Anyone know anything about home electrics -help me!
- Thread starter beeboo
- Start date
Time to stop, and get a meter tomorrow.
First turn the dial to 1000V. Black meter wire to earth: red meter wire to red mains wire. Should read ~220 or 240 V
Black meter wire to earth: red meter wire to black mains wire. Should read less than 5V.
Black switch wire should read 0V with the switch off
You should be able to establish which is the switch wire by now.
Now turn the dial to Ω. or "ohms".
One meter lead on each switch wire. (If you put old-style meters in ohm mode across the mains, you could fry them. This one's going to be all digital, isn't it?)
Should read ∞ with the switch off and 0 with it on
danski
Half moon dog
possibly wouldnt advise dare i say, a layman, to go poking around live stuff with a meter.
not that it is in itself dangerous, but just that some of the precautions and stuff someone more savvy knows means they are less likely to say, slip with their fingers etc.
the switch line can easily be found just by checking continuity without the need for power as im sure you know
not that it is in itself dangerous, but just that some of the precautions and stuff someone more savvy knows means they are less likely to say, slip with their fingers etc.
the switch line can easily be found just by checking continuity without the need for power as im sure you know
19sixtysix
Bring me sunshine
Please call an electrician before you kill yourself or burn the house down.
So I bought one of those little continuity tester screwdrivers today. On the principle that if I held the black wire with one hand (electrics OFF!
) and touched the screwdriver the red, if I did that with every set with the light switch on and off, I'd eventually find the switch wire.That's the principle, right?
The flippin' continuity tester lights up even when I just touch a single wire
Boyfriend is currently advocating the idea of trial and error, assume each wire is the switch in turn and we'll eventually find it. Personally I don't like the idea of deliberately wiring things up wrong, even if that's probably what we've inadvertantly done at the moment.
Short of any other flashes of inspiration I'm calling an electrician tomorrow
WouldBe
Dislicksick
'Continuity screwdriver'?So I bought one of those little continuity tester screwdrivers today. On the principle that if I held the black wire with one hand (electrics OFF!
That's the principle, right?
Only things I've seen like that are for testing for live wires and you don't touch anything with your other hand.
'Continuity screwdriver'?
Only things I've seen like that are for testing for live wires and you don't touch anything with your other hand.
like this:
http://www.maplin.co.uk/Module.aspx?ModuleNo=7030&&source=14&doy=Search
maplin said:
Really, by this point I'd agree with 19sixtysix - it sounds like there's something odd with the wiring, 240V will kill you if you let it, and this isn't your field.
Get a professional in to solve the problem.
Ask them while they are there if they can replace your fuses with proper circuit breakers with RCD's.
19sixtysix
Bring me sunshine
Please don't mess about with 240 volts. It sounds like you have managed to wire your switch in parallel with the light instead of in series so switching on the electricity shorts the supply and blows the fuse, but please get an electrician. Your prodding around with a continuity tester is worrying.
Get the electrician deal with the light fitting first before asking them to do anything else. Your fuses seem to be working fine i.e. blowing so its most probably just a matter of the wires being connected to the correct terminals and everything should be ok. A good electrician will have you sorted quickly.
Get the electrician deal with the light fitting first before asking them to do anything else. Your fuses seem to be working fine i.e. blowing so its most probably just a matter of the wires being connected to the correct terminals and everything should be ok. A good electrician will have you sorted quickly.
WouldBe
Dislicksick
Not seen one of those before.
It doesn't specify what resistance will cause it to light though. If you have one of the other lights switched on you could still get continuity through the live wire, light switch (turned on) and bulb to neutral.
If you disconnect all the wires at the fitting (making sure the power is off first) put the tester between the live an neutral wires of each pair in turn and get someone to operate the light switch. The tester should show continuity with one switch position and not in the other position on 1 pair of wires only. Connect this pair with live to the other live wires and the neutral to the bulb and it should work.
gentlegreen
I hummus, therefore I am ...
Those testers are very sensitive - LEDs plus FET I think - at least they're likely to give false positives rather than false negatives.
Bottom line though is to get someone experienced to help you out - you can't rely on standing on insulted steps and the safety trips for ever.
Bottom line though is to get someone experienced to help you out - you can't rely on standing on insulted steps and the safety trips for ever.
gentlegreen
I hummus, therefore I am ...
Do what I do. Hook up a "temporary" supply 
We're getting by without ceiling lights in half the house - we've got enough lamps to make do in most rooms but it's grope-about after sunset in the bathroom. Other half is just taking a shower, not sure how in the dark.
Ha, I just heard a bang, think he walked into something!
Ha, I just heard a bang, think he walked into something!
weltweit
Well-Known Member
I had the same problem with a cieling rose and light switch.
I just replaced the light switch replacing a dimmer with a dimmer and then later with a switch.
But then when I could not get it working I started messing with the ceiling rose and then eventually got myself confused, despite finding wiring diagrams all over the net.
Solution, for me, after a while, I gave up and called an electrician, £50 call out and he fixed it in 15 minutes.
I just replaced the light switch replacing a dimmer with a dimmer and then later with a switch.
But then when I could not get it working I started messing with the ceiling rose and then eventually got myself confused, despite finding wiring diagrams all over the net.
Solution, for me, after a while, I gave up and called an electrician, £50 call out and he fixed it in 15 minutes.
beesonthewhatnow
going deaf for a living
It's taken me several attempts, and a lot of phone calls to my dad, to get lighting circuits sorted in my head. It's not that complicated once you've cracked it, and the trick is to be very careful when you take out old fittings and label everything with tape as you do. Until then though, err on the side of caution at all times, 240V can give you a bit of a jolt to say the least
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