ELI at pendant..using long lead

[claire_r]

Hey all, quick question for you.

Did an earth loop at a socket, got 20 ohms which is acceptable as it's on an rcd.

Did another earth loop on a soft test at a light fitting using a long lead l/n at socket and connected to earth at light. The lighting circuit not being on an rcd.

Got 20 ohms again?

Am I reading through the socket circuit by using this method? I would presume I'm testing the earth at the light back to the board and so on but I'm confused as to how I got the exact same reading? This reading not being acceptable if it's not on a rcd.

Any ideas welcome, thanks

 

[Spudnik]

A reading of 20 ohms sounds a bit dodgy to me.

Is the installation TT?

if so, then thats good, but if it isnt, then i think you need to do some investigating.

When testing at a light fitting, you should have all leads connected to terminals in the ceiling rose, not between sockets and lights.

Im surprised the RCD did not trip when you hit the test button.

 

[WarrenG]

Claire could you explain how you are testing the circuits. I understand you are using a pluggin for the socket test but unsure how you are preforming the light test?

Can you tell us what earthing system it is?

As Jason has said, the connection for the lighting circuit test should be at the ceiling rose.

 

[mrloy99]

Hey all, quick question for you.

Did an earth loop at a socket, got 20 ohms which is acceptable as it's on an rcd.

Did another earth loop on a soft test at a light fitting using a long lead l/n at socket and connected to earth at light. The lighting circuit not being on an rcd.

Got 20 ohms again?

Am I reading through the socket circuit by using this method? I would presume I'm testing the earth at the light back to the board and so on but I'm confused as to how I got the exact same reading? This reading not being acceptable if it's not on a rcd.

Any ideas welcome, thanks

Yes your cables should only be connected to your light fitting.I would agree with Jason here that your 20ohms sounds very high.You should investigate the incomming Ze at consumer unit.If you do have TT (usually overhead supply) ALL your circuits should be RCD protected.You should be useing the other set of test leads without the 13amp plug on it.Let us know on your results and we might be able to advise you further.

 

[Spudnik]

I think, Mr G, that she is using maybe a Robin loop tester with the plug and separate earth probe, which is mainly used for checking continuity of bonding etc.

Could be wrong though.

 

[claire_r]

Yes Jason, thats the one, its a metrel multitester...i just plug into a socket and have a long lead to connect to earth at the light.
I'm forever having problems with my earth loops at pendants....being up a ladder, clipping to earth and praying it stays, holding gs38 tips that only just reach the connections and pressing the button whilst trying not to move...nightmare!

 

[Spudnik]

ahhh you just need more practice!

They can be tricky, but you could always get one of these:

Kewtech Corporation | Lightmate | Electrical Testing

We are waiting for someone to buy one and try it before we splash out

Joking aside, i am going to get one soon as they look perfect for testing them pendants!

 

[WarrenG]

About £55 + vat for the set through Napit

Thinking of ordering a set myself

So still a bit amused to how you can do the loop at the light fitting via the socket outlet?

 

[Guest123]

Hey there y'all.

I been looking at them lightmates for a while but I cant bring myself to splash out on them. Main reason being that the low energy pendants that we now have to fit almost everywhere particularly on local authority jobs are those MEM jobbies that only accept the 3 pin bayonet cap pl lamps and they dont make an attachment to fit into those.

As soon as they do I will buy a set, untill then though it's the 3 arm method for me.

So still a bit amused to how you can do the loop at the light fitting via the socket outlet?

Me too Mr G, me too.

 

[Spudnik]

So still a bit amused to how you can do the loop at the light fitting via the socket outlet?

Basically its a quick 'cheat'.

With the Robin tester, it comes with a plug lead and a wander earth probe that when connected to a socket outlet, the earth probe can be used to check continuity on bonding or any earthing.

However, it can also be used to use the plug for LN connection and then probe to light cpc. Hitting the test button will give a result (rcd permitting), but this is not always very accurate.

those MEM jobbies that only accept the 3 pin bayonet cap pl lamps.

My local wholesaler told me that they were not going to produce them anymore.

Pain really because i had loads of pendants and no lamps.

When he gave me the price for the lamps, it was cheaper to get new L/E pendants with lamps.

Oh well.

 

[AlanDavies]

It doesn't sound like your testing the earth loop impedance of the lighting circuit - more the R1 of the socket circuit and the R2 of the lighting circuit

 

[Guest123]

I can honestly say I've never taken a Zs reading on a lighting circuit like that, and never will. Just cant get me head round using L+N of the ring circuit and E of lighting circuit.

 

[mrloy99]

ahhh you just need more practice!

They can be tricky, but you could always get one of these:

Kewtech Corporation | Lightmate | Electrical Testing

We are waiting for someone to buy one and try it before we splash out

Joking aside, i am going to get one soon as they look perfect for testing them pendants!

I use a good old fashioned BC connector for standard pendants.Youse young un's probably havn't heard of them! I don't think they are still available in this country,maybe a car boot sale item.I just have 2 short cables a few inches long terminated in connector blocks.The probe tips are screwed onto other end of connector block.The GS38 tips aren't the best though and I had to cut the plastic back a hair.(the bc connector also comes in handy on building sites for a drill when you don't have a lead,plug into festoon lights)
I also keep a couple of different lsc plugs klik/rock ashby etc.But I havn't come accross a suitable PL connector.

 

[Guest123]

Yeah, I've made my own adaptors for "kliks" and the like, just put a single socket in the other end of the plug flex.

 

[lister]

ahhh you just need more practice!

They can be tricky, but you could always get one of these:

Kewtech Corporation | Lightmate | Electrical Testing

We are waiting for someone to buy one and try it before we splash out

Joking aside, i am going to get one soon as they look perfect for testing them pendants!

You bunch of tight wads, (persumably your not all apprentices?) get them bought, I did and they paid for thier selfs within the first five jobs, I don't know how we ever lived without them, easpecially when fault finding lights to work with rcbo's.
Gives you one hand free to hold your coffee whilst testing- great!