Socket tester showing fault

[P123456]

Hi,
So I noticed a burned out socket, the wires also pretty burned, and back of socket was also, I replaced with a new socket.
Put a socket tester on and it was showing a E fault on pretty much all down stairs sockets.
BUT soons I put the oven plug back into its socket the socket tester then shows all green, soons I unplug E fault comes back.
Any idea why everything shows green only when the oven is plugged back in.

Thanks

 

[SJD]

Earth for circuit disconnected, but oven has one e.g. from a gas pipe?

Whatever the reason, you need it looked at, before something unfortunate happens.

 

[P123456]

Earth for circuit disconnected, but oven has one e.g. from a gas pipe?

Whatever the reason, you need it looked at, before something unfortunate happens.

Hi, I've checked every downstairs socket and all earth, live and neutrals all connected, even at the boards everything is connected fine. The oven is just another double socket working off of the downstairs ring main.. soons that's plugged in everything works fine

 

[SJD]

When you say everything connected, how do you know all the E connections are actually connected? Your socket tester is a basic way of testing that suggests they are not, a proper tester (MFT) will check with measurements. E.g. there could be a broken E wire somewhere (such as in a burnt out socket).

 

[P123456]

When you say everything connected, how do you know all the E connections are actually connected? Your socket tester is a basic way of testing that suggests they are not, a proper tester (MFT) will check with measurements. E.g. there could be a broken E wire somewhere (such as in a burnt out socket).

What I done was I switched everything off at the board, checked the board everything in as it should, I then unscrewed all sockets and saw E L N all connect properly, screwed it all back up and switched it on, I plug the oven into the wall socket thsts on thre ring main and socket tester showing green, soons I unplug then fault comes on

 

[SJD]

The action of unplugging/plugging the oven changing the earthing tells you something is wrong which could be potentially dangerous. With a multi-function tester, the earthing can be checked, I suggest you engage the services of someone who can test the circuit properly.

I've no idea exactly why the oven introduces a missing earth, e.g. maybe the casing is touching a gas or metal water pipe. But you certainly can't rely on that for the sockets to be safe!

 

[P123456]

The action of unplugging/plugging the oven changing the earthing tells you something is wrong which could be potentially dangerous. With a multi-function tester, the earthing can be checked, I suggest you engage the services of someone who can test the circuit properly.

I've no idea exactly why the oven introduces a missing earth, e.g. maybe the casing is touching a gas or metal water pipe. But you certainly can't rely on that for the sockets to be safe!

OK no worries, I'll get this investigated.. as for the socket in the other room, it was just the neutral that was burned a d caused a bit of damage to the socket, any ideas what may have caused that? Faulty socket ? Loose connection?

 

[SJD]

Sockets & attached cabling tend to overheat if there are poor or loose connections and a high load (e.g. heater). Can just as likely be N as L.

 

[P123456]

Sockets & attached cabling tend to overheat if there are poor or loose connections and a high load (e.g. heater). Can just as likely be N as L.

OK yeah makes sense I thought that, wo that's unlikely to be anything to do with this fault? As to best honest if the oven was left plugged in, I'd have never suspected the fault as obviously everything would've been showing green

 

[brianmoooore]

This thread illustrates the problem with cheap DIY socket testers! There's something dangerously wrong with your wiring, which was probably present the last time your tester told you everything was OK. If it wasn't for the faulty socket, you'd still be thinking that.

 

[P123456]

This thread illustrates the problem with cheap DIY socket testers! There's something dangerously wrong with your wiring, which was probably present the last time your tester told you everything was OK. If it wasn't for the faulty socket, you'd still be thinking that.

Yeah so if the oven is unplugged it shows the fault, as soons and the oven is plugged back in the fault appears, the oven plugs works off of the downstairs ring main

 

[brianmoooore]

We haven't established just how your oven is modifying the characteristics of your earthing. All that we know is that it is, which, even if it has an all metal gas supply to it as well, should have an extremely minimal effect. Definitely something dangerously wrong.

 

[P123456]

We haven't established just how your oven is modifying the characteristics of your earthing. All that we know is that it is, which, even if it has an all metal gas supply to it as well, should have an extremely minimal effect. Definitely something dangerously wrong.

Possibly the oven pushed back in against the gas pipe feeding a hob and acting as the earth? I could pull the oven out and check if that could be a potential cause

 

[timhoward]

Possibly the oven pushed back in against the gas pipe feeding a hob and acting as the earth? I could pull the oven out and check if that could be a potential cause

It wouldn't actually change anything really. Think of it that the oven is fooling the tester, and the original fault is the same whatever the method of fooling.

Just to reiterate that having functional earthing is a fundamental safety principle. In fault conditions the earthing has to carry enough electricity to blow a fuse or trip a breaker. At the moment, the basic tester is saying there is no path to earth.

With the oven plugged in the tester is detecting a path to earth but your tester wouldn't care whether it's a single strand of thin wire/ just touching a pipe, or a proper earth wire, and it doesn't give any reassurance that the path to earth is any use whatsoever in fault conditions.

Therefore you need a sparks with (expensive) test equipment that can measure how effective the earthing is, and enough experience to diagnose what is actually going on.

 

[Strima]

If the tester is showing no earth on the circuit with the oven disconnected you may well have no earth to the property. I would recommend getting an electrician in as soon as possible to carry out some tests to confirm this.

Can you post a picture of your fuse box, meter and main suppliers fuse?

 

[telectrix]

my money is on no earth to property and the oven being in contact with extraneous metal pipework.

 

[timhoward]

my money is on no earth to property and the oven being in contact with extraneous metal pipework.

Maybe but it would also need to have no bonding for the same path not to exist via MET. Which is entirely possible.
I’d also wondered about a N - E early fault on a heating element completing the loop.