Earth Tripping

[twm.bwen]

I have a picture ready to put on but can't work out how the buggery to put in on. I really do appreciate this patience you are showing on this.
I only wanted to change a socket!

 

[JohnD]

try here. It's free.

www.photobucket.com

 

[twm.bwen]

Your quierying of what I called two mains could be due to the fact that the house used to be two seperate properies. Sometime in the seventies (we think) it was knocked into onne, could it be possible that one was kept despite not neing needed and is this anything to do with it?

I still can't work out how to put a photo on despite looking at the FAQs. Sorry guys

 

[twm.bwen]

Hey hey!

 

[twm.bwen]

May be thats why one 100a fuse is painted white and only has a single brown wire connecting it. Maybe the old boy did it himself. I know he was an electrician but thought only the guys from the board were allowed to touch stuff pre meter.

 

[JohnD]

Let's have another pic of the stuff underneath there.

I think there are, or have been, two CUs.

Have you got an overhead supply?

 

[securespark]

Looks like TT to me.

 

[twm.bwen]

Whats TT mean, I think you can tell I know nothing of electrics!

Thanks for staying with me on this, as if its a problem i need to get someone in asap.
Thanks

 

[twm.bwen]

Sorry, yes it does have an overhead supply, and I have an old photo from (presumeably) the 70's which shows the wires entering the structure at either ends of it, but know they both go in one end. Has this old guy done an illegal bodgit (assuming he moved them)

 

[JohnD]

Ah-ha!

Did you turn off the little brown "outbuilding" CU?
(it shouldn't really be necessary... but they share the same RCD and i expect they are both connected to the same earth terminal... .)


p.s. it's a pity they didn't use a bigger CU and junk the brown one and the Henleys

 

[twm.bwen]

Can't remember, will try the whole cenario again once with Out Building CU on and once with it off. Sadly I can't do that tonight, the missus is on her laptop (mains router) doing something and if I do trip the system then I may as well just leave the potential fault and hope it kilss me before she does

I get the impression youg guys are nearly fulltimers with you advice, I hope you're paid cos i really appreciate this. I will post back tommorow.
Thanks and goodnight

 

[securespark]

the trip switch went even though the circuit MCB and the CU RCD were both turned off.

As has been said, the RCD may trip when shorting N > E.

There is no RCD on your CU, only the stand-alone one in the first piccy.

Are you sure the CU isolator was off?

What rating is the stand-alone RCD?

TT is an overhead (mostly, but sometime underground) supply where the cables come into the property without an integral earth connection.

It is up to the consumer to provide an earth rod reading <200 Ohms (100 if you are NIC).

If you have no earth rod, you are at risk, especiially if there is an earth connection via the gas & water pipes. In the case of gas, this has never been allowed and in the case of water has been outlawed since 1966.

If you have no mebs, you are at risk.

If your RCD is > 30mA, your install (if it is TT) is at risk.

If your RCD is 30mA, then your install is not to current standard.
Ideally, you need a s/l board with a min 100mA Time Delay RCD incomer & 30mA on the split side.

However, I would recommend investing a few £££ in a Periodic Inspection & Test Report. This will tell you exactly how the land lies, electrically speaking. Then you'll know what needs doing to bring the install up to scratch.

 

[securespark]

GRRRRRRRRR! John: you really get on mY t*ts when you do that!!

Bummer!

 

[JohnD]

eh? done what? Have I been too quick for you again?

I thought your final answer was very good.

 

[Steve]

Lovin the cheap n nasty CU and the 40 amp 'lectric meter.

But whats with the brown link between the 2 service heads?