Determine if there's power

Soldato
Joined
10 Mar 2012
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2,985
So my house has 3 lights on the front, 2 on the garage & a PIR on the porch.

They don't work. I've traced the wires back to a switch in the hall but nothing happens. Tracing back from the switch however would mean digging into the walls, which I don't want to do.

Is there a tool/device I can use to check if the wiring has power?

The idea being that if there's no power I'll have them connected to the garage power and stick a smart switch in so I can have them turn on as I get home.
 

Pho

Pho

Soldato
Joined
18 Oct 2002
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9,271
Location
Derbyshire
I'd get a multimeter.

I replaced mine with a Kaiweets HT118A the other year which is really good. All the reviews I read were it's one of the best "cheap" one out there. I'm not an electrician though. Here's a review which really rates it: https://www.youtube.com/watch?v=U7BtLLsrdX0 - I wouldn't cheap out with a super budget one, live mains stings if you accidentally touch it :p

It has a non contact voltage tester built in - so just tap it onto the wire or a wall etc and if it flashes up "H" there's high voltage there. It works surprisingly well.
It also has a live wire mode where you can touch a single probe onto an exposed wire and it'll tell you if it's live
Or you can just do a normal AC voltage check touching two probes onto a live/neutral pair

What I'd do is use the NCV. If it shows voltage there's your answer. If it shows no voltage I'd turn the mains electric off, disconnect the wire from the light (assuming you can), turn the electric back on, and confirm with a proper voltage check as above. I'd never trust a NCV showing it's not live.
 
Soldato
Joined
3 May 2012
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4,832
You don't need to spend £40 on multimeter!!!

I paid about £2.50 on eBay for mine, it's fine.

You only need a posh one if you are using it to test precise resistances over small components. I use it for household and vehicle use it's fine, actually I used it to fix a sensor on my motorcycle and that was testing resistance.

But yes, buy a multimeter.

Don't use those ****** voltage tester pens.
 
Joined
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In a house
I have cheap meters and they work fine.
Also a wand type detector, also works well enough to find live wires in wall, and for a quick check.
I agree that £40 is likely overkill. Provided it's a meter designed for mains usage, at pretty much any price it should be ok.
 

Pho

Pho

Soldato
Joined
18 Oct 2002
Posts
9,271
Location
Derbyshire
Oh the price has gone up. When I bought it there was a discount on and it was £25 which was a bargain with the NCV bits - I end up using them a fair amount for various bits rather than as a one off.
 
Soldato
Joined
10 Mar 2012
Posts
2,985
A multi meter or 2P voltage tester.

You could even use a voltage stick but I don't trust those.

I was looking for a non-contact solution. I know where the wire goes from the switch towards the CU but can't find a connection between the CU and the lights.

It's part of a few electrical issues that need to be fixed, such as the supply to the boiler in the garage. It's on an extension from a socket under the stairs, even though there is conduit as evidence that at some point it was proper wired. But that can wait till it's warmer. For now it works and with 2 kids in the house I don't wanna be needing to disable the heating to re-wire it's power feed.
 
Soldato
Joined
13 Jun 2011
Posts
5,733
I'd get a multimeter.

I replaced mine with a Kaiweets HT118A the other year which is really good. All the reviews I read were it's one of the best "cheap" one out there. I'm not an electrician though. Here's a review which really rates it: https://www.youtube.com/watch?v=U7BtLLsrdX0 - I wouldn't cheap out with a super budget one, live mains stings if you accidentally touch it :p

It has a non contact voltage tester built in - so just tap it onto the wire or a wall etc and if it flashes up "H" there's high voltage there. It works surprisingly well.
It also has a live wire mode where you can touch a single probe onto an exposed wire and it'll tell you if it's live
Or you can just do a normal AC voltage check touching two probes onto a live/neutral pair

What I'd do is use the NCV. If it shows voltage there's your answer. If it shows no voltage I'd turn the mains electric off, disconnect the wire from the light (assuming you can), turn the electric back on, and confirm with a proper voltage check as above. I'd never trust a NCV showing it's not live.

i had that meter. And wouldn't trust it as far as i could throw it! Returned it instantly after getting 4 different resistance readings on a set of leads.

not even having a range setting is infuriating for testing resistance.

However Im used to using more expensive calibrated meters at work so my opinion is skewed. I use one of these for private/home use and just throw it in the calibration cycle with my work meters

Kewtech KT116 Digital Multimeter with Temperature Measurement, Black https://www.amazon.co.uk/dp/B007H8L...abc_1R72WZP759F0PND9AW9V?_encoding=UTF8&psc=1

also those “non contact testers” everyone hates are actually “voltage indicators” and are just used to quickly see if there is voltage not how much. they will indicate on 12v or 600v so for example when opening a metallic cabinet so you should always test properly.
 
Last edited:
Associate
Joined
21 Sep 2020
Posts
1,066
I have cheap meters and they work fine.
Also a wand type detector, also works well enough to find live wires in wall, and for a quick check.
I agree that £40 is likely overkill. Provided it's a meter designed for mains usage, at pretty much any price it should be ok.

They ‘wand’ ones are the ones I refer to as stick type. I hate them, they just aren’t reliable. I certainly wouldn’t be trusting them but each to their own.

I agree, unless you need TRMs and CAT IV don’t spend any money it.
 
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