Proving dead at the CU

[ringer]

Can you use main incoming L&N as known voltage source instead of a proving unit?

 

[IQ Electrical]

Yes, I do it on every annual assessment and you're confirming supply polarity at the same time.

 

[ian.settle1]

Can you use main incoming L&N as known voltage source instead of a proving unit?

I wouldn't as what if your test lamp said it was dead and it wasn't because you have a duff test lamp?

 

[IQ Electrical]

I wouldn't as what if your test lamp said it was dead and it wasn't because you have a duff test lamp?

How is that scenario improved using a proving unit?

 

[Amp David]

Think if you tested on the incomming side of the main switch and you had no voltage, then surely you'd realise your test was dead anyway or theres a power cut in the areaLOL

 

[Adam W]

If the lamp fails to light on the outgoing side of the main switch you should then prove the tester, ie it should light on the incoming side (or in a proving unit).
If it doesn't, either your test lamp is broken, or as already metioned, there's a power cut.

 

[Des 56]

Can you use main incoming L&N as known voltage source instead of a proving unit?

Never seen a proving unit and certainly never owned one

There is no better way of first proving your meter actually works than by shoving it onto the national grid
Then theres no better way of deciding a circuit is live or dead, than by using that same meter to give you many more days of sparking without burning those pinkies

 

[Deleted member 19807]

I have done this on every assesment i have had and its always been ok, and i have a proving unit for when not at tha cu.

 

[Jimmy Boy]

A proving unit lights up if working. I guess if you wanted to Mr health and safety you could argue using the incoming main to do an initial proving could be classed as 'Live working' and classed as unnecessary as other means available, and secondary testing for voltage is necessary to prove isolation..Food for thought

 

[Deleted member 19807]

if you are doing the ze test you have no choice then to work live so you might as well do the proving at the cu when testing for a dead cu to perform r1r2 tests ect.

edit my proving unit don't light up, my voltage tester dose.

 

[IQ Electrical]

if you are doing the ze test you have no choice then to work live so you might as well do the proving at the cu when testing for a dead cu to perform r1r2 tests ect.

edit my proving unit don't light up, my voltage tester dose.

My proving unit has no 'lights' either!

 

[thewetspark]

I have a proving unit but mostly use whatever is available and close, the idea is to "prove" your tester is working, if it doesn't come on when you expect it to then you have to get something else to test that supply with, even if that supply is your proving unit. Meter tails are great but if my Martindale said they were dead I'd still check them out again with something else before I got hold of them. It's about safety so you have to "prove" your tester before and after you test something is dead. The book says with a "known" supply, you only "know" its a supply if the tester comes on.

 

[Jimmy Boy]

My Marty lights up

 

[Deleted member 19807]

no, you know its dead because you prove your tester not the supply. thats what a proving unit dose

 

[ringer]

So if you're up for assessment, and you're working on a CU, and you have to hand a readily available 'known source'. But if you don't own a proving unit, is the assessor going to say 'what happens when you're not at the CU, how will you prove dead if you don't own a proving unit?'?