Isolated earth

[Mudassar08]

Hi guys.
New member here i come from Diynot.
Seen a customers kitchen ceiling rose which has 95volts on the earth wire. Its induced voltage from a unconnected cpc. Now the thing is that all the light switches have no earth connection in them except from the kitchens one. Im thinking the earth at the kitchens light is alone without being connected to the earth bar. Now which silly sparky would do that that raises the question. Its a tt but nothing is tripping ofc. Even though its reached the threshold of the elcb trip level Dont know if i should give it a earth or make it plastic.

 

[Fleeting]

How are you measuring this 95v, with what and to what.

 

[poni]

threshold of the elcb trip level

how old is this house?

Its a tt

where in the country is this TT system?

 

[Mudassar08]

How are you measuring this 95v, with what and to what.

With a high impedance meter atm cos i left my other meter at home that day. From the water pipe to the cpc

 

[Mudassar08]

how old is this house?

where in the country is this TT system?

Built in the 30's
Near watford

 

[Murdoch]

best you do dead tests to confirm continuity of the CPC back to the CU

 

[poni]

are you sure its an ELCB and not an RCD

 

[Mudassar08]

are you sure its an ELCB and not an RCD

Lol tt with no rcd or elcb at all. Just some old type 1 mcbs.

 

[Mudassar08]

best you do dead tests to confirm continuity of the CPC back to the CU

Yeah when i approach there, im presuming the guy who worked on this just left the cps at the switch and pendant as all the rest of the lighting had no cpc's what a lazy @ss

 

[poni]

Even though its reached the threshold of the elcb trip level

Lol tt with no rcd or elcb at all. Just some old type 1 mcbs.

which is true?

if its got MCBS then the installation is not as old as the house and should have ELCB at least, they have been around as long as MCBs(about the mid 1960's)

 

[Murdoch]

Yeah when i approach there, im presuming the guy who worked on this just left the cps at the switch and pendant as all the rest of the lighting had no cpc's what a lazy @ss

you are touching it now so it’s down to you …..

 

[Marvo]

If it's a really old installation and it's got steel conduit might it be that the conduit was originally used as the earth system (CPC)?

 

[Mudassar08]

which is true?

if its got MCBS then the installation is not as old as the house and should have ELCB at least, they have been around as long as MCBs(about the mid 1960's)

Totally however when i approached there yesterday i could not find any elcb nor rcd. Its got no glands on the cu. Wondering who even wired this? Imagine cutting grass outside and a fault occurs then your a gonna!

 

[Murdoch]

Built in the 1939’s , rewired in ?

 

[Mudassar08]

If it's a really old installation and it's got steel conduit might it be that the conduit was originally used as the earth system (CPC)?

Ring thats covering the whole property has cpc. Just the lighting is lacking it.

 

[Mudassar08]

Built in the 1939’s , rewired in ?

God knows. This reminds me of seeing 1.5mm sloppy t&e used for the meter tails. Tenant even used that to hang her umbrella

 

[Murdoch]

God knows. This reminds me of seeing 1.5mm sloppy t&e used for the meter tails. Tenant even used that to hang her umbrella

metric or imperial cables ?

sounds like a 1960’s install

 

[Mudassar08]

metric or imperial cables ?

sounds like a 1960’s install

Metric
But this was in another property not this one.

 

[Murdoch]

Metric
But this was in another property not this one.

I meant the house you refer to in your OP

 

[poni]

But this was in another property not this one.

This has got to be a windup!!
first there is an ELCB, then there's not, he don't know if it's been rewired since 1930 or not , PVC or VIR , Singles or T&E, 1.5 T&E tails, don't think so, per 1960 would have been switch fuse box and conduit CPC, not a consumer unit, 1930 would have been glass fronted fuse box with both poles fused,