Zs with a BANG

[Robj63]

Could do with some help with this.

doing a ZS on radial circuit ,doing everything correct but cant understand why the bang , flash and circuit tripping to go with it ( give me a bit of a fright i must admit)

cheers in advance again

Rob

 

[Andy™]

faulty test kit?

 

[ianmacd]

Shorted the test leads?

 

[Manator]

If testing has been carried out in the correct order then as Andy has said it could be faulty test equipment. Double check that the tester is set for the correct test. My testers will not allow me to do some tests if not set for that test but as I do not know which tester you are using I could not comment on some loop tests it is possible to trip but should not bang and flash that indicates a direct short, and should be investigated.

 

[Robj63]

If testing has been carried out in the correct order then as Andy has said it could be faulty test equipment. Double check that the tester is set for the correct test. My testers will not allow me to do some tests if not set for that test but as I do not know which tester you are using I could not comment on some loop tests it is possible to trip but should not bang and flash that indicates a direct short, and should be investigated.

tester is megger 1552

 

[Manator]

Have you tried a two wire loop test I think the megger 1552 can do this test? See if you get any continuity between the test leads with another tester connected to the probes, I do suspect a short between leads, how this is happening I do not know.

 

[steptoe]

Have you carried out all your tests in the correct order?

ie, all your dead tests first to confirm the integrity of the circuit before powering up.

Although I have had a few similar problems with meggers in the past(hence my dislike for them),I thought the problems they had were well sorted by now.

 

[SPECIAL LOCATION]

What sort of radial circuit? lights, sockets, other?

i.e. are we talking a placing of the probes job?

or a plug in adapter of some sort? (lightmates / 13a socket adaptor... )

I presume you get correct polarity lights on you meter before pressing any test buttons?

Does the meter still work in other circuits?

e.g. try a circuit you can test with a plug & socket?

I have known the MCB's in some 6a lighting circuits "chatter" a bit when taking a Zs at fitting?

But not flashy - bango!!!! :|

 

[Robj63]

Have you carried out all your tests in the correct order?ie, all your dead tests first to confirm the integrity of the circuit before powering up.

Although I have had a few similar problems with meggers in the past(hence my dislike for them),I thought the problems they had were well sorted by now.

Thanks for your reply, yes i tested in order, continuity, insulation resistance, etc every thing ok still baffled tester is still working ok as far as i can tell

 

[ian932]

Were you testing in the back of a socket by any chance

 

[Robj63]

Were you testing in the back of a socket by any chance

yes

 

[ian932]

Its possible your live(line) probe hit the earth link on the socket, I've seen it done on some sockets the link between the screw holes crosses close to the terminal screws and if your probe has its sheilds removed they can make contact with L-E at the same time

 

[Robj63]

its possible your live(line) probe hit the earth link on the socket, i've seen it done on some sockets the link between the screw holes crosses close to the terminal screws and if your probe has its sheilds removed they can make contact with l-e at the same time

thanks again ill take a closer look at the socket , by the way it tested ok when plugged in thanks for the tip though ill remember that in future cheers

rob

 

[m4tty]

I've done exactly the above before with my el cheapo Maplin clamp meter. I was testing for voltage at an emergency light key switch and shorted the probe live to metal casing. Certainly woke me up that one did and melted the end of the probe off. I know I should have been using gs38 approved and know it was wrong.

 

[rugbymacc]

maybe due to a poor connection from the test leads to the terminals

 

[Robj63]

i CAN SEE EXACTLY WHAT HAPPENED NOW, JUST HAD THE FRONT OF THE SOCKET OFF IT WAS AS IAN 932 SUGGESTED, MADE CONTACT WITH EARTH PLATE WHILE PROBING LINE TERMINAL THANKS FOR YOUR TIME GUYS

ROB ( WONT MAKE THAT MISTAKE AGAIN)

 

[ian932]

thanks again ill take a closer look at the socket , by the way it tested ok when plugged in thanks for the tip though ill remember that in future cheers rob

If your meter does not come with a 13A plug lead like the Megger MFT does then treat yourself to something like this, saves taking the socket off to test.

 

[Andy™]

If your meter does not come with a 13A plug lead like the Megger MFT does then treat yourself to something like this, saves taking the socket off to test.

he should have a plug lead...

tester is megger 1552

 

[ian932]

[quote name='Andy

 

[m4tty]

i CAN SEE EXACTLY WHAT HAPPENED NOW, JUST HAD THE FRONT OF THE SOCKET OFF IT WAS AS IAN 932 SUGGESTED, MADE CONTACT WITH EARTH PLATE WHILE PROBING LINE TERMINAL THANKS FOR YOUR TIME GUYS ROB ( WONT MAKE THAT MISTAKE AGAIN)

Lol it makes you jump don't it mate . Any chance of a picture of the state of your megger lead now lol bet you weren't pleased by that