Is this multimeter right for what I need ?

[LeeDowner]

I'm fitting some ceiling downlights in one of my bedrooms, I've located the junction box in the loft that's used for the switching of the upstairs lights.

I need to identify which wires are neutral and which are switched live and that means I need a multimeter ?

I found this one in screwfix, will it do what I need it to do ?

http://www.screwfix.com/p/analogue-pocket-multimeter/14350

 

[ricicle]

For your own safety if you need to ask the question then are you sure you can use it safely and correctly ?

 

[LeeDowner]

For your own safety if you need to ask the question then are you sure you can use it safely and correctly ?

I'm asking the question so that I can use it safely and correctly.

 

[Big Tone]

The simple answer is yes Lee.

It measures A/C voltage and if you turn the mains off at the supply you could try continuity tests using the ohms function. Also, you can use an electrician’s screwdriver, with a neon bulb, to trace live wires.

But, with respect, you need to know what you’re doing. If you don’t then that is the limiting factor; not the right multi-meter etc.

I feel the need for a disclaimer here..

 

[ban-all-sheds]

My that's cheap.

Did you choose that one because it's the cheapest you can find?

This looks ideal for a household starter set - multimeter, voltage indicator and dedicated continuity tester, all in a handy case: http://www.amprobe.eu/de_DE/showproduct/115/Junior-Set/

PDF brochure: http://www.amprobe.eu/de_DE/downloadfile/115/beschreibung_1/

All in German, unfortunately, as is the blurb on each product:

Multimeter: http://www.amprobe.eu/de_DE/showproductdata/487/Hexagon_55/

Voltage indicator: http://www.amprobe.eu/de_DE/showproduct/1672/2100-Alpha/

Continuity tester: http://www.amprobe.eu/de_DE/showproduct/481/TESTFIX/

but it should be available in the UK - the company is now owned by Fluke, contact them (http://www.fluke.co.uk) for info on where to buy.

If not, there are sellers in other parts of Europe: https://www.google.co.uk/search?q=amprobe+("junior-set"+OR+1333)

Right now the English specs are still lurking on the Internet Time Machine from when Beha was an independent company:

http://web.archive.org/web/20060920022629/http://www.beha.com/files_uk/multimeter/93549.pdf


Also see another discussion here: http://www.diynot.com/forums/viewtopic.php?t=26282 It's a few years old, so specific model number advice may be obsolete (and prices will be higher), but the generic advice is still sound.

 

[LeeDowner]

Ricicle & Big Tone: Like it or not some DIY'ers want to have a go at doing their own electrical work. I've done a bit myself but this is the first time I've done lighting which seems more complex than power. I'll never start a job that I don't know how to finish or do properly and that's why I'm here asking questions, I'll ask more questions if I'm unsure about anything else. You don't need to insert a disclaimer and roll your eyes.

Ban-all-sheds: Yes I chose it because it's the cheapest. Anything over £15 isn't an option for something I might only use a handful of times.

 

[Big Tone]

No offence meant Lee, honestly. All I meant was it’s a difficult one to answer and, as is often the case, being there to see it is quite different to posting. But I take your point and criticism. It would be remiss of any professional, I believe, to not point out the high level of risk in a case like this – and that was my only concern. I wasn't 'disin' you, honesly, and I admaire anyone who has a go.

It’s a bit like a problem someone recently had with an amplifier which was blowing fuses. We can recommend what may be gong on from the fault description but it’s no substitute for a qualified electronics engineer armed with a circuit diagram. Or maybe that’s a crap analogy; I don’t know. I’ll get my coat...

 

[ericmark]

As already said yes it will allow a Competent person to do the job in safety.

Likely with main isolator off using the ohm range as the leads will likely not comply with GS38 and be unsuitable for low voltage only being permitted for use with extra low voltage.

However a Competent person could do the job using the light fitting as a test lamp so it's all down to knowledge and skill rather than the meter used.

 

[ban-all-sheds]

Ricicle & Big Tone: Like it or not some DIY'ers want to have a go at doing their own electrical work.

Indeed.

But unlike decorating or plumbing or carpentry or gardening, where blobby paint, wrinkled wallpaper, the odd little leak, crooked shelves, plants which die etc won't kill you, you absolutely MUST NOT do electrical work to lower standards than those of a qualified professional electrician.

Ban-all-sheds: Yes I chose it because it's the cheapest. Anything over £15 isn't an option for something I might only use a handful of times.

I fear that such a penny-pinching attitude to test equipment is incompatible with working to the appropriate standard.

 

[riveralt]

Also, you can use an electrician’s screwdriver, with a neon bulb, to trace live wires.

You are kidding aren't you!!!!!

 

[viewer]

Unless I misread the question, all s/he needs for this task is to identify the cable used as switched live. Slow job on ones own, better with two but completely safe. Power off. Bulbs in. Disconnect each cable in turn, returning it to its original connector as one progresses. Test for continuity across the two conductors. Anything going to lighting circuit /CU will have some sort of reading and it won't change if the switch is on or off. The cable to the switch will show no conductivity when switch is off and good when on. The cheap meter would work even if inaccurate or even not safe at mains voltage due to exposed points etc. Whilst I agree that good instruments are an investment, will be useful in the future and should have been used earlier in the project, I suggest that a £4-50 from Maplin would meet the requirements of this task.

 

[Big Tone]

Also, you can use an electrician’s screwdriver, with a neon bulb, to trace live wires.

You are kidding aren't you!!!!!

Er, yes I thought twice about that one and included it, (as something I have done), but maybe shouldn’t have said it.

Oh come on, don't tell me I'm the only one?

 

[ericmark]

On another forum I set out a sequence of tests to work out which was the switched live using the lamp its self.

I detailed how one could safely put wires in a chock block and by a slow process of elimination work out which wires were which, assuming the standard method of wiring was used.

I was banned from the forum for suggesting a dangerous sequence as it was claimed the DIY guy may not follow my advice to the letter and could forget to switch off the power during one of the steps.

This is of course the problem with any detailed instruction set and with Henry Ford's model T the starting instructions failed to tell the driver to take the motor back out of gear on one of the last steps and if followed to the letter would have run over the motorist with his own vehicle. However there are no records of this happening.

Any wired door bell could be used to "Bell out" wiring to find which pair was the switch wires far easier with clips and sound than watching a meter needle but with a second person working the switch it is easy with any ohm meter.

However isolation is an important part and although as electricians we can often work out when a house is on a TT supply so that only the main isolator will do, to instruct the DIY guy is a lot harder. So to be safe All power should be turned off not just the fuse/MCB feeding the lights.

 

[JBR]

It’s a bit like a problem someone recently had with an amplifier which was blowing fuses. We can recommend what may be gong on from the fault description but it’s no substitute for a qualified electronics engineer armed with a circuit diagram. Or maybe that’s a crap analogy; I don’t know. I’ll get my coat...

Yes. That would have been me.

 

[Big Tone]

It’s a bit like a problem someone recently had with an amplifier which was blowing fuses. We can recommend what may be going on from the fault description but it’s no substitute for a qualified electronics engineer armed with a circuit diagram. Or maybe that’s a crap analogy; I don’t know. I’ll get my coat...

Yes. That would have been me.

Ah yes JBR I don't know if you agree with me here but I am just thinking about what's best to do to help, I hope.

Sometimes, it's possible, that advice on this forum might well be one of caution out of genuine concerns. And that's all I was trying to say, clumsily perhaps.

I know more about electronics and mechanics TBH, (my apprenticeship and decades in the business), and have the 17th edition, but I wouldn't call myself a seasoned electrician.

I do think it is a fair concern to be... careful what advice one gives here. And, I say again, it's not out of disrespect but a genuine concern.

I want a vasectomy and it seems straight forward enough. But I wouldn't say I've got a bottle of JD, a mirror and a Stanley knife - now what do I do?

Just goofin'. I haven't fired my 'live ammo' somewhere dangerous for years... (Too much info).