confused..

terry198920 · Feb 22, 2014

I am only a trainee ( so don't bite too much) a friend of mine called out british gas to fix his boiler.. Whilst he was there he checked the electrics.. Said the earth loop was greater than 200 ohms on the ring main and they should get a spark out asap.. So he asked could i pop down and and have a look before they call in a spark ( to see if i could see what the issue was ) it is a TT supply as far as i can tell with a wylex board rewireable fuses with separate RCD installed.. Tested the board.. 0.28ohms..PFC was 0.956kA.. Tested the rcd at 1/2.. X1 and x5.. All within limits.. Tested the socket where the PLUMBER checked and here is where i get lost.. Earth fault loop impedance Test with a megger1730.. 1st test setting was L-L 0.60.. L-N was 0.60 and the setting l-pe was 800ohms.. Is the setting L-PE the important reading yes? And whats the outcome..

KFH · Feb 23, 2014

I have seen earth rods installed on TNS and TNCS systems. It can be confusing if you are not completly sure of what you are looking for. As has been said 0.28 is VERY low for a domestic TT system unless there a parallel paths e.g. shared metal water pipe with TNCS system bonded next door.

MDJ · Feb 23, 2014

terry198920 said:
Correct i didnt disconnect the main earth for a true ZE..

well then the ZE is not 0.28, you are getting readings from gas and water pipes, start again fella.

ipf · Feb 23, 2014

Confucius he say.......''don't listen to everyone at once, you'll git mixed up, go around in circles and disappear up your own backside''.
Sort out, for definite, whether it's tt, tns or tncs and then you might get somewhere with your question.

telectrix · Feb 23, 2014

this is TT.

shanky887614 · Feb 23, 2014

telectrix said:
this is TT.

View attachment 23205

Some of these guys are mechanics in there day job

cotty · Feb 23, 2014

ipf said:
Confucius he say.......''don't listen to everyone at once, you'll git mixed up, go around in circles and disappear up your own backside''.
Sort out, for definite, whether it's tt, tns or tncs and then you might get somewhere with your question.

I don't know what he's on about but it certainly is not Chinese!!

trev · Feb 23, 2014

KFH said:
As has been said 0.28 is VERY low for a domestic TT system

Nah, I've had 0.29 on a TT before

shanky887614 · Feb 23, 2014

trev said:
Nah, I've had 0.29 on a TT before

Was it that guy who insists on 15m of earthrods that did the install?

trev · Feb 23, 2014

No just little old me and 3 x 5/8 rods. Drove 1 in and got about 100 ohms, knocked the second one in and got 20 ish them I thought how low can you go

terry198920 · Feb 23, 2014

Cheers all!! Am away again this week so will have another go next week providing he has not got in touch with a sparky yet.

cotty · Feb 23, 2014

terry198920 said:
Cheers all!! Am away again this week so will have another go next week providing he has not got in touch with a sparky yet.

Maybe he'll call British Gas back! After all, they wont be away for a week!

terry198920 · Feb 23, 2014

Any idea why they would even be checking the electrics in the first place? After coming out to fix a leaky boiler.

trev · Feb 23, 2014

terry198920 said:
Any idea why they would even be checking the electrics in the first place? After coming out to fix a leaky boiler.

Because the people who come out have sales targets to meet. They semi train them on elctrics and set them loose on an unsuspecting public, as a result little old ladies are coerced into replacing their 16th edition CUs for 17th ones because they've been CONDEMNED! because they're not safe.
Crooks.
I have that on good authority because I have a mate who is a pipe monkey who works for them.

GLENNSPARK · Feb 24, 2014

terry198920 said:
Skelton.. They have recently had a new incoming supply fitted.. The reason i said tt system is because an earth is running outside to a rod.. My first thought was tns if that helps.. I should of took a picture would explain more as to why i got confused.. Im aware the fault is at the socket.. But is it as simple as finding a loose connection and tighten the earths up..

so...any evidence of a TN earthing then?

Knobhead · Feb 24, 2014

trev said:
No just little old me and 3 x 5/8 rods. Drove 1 in and got about 100 ohms, knocked the second one in and got 20 ish them I thought how low can you go

Don’t ask personal questions.