Security Light Wiring

Did a 'like for like' security light swap last week. Removed the old (no PIR) light, just a red & a black wire coming through garage wall. Volt stick said there was current. Remove fuse.

Fitted new light with PIR, restored power, nothing happened. Checked wiring inside light, still nothing but volt stick still glowing.

Customer then 'remembered' that the old light operated by a switch in the hall, switched that on & all worked fine.

Called me yesterday to say the manual override feature didn't work. With all the PIR lights I've seen, flicking the switch on/off rapidly sends them into manual mode, so they stay on.

I'm assuming that the switch is just breaking/making the neutral - haven't seen the switch wiring yet. Is that a likely cause?

If so, any simple solution, rather than rewire the lot?

Reply to
The Medway Handyman
Loading thread data ...

Hmm, what does that tell you about your volt stick? I suggest you add a proper voltage indicator to your tool kit as a matter of urgency,

formatting link
example. Oh, and the proving unit too, so you can work safely.

You mean "off/on" not "on/off" - i.e. briefly switch off from the on state. Some types require two such cycles (off/on/off/on) to activate the manual override. Yet others require a separate hard-wired switch, in parallel with the PIR's relay contacts. Dare I ask whether you read the instructions?

Further investigation required, using a proper means of voltage indication, not your magic wand...

Reply to
Andy Wade

It sounds like a possible cause. First of all check that the manual mode does work by quickly removing and replacing the fuse. At least that way you know you are switching the live.(1)

If the switch is breaking the neutral it's terminals will show 0V when the light is on.

Find the junction box for the light and wire it up correctly (the JB might be just inside the garage if you are lucky).

Adam

(1) That would not work on the house I went to last week which had a live/neutral reversal at the fusebox!

Reply to
ARWadworth

It tells me that it detects a voltage so I don't get a shock! I have a basic multi meter,

formatting link
would the Martindale unit do for me?

I do mean "off/on" yes, simply a typo. I did read the instructions - see also chocolate teapot. Basically said nothing else other than connect live to 'L' & neutral to 'N'. No diagram, no other info apart from the off/on bit.

Reply to
The Medway Handyman

It looks like it will do less things than Fluke T100. They are about the same price as each other.

Adam

Reply to
ARWadworth

Your volt stick could have been used to check and prove the lack of a nuetral. Had you put the tip alongside the nuetral it would have lit up - indicating the nuetral was actually live, or the unit missing its nuetral connection.

If you run the stick down the outside of a three core flex, you can even check for a missing earth or nuetral - with either one absent, it will be lit up for 2/3rds the time it would normally be lit as it traverses down the flex. With both missing they usually light up for all the distance - all dependant upon the actual twist in the flex.

They are a truly marvellous bit of test gear for initial diagnosis, providing they are backed up with both knowledge and more conventional test equipment.

Reply to
Harry Bloomfield

You do realise those lights don't operate until it is dark, unless you cover the photocell. Why didn't you bother to check with something like a multimeter or light bulb before fitting the new light? Much easier to find a fault and fix it the first time, you must spend ages botching things up, asking what to do here and calling back to the customer. I certainly wouldn't let you touch anything electrical as you have posted a number of questions on how to wire lights and what to do with the wires in the last few months.

Reply to
Pete Smith

They do if you use the overide facility.

We all do need some help and tech advice at times.

Reply to
Harry Bloomfield

Maybe, but it certainly doesn't indicate lack of voltage with sufficient confidence for you to be sure of not getting a shock. Volt sticks can give false positives and false negatives and simply shouldn't be used for anything that's safety critical. If that and a high-impedance multimeter are your only indicators you aren't working safely in accordance with the electricity at work regulations.

formatting link
you isolate a circuit to do some work on it the next step is to 'prove dead' in a reliable manner, and this is where the voltage indicator comes in. Check the indicator first, using the proving unit, or a known live supply, then test your isolated circuit, then check the indicator again.

No instructions about activating override mode? Perhaps it hasn't got one.

Reply to
Andy Wade

formatting link
> When you isolate a circuit to do some work on it the next step is to

May I ask please why a high-impedance multimeter is not acceptable for this? I can see readily enough that it might give some false positives because of induction etc. But if it shows c.230V on a known live, then nil on the isolated circuit, then 230V on the known live again I don't know why it is not to be trusted. (Not an entirely academic question as my only alternative is an old Avo Model 8 and I don't fancy routinely humping that up the ladder. )

Reply to
neverwas

OK, but it's even clearer if the indicator reliably shows close to zero on a dead circuit, so instruments that do are preferred for this application.

The other danger with multimeters is the risk of accidentally connecting them across the mains while on a current range, particularly on a 10 A (or higher) range -- own up, we've all done it. OK if the meter has internal HBC fusing like most of the Fluke range, but definitely not to be recommended on your 5 quid special from Lidl, et. al. Otherwise always use GS38 compliant fused test leads when doing voltage measurements - especially if you want to go prodding around in your consumer unit where the fault level could be quite high - very serious risk of arc flash injury if the test leads blow up in your face...

There's always the good old Drummond test lamp:

formatting link

Reply to
Andy Wade

Thanks - understood (I think).

It's a fair cop 'guv. Another reason I avoid the Avo for checking mains voltages is that leads have perished so I have to rely on several layers of tape.

Reply to
neverwas

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.