometimes, but not others, giving the impression that it works in some sockets, not others)

Question: Do I understand you right that your cooker AND other sockets are going to the same fuse/RCB?!

[Whiskers]

Originally Posted by Cardnim

Hmmm, if its happening on switches other than your cooker then thats weird.
Rather than jump to the worst case scenario and say something is wrong with your house electrics, its more likely that something is wrong with the iron itself (a dodgy cable could short out sometimes, but not others, giving the impression that it works in some sockets, not others)

Question: Do I understand you right that your cooker AND other sockets are going to the same fuse/RCB?!

No separate fuses same RCD (residual current device)

[Cardnim]

Ahh right, no worries.
As long as they arent all going into one RCB (circuit breaker)!

p.s. weird to have an RCD in a house. Maybe its standard now, I cant keep up with all the building regs, but when I was studying, an RCD was to stop people from getting electrocuted and thats its only use.

Anyways... back to the soldering iron. I'd look for a fault with the iron itself.
Can you plug in your kettle to the same socket as the iron is tripping out on? Turn the kettle on - this is a fairly high drain and if it doesnt trip out, then its the iron.

[Whiskers]

Originally Posted by Cardnim

Anyways... back to the soldering iron. I'd look for a fault with the iron itself.
Can you plug in your kettle to the same socket as the iron is tripping out on? Turn the kettle on - this is a fairly high drain and if it doesnt trip out, then its the iron.

Just tried this and it boiled no problem. I guess it's time for a new iron then which is a bummer as I've only had this one less than 6 months but it was only £10 from maplins!

[Cardnim]

Open up the plug and cable if you're confident.
You might find a broken/touching wire that is causing the problem?

Stick with 40W if you have to replace it, thats a good power for the rc stuff.

Good luck buddy

[Whiskers]

Already opened up the plug but everything is fine. Looks like it is only fit for the bin.

P.s I have just finished my electrical installation course so am very confident with these kind of things lol!

[Cardnim]

lol.
Ever get the "trying to teach your granny to suck eggs" feeling

Cut and strip the moulded plug at the iron end too.
The problem could be in there.

[Whiskers]

Originally Posted by Cardnim

lol.
Ever get the "trying to teach your granny to suck eggs" feeling

Cut and strip the moulded plug at the iron end too.
The problem could be in there.

Do you mean disassemble the iron or cut the cable off?

[Cardnim]

You know the black moulded rubber piece where the cable goes inside the iron itself?
Cut it open with a scalpel (carefully to avoid cutting the wires) and it should come away from the iron (you might need to pop open the iron halves to fully get it out)
With the wires exposed, see if you can see the problem, if not, Id give up there.

[Whiskers]

Originally Posted by Cardnim

You know the black moulded rubber piece where the cable goes inside the iron itself?
Cut it open with a scalpel (carefully to avoid cutting the wires) and it should come away from the iron (you might need to pop open the iron halves to fully get it out)
With the wires exposed, see if you can see the problem, if not, Id give up there.

The one on my iron has holes in it and I can't see anything through it so it must have melted something inside the iron as I was using it for a good few hours yesterday.

[Cardnim]

You mentioned you got it in Maplin.
Is this it:
http://www.maplin.co.uk/40w-soldering-kit-399593

[Whiskers]

Originally Posted by Cardnim

You mentioned you got it in Maplin.
Is this it:
http://www.maplin.co.uk/40w-soldering-kit-399593

That's the one

[RudolfXC]

The cooker outlet and its 13A socket may not be on the same RCD as other sockets as it will have its own MCB (Circuit Breaker). If the house is recently wired, all sockets need to be on an RCD and it is advisable to also put lights on one so the upstairs lights and downstairs sockets go on one and the downstairs lights and upstairs sockets go on another so you will have some lighting and some sockets working if one RCD trips.

Now to the soldering iron. The iron tips are earthed for safety. If any of the ceramic enclosing the element gets damp or breaks down, you can get a small current leakage to the outer metal which will trip an RCD if 30mA. But, RCD have a tolerance so the iron could have a leakage of 25mA, and one RCD could trip at 20mA and another at 30mA so the iron would only trip one of them.

In any case, it looks like the iron is broken.

[Cardnim]

There ya go. Much clearer than my blatherings

(An RCD still seems like a strange thing to have in residential developments as its only designed to trip on current leakage as far as I know)

@Whiskers - this is the rubber piece I was talking about cutting through. If you dont have this, then something very wrong has happened, and Id ditch the iron

[Whiskers]

Originally Posted by Cardnim

There ya go. Much clearer than my blatherings

(An RCD still seems like a strange thing to have in residential developments as its only designed to trip on current leakage as far as I know)

@Whiskers - this is the rubber piece I was talking about cutting through. If you dont have this, then something very wrong has happened, and Id ditch the iron

Yes it has that but i don't see any point in cutting through it as it has holes already in it.

[Whiskers]

This is sort of what my consumer unit looks like. It is the RCD in the centre that is tripping all the fuses are fine.

[teambowen]

Originally Posted by RudolfXC

The cooker outlet and its 13A socket may not be on the same RCD as other sockets as it will have its own MCB (Circuit Breaker). If the house is recently wired, all sockets need to be on an RCD and it is advisable to also put lights on one so the upstairs lights and downstairs sockets go on one and the downstairs lights and upstairs sockets go on another so you will have some lighting and some sockets working if one RCD trips.

Now to the soldering iron. The iron tips are earthed for safety. If any of the ceramic enclosing the element gets damp or breaks down, you can get a small current leakage to the outer metal which will trip an RCD if 30mA. But, RCD have a tolerance so the iron could have a leakage of 25mA, and one RCD could trip at 20mA and another at 30mA so the iron would only trip one of them.

In any case, it looks like the iron is broken.

i agree with the above. The RCD is working as it should and your cheap iron has had its day.
Very strange the same thing happens to your cooker.
I would say one of your heating elements is on it's way out aswell fella.