q: impact of NOT connecting earth to Light connection block
- Thread starter lstoner
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Thanks for the reply.
silly question, but I guess I'm curious ... if I don't get a shock, could I leave it ? And rather than me get a shock, what could I use to test ? ( I have no meter )
On a more serious note, could I run an earth ( just the earth ) from a light terminal in another room ?
silly question, but I guess I'm curious ... if I don't get a shock, could I leave it ? And rather than me get a shock, what could I use to test ? ( I have no meter )
On a more serious note, could I run an earth ( just the earth ) from a light terminal in another room ?
B
breezer
the earth is there for saftey, if / when soething goes wrong the electricity will flow down the earth wire (taking out the protective device as it should)
if there is no earth, and say its you holding the light at the time what do you think the electricty will flow through?
No you can not "borrow an earth" cahnces are that if your light doesnt have one nonr of the others do either. That said it may have ben cut off, but its doubtfull.
This was quite common some years ago, but that also means that the cables are old, and will be in a state of decay.
Your best option would be to get several quotes to get the whole house re wired
if there is no earth, and say its you holding the light at the time what do you think the electricty will flow through?
No you can not "borrow an earth" cahnces are that if your light doesnt have one nonr of the others do either. That said it may have ben cut off, but its doubtfull.
This was quite common some years ago, but that also means that the cables are old, and will be in a state of decay.
Your best option would be to get several quotes to get the whole house re wired
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OK - one last question before I seek an electrician and get quotes etc.
In the last year, we had an extension built - new fuse box, wiring etc to the new build. However, we did not change the wiring in the old rooms ( hindsite is a wonderful thing !) The only way I can see of providing an earth is to run an earth wire of of a neighbouring [new] room light connection. This way I wouldn't have to feed new wire down to the switch - just run an earth from one room to another. Is this a big no no ( as mentioned by breezer ) ?
... and thanks again for your replies.
In the last year, we had an extension built - new fuse box, wiring etc to the new build. However, we did not change the wiring in the old rooms ( hindsite is a wonderful thing !) The only way I can see of providing an earth is to run an earth wire of of a neighbouring [new] room light connection. This way I wouldn't have to feed new wire down to the switch - just run an earth from one room to another. Is this a big no no ( as mentioned by breezer ) ?
... and thanks again for your replies.
OK breezer, just why is this a no-no? I seem to recall it is quite common to interconnect earths on different circuits (i.e. bathroom!).
The important thing is that any equipment which expects an earth actually gets one.
What kind of wiring is in the old part of your house? If it is PVC covered (probably grey) then it is younger than the house is. If it is really 1930s wiring then it would be rubber covered (probably) and very likely falling to pieces. But if it is, then I would have expected the electrician who did your extension to have pointed out that it was dangerous. Good for business and his own personaly liability, if nothing else.
It would not have been unreasonable that your house got rewired 50-60ish with early PVC which did not include an earth on the lighting. This is unfortunate, but not a disaster unless you decide to use metal light fittings/switches. So long as the insulation is ok, then it calls for caution not panic. If the insulation really is rubber and falling off the wires, then you can panic.
The important thing is that any equipment which expects an earth actually gets one.
What kind of wiring is in the old part of your house? If it is PVC covered (probably grey) then it is younger than the house is. If it is really 1930s wiring then it would be rubber covered (probably) and very likely falling to pieces. But if it is, then I would have expected the electrician who did your extension to have pointed out that it was dangerous. Good for business and his own personaly liability, if nothing else.
It would not have been unreasonable that your house got rewired 50-60ish with early PVC which did not include an earth on the lighting. This is unfortunate, but not a disaster unless you decide to use metal light fittings/switches. So long as the insulation is ok, then it calls for caution not panic. If the insulation really is rubber and falling off the wires, then you can panic.
Do you have screwdrivers for dealing with screws?lstoner said:
A hammer for dealing with nails?
A saw for cutting wood?
Why don't you have a meter?
Indeed it is common, but potentially dangerous. I'd never thought about this before, but someone brought it up on the IEE site.Damocles said:
By connecting them together you're providing parallel paths for fault currents. What if one path has a lower resistance than another? Care to think what might happen to the 1mm² cpc of a lighting circuit if it ends up carrying the lion's share of the fault current from a shower on a 50A MCB?
OK - in this case it's all lighting circuits, so no problem there, but generally.....?
ban-all-sheds said:
with the bonding rules for bathrooms you are REQUIRED to interconnect the earths of different cuircuits.
mind you i heared of the following situation once
two flats with seperate supplies (both PME).........
lost neutral to one flat on rec pole.......
single bond between properties earth systems connected to the lighting cuircuit......
melted cable!
as for borrowing an earth from another similarlly rated or higher rated cuircuit its safe enough provided everything remains connected but its definately not ideal because of the possibility of the other cuircuit being disonnected in the future
best to stick to double insulated fittings that don't require an earth
ban-all-sheds said:
there are a couple of important facts here
1: the lighting cable will generally be longer and is very unlikely to be significantly shorter than the shower cuircuit cable.
2: cable of 6 times the CSA (the CPC in 10mm T&E is 6mm isn't it) has significantly less than 6 times the current capacity.
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Forgive me if I've missed something here.
Didn't the poster ask if he could run an earth from a lighting point in another room?
This is OK.
Run a separate CPC to every point in the non-compliant circuit in close proximity to the live conductors in the circuit.
So says the NIC book of snags and solutions - earthing.
This is an alternative to rewiring.
Didn't the poster ask if he could run an earth from a lighting point in another room?
This is OK.
Run a separate CPC to every point in the non-compliant circuit in close proximity to the live conductors in the circuit.
So says the NIC book of snags and solutions - earthing.
This is an alternative to rewiring.
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