We’d like to remind Forumites to please avoid political debate on the Forum.
This is to keep it a safe and useful space for MoneySaving discussions. Threads that are – or become – political in nature may be removed in line with the Forum’s rules. Thank you for your understanding.
📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!
Home electrics anyone?
rizla01
Posts: 7,260 Forumite
in Techie Stuff
Hi,
Interesting problem.
I am quite conversant with electrics so the task of replacing existing florries with downlights didn't phase me.
I made the circuit up and left the last connection untill I had isolated the power (As you would) I live in a 1960's chalet which has had an extension added and the prev occupant also had a circuit installed to the garage.
I flicked the fuse switch on the downstairs lights and to be safe, the garage AND upstairs lights leaving just the mains live.
Picked up the switched supply 1.5 T&E and cut it to the required length using (Fortunately insulated) wire cutters, and this tripped the fuse box?
Ok, great, I thought. Some dimwit has taken the lighting for this room from the mains.
Completed the connection anyway to check that it'd work and no problems.
Not believing someone could be THAT stupid I decided to check to find out if, throwing the mains switch would extinguish the lights. Nope!
Tried the various fuse switches and the only one that switched the supply to the upstairs lights is the fuse for the upstairs lights.
Now, I THOUGHT I understood electrics but this one has me baffled.
The one thing that I did note was that the T&E used is the old colours but still grey PVC sheathing. It MAY be that someone used the old wiring (DIY).
ANY THOUGHTS?
Interesting problem.
I am quite conversant with electrics so the task of replacing existing florries with downlights didn't phase me.
I made the circuit up and left the last connection untill I had isolated the power (As you would) I live in a 1960's chalet which has had an extension added and the prev occupant also had a circuit installed to the garage.
I flicked the fuse switch on the downstairs lights and to be safe, the garage AND upstairs lights leaving just the mains live.
Picked up the switched supply 1.5 T&E and cut it to the required length using (Fortunately insulated) wire cutters, and this tripped the fuse box?
Ok, great, I thought. Some dimwit has taken the lighting for this room from the mains.
Completed the connection anyway to check that it'd work and no problems.
Not believing someone could be THAT stupid I decided to check to find out if, throwing the mains switch would extinguish the lights. Nope!
Tried the various fuse switches and the only one that switched the supply to the upstairs lights is the fuse for the upstairs lights.
Now, I THOUGHT I understood electrics but this one has me baffled.
The one thing that I did note was that the T&E used is the old colours but still grey PVC sheathing. It MAY be that someone used the old wiring (DIY).
ANY THOUGHTS?
"Unhappiness is not knowing what we want, and killing ourselves to get it."
Post Count: 4,111 Thanked 3,111 Times in 1,111 Posts (Actual figures as they once were))
Women and cats will do as they please, and men and dogs should relax and get used to the idea.
0
Comments
-
Was it the RCD that tripped? If so, this happens if you short the earth to neutral (when you cut the wire). Residual voltage causes sufficient current to trip an RCD.Apparently I'm 10 years old on MSE. Happy birthday to me...etc0
-
Hi Steve,
Yes it was.
But, worryingly, the wires APPEARED to be blackend too.
Unless I am mistaken. It COULD have been age.
I'll check.
I must admit, I wasn't aware of any blue flash or loud pop. (Done that before:))
Back now!
OK. Got the offcut on my lap now.
There is a small black speck right next to the neutal so what you suggest sounds about right.
Would I have got a belt if I'd bared the wires and touched them?
I take it that the residual is still there with all of the circuits isolated?"Unhappiness is not knowing what we want, and killing ourselves to get it."Post Count: 4,111 Thanked 3,111 Times in 1,111 Posts (Actual figures as they once were))Women and cats will do as they please, and men and dogs should relax and get used to the idea.0 -
Connect up a circuit and voltage tester and check for earth leakage. Tip, NEVER cut a wire without checking for current even if you have turned the power off. Use a detector, the ones you use to check for cables etc in the walls.0
-
Well, I wouldn't recommend licking the wires but no, provided there isn't a wiring fault or error (google borrowed neutral), you shouldn't get a shock off either the earth or neutral, with the fuse removed/ breaker off.
If in doubt though, switch off the main consumer unit switch which isolates both the Live & Neutral.Apparently I'm 10 years old on MSE. Happy birthday to me...etc0 -
Well, I wouldn't recommend licking the wires but no, provided there isn't a wiring fault or error (google borrowed neutral), you shouldn't get a shock off either the earth or neutral, with the fuse removed/ breaker off.
If in doubt though, switch off the main consumer unit switch which isolates both the Live & Neutral.
AHA. I should have mentioned that the switch is a double switch (Two separate circuits).
Would residual cause a small black burn mark (tiny)?
If not then it looks like the symptom could be created by the 'borrowed neutral' that you refer to. Need to lift more floorboards.
Left as is, I assume that this is not a problem that NEEDS to be fixed except for the problem caused when working on the circuit.
Mains off completely, in future, I think."Unhappiness is not knowing what we want, and killing ourselves to get it."Post Count: 4,111 Thanked 3,111 Times in 1,111 Posts (Actual figures as they once were))Women and cats will do as they please, and men and dogs should relax and get used to the idea.0 -
Mains off completely, in future, I think.
Mains off ALWAYS when working with household wiring. You never know how a previous owner, sparky or bodger has wired or mis-wired things.There's love in this world for everyone. Every rascal and son of a gun.
It's for the many and not the few. Be sure it's out there looking for you.
In every town, in every state. In every house and every gate.
Wth every precious smile you make. And every act of kindness.
Micheal Marra, 1952 - 20120 -
Mains off ALWAYS when working with household wiring. You never know how a previous owner, sparky or bodger has wired or mis-wired things.
Good advice!
Previous to me buying this house, someone installed a new boiler, and used the Earth of the 3 core for the switching current from the thermostat.
Move along, nothing to see.0
This discussion has been closed.
Confirm your email address to Create Threads and Reply
Categories
- All Categories
- 352.1K Banking & Borrowing
- 253.6K Reduce Debt & Boost Income
- 454.2K Spending & Discounts
- 245.2K Work, Benefits & Business
- 600.8K Mortgages, Homes & Bills
- 177.5K Life & Family
- 259K Travel & Transport
- 1.5M Hobbies & Leisure
- 16K Discuss & Feedback
- 37.7K Read-Only Boards