Earth Leakage Test

[dsnd_medic]

I've had a few inconclusive IR results on the fluorescent lights I'm testing, they are way too low but everything else checks out OK so I'm sure they are good. If I put a AC clamp meter around the CPC cable going out from the DU what sort of leakage current would I expect to see for a healthy circuit ? 

Thanks in advance for your replies

 

[NozSpark]

When you IR test an installation you are meant to remove/bypass loads like fluorescent fittings, dimmer switches, neons, etc...

 

[dsnd_medic]

If you don't know the answer please don't reply I'm looking for information not waffle.

 

[binky]

you've just been given information that politely suggests your test method is flawed. If you don't disconnect the workings of florries you will always get inconclusive IR test results. As for earth-leakage, basically there shouldn't be any, but unlees you give us a clue, like how many light fittings there are on the circuit an educated guess is not possible.

 

[Steve3948]

Well what are your inconclusive results and does your AC clamp meter go low enough.

What problems are you getting ?

 

[Doc Hudson]

If you don't know the answer please don't reply I'm looking for information not waffle.

If you would like information please provide a full specification of the circuit you are discussing. Cable type, csa, circuit length, number of accessories/fittings, distribution along the circuit, age of fittings, type of ballast / control gear etc, as some circuits may have some natural leakage others may have less. You question is very much a how long is a piece of string. Not withstanding what has been pointed out that control gear for fluorescent lamps should preferably be disconnected during IR testing anyway Chapter 10 of OSG gives guidance.

Doc H..

 

[apprentice87]

"If you don't know the answer please don't reply I'm looking for information not waffle"

Charming attitude.... If you have to ask on here, you should not be doing what you are doing.....

john....

 

[Andy™]

If you don't know the answer please don't reply I'm looking for information not waffle.

with an attitude like that, do you really expect to get any help?

 

[ProDave]

There is no intrinsic reason why a flourescent light fitting should have high earth leakage.  But like everything if it is showing issues you need to test it to find out why, it is most likely faulty.

You don't want to be measuring current through the earth cable. you want to clamp both the L and N and measure the imballance between them (just as an rcd does)

 

[shieldssecurity]

How rude are you. I've never seen such rudeness on this site.

Personally, even if I had an answer to give you, I'd rather give it to some random person in the street. 

 

[Sidewinder]

I've had a few inconclusive IR results on the fluorescent lights I'm testing, they are way too low but everything else checks out OK so I'm sure they are good. If I put a AC clamp meter around the CPC cable going out from the DU what sort of leakage current would I expect to see for a healthy circuit ? 

Thanks in advance for your replies

OP,

You have been given some sound advice, in that if you look at the guidance and requirements in BS7671 & the associated IET guidance what is required with regard to IR testing of installations and current consuming devices.

The guidance to look in the OSG Ch 10, is valid, and this information is also in GN3 Ch.2 & 3.

You would be wise to study these, then come back with the full detail of the circuit, as from here we can't see it!

 

[Marvo]

When you got your inconclusive IR readings what test voltage were you using?

You may get a small amount of standing leakage current from a fluorescent light due to built-in surge arrestors. Measuring the leakage current by clamping the CPC is not a good way of testing, rather clamp the L+N together in your leakage clamp meter then you'll see the total leakage including anything that's going through parallel earth paths.

 

[Chewbacca]

think that's enough pointing out the errors of dsnd-medic. I somehow doubt he will be posting any replies, so I'm locking this topic.

 

[Sidewinder]

Not quite Chewy,

Unless he provides suitable information, he is going to get stupid answers.

There is no getting away from that, sorry.

 

[Chewbacca]

just trying to stop a slaughter :slap

 

[Manator]

I just want to ban the troll, there is no way we should be giving advise to retards like this.

I apologise to all the retards who think they are electricians. We are a friendly forum, but only to those who give and take advise, have genuine questions and understand the advise given.

Forums like ours should be a resource of information and a way of sole traders/electricians to connect with like minded suitably qualified people, not babysitting bad tempered ill informed people like this troll.

Just saying

 

[Chewbacca]

how about we just delete this thread?