Fault on lighting cct prevents taking Zs

[Michael J]

Hi All

Taking a Zs from a light switch and am reading 160 volts between L & E.
What would you code this. I think it could be a neutral fault but I don't have the time available to investigate. The location is a hotel room.

 

[westward10]

Before you can Code you need to confirm the cause and effect, if you are doing EICRs this should be knowledge you possess.

 

[Octopus]

C2 - check the earth continuity - bet there isn't any ..........

And as for investigating - that's not really what an EICR is about ...

 

[westward10]

C2 - check the earth continuity - bet there isn't any ..........

The OP should be aware of this if carrying out an EICR.

 

[Michael J]

The OP should be aware of this if carrying out an EICR.

You will have to have a bit of patience with me as up to a year ago the only experience I had of a ring circuit was at 11000v,the last phase rotation test was on a 11000v , 7.4 MW ,slip ring motor and my last-phasing out was paralleling two 5MVA 1100/550V Dyn 11 transformers. The signing off package ran to volumes.

Having said all that I am also autherized to switch 33000V systems.

The OP was aware

 

[MFS Electrical]

You will have to have a bit of patience with me as up to a year ago the only experience I had of a ring circuit was at 11000v,the last phase rotation test was on a 11000v , 7.4 MW ,slip ring motor and my last-phasing out was paralleling two 5MVA 1100/550V Dyn 11 transformers. The signing off package ran to volumes.

Having said all that I am also autherized to switch 33000V systems.

The OP was aware

Don’t you go round wiring up 11kV rings anywhere near me not something I want to come across on a domestic/commercial EICR most of the time someone on here will assume the worst we are all guilty of it with the limited info most OPs give and the amount of chancers we get on here doing their own work and nuggets that don’t know their earth from their a**e

Edit: I’ve never heard that saying before so I’m copyrighting it and making it a trademark don’t steal it

 

[Nigel]

The OP should be aware of this if carrying out an EICR.

I am not sure how this helps anyone.

This could be a standard response to every question.

 

[Strima]

Other test results?

R1+R2?

IR testing?

And out of curiosity why Zs from a switch position and not furthest point of the circuit?

 

[davesparks]

You will have to have a bit of patience with me as up to a year ago the only experience I had of a ring circuit was at 11000v,the last phase rotation test was on a 11000v , 7.4 MW ,slip ring motor and my last-phasing out was paralleling two 5MVA 1100/550V Dyn 11 transformers. The signing off package ran to volumes.

Having said all that I am also autherized to switch 33000V systems.

The OP was aware

That's lovely, but as far as I know completly irrelevant to your original question and any testing carried out to bs7671.
This suggests you have less than a years experience of working on installations at lv and to bs7671, so approximately the same experience as a first/second year apprentice.

 

[TJ Anderson]

Hi All

Taking a Zs from a light switch and am reading 160 volts between L & E.
What would you code this. I think it could be a neutral fault but I don't have the time available to investigate. The location is a hotel room.

Not being funny, but you tested L - E, got 160v, and you think it could be a neutral fault??? How?? You were not testing for a PD across L&N? Unless of course, a PEN conductor was down, but then I would hope you would have noticed other interesting things too lol. Obvs, that last bit was a joke!

As Murdoch has already suggested, you clearly have a floating cpc/earth.

 

[Michael J]

That's lovely, but as far as I know completly irrelevant to your original question and any testing carried out to bs7671.
This suggests you have less than a years experience of working on installations at lv and to bs7671, so approximately the same experience as a first/second year apprentice.

You obviously don't get the joke, lighten up a bit

 

[davesparks]

You obviously don't get the joke, lighten up a bit

Do enlighten us, what is the joke?
You are carrying out an eicr, what is the joke?
Electrical safety at any voltage is far from a joke, if you have a clue you will realise electricity can, and will, kill without any regard for your opinion of whether it is funny or not.

Personally I don't care, but I'm lead to believe that the death of humans is unacceptable?

However I am curious as to how a liver and bacon casserole would taste with hunan liver? I've made it with all of the commonly available livers but humans are somewhat harder to come by for some reason? Perhaps once a few people have died from your approach to electrical safety you could cut out their livers and send them to me, I'll be happy to invite you to dinner to try this particular delicacy.

 

[Deleted member 72666]

Was that last bit strange or what!

 

[Pete999]

Other test results?

R1+R2?

IR testing?

And out of curiosity why Zs from a switch position and not furthest point of the circuit?

Perhaps the switch is the furthest point!

 

[Nigel]

Other test results?

R1+R2?

IR testing?

And out of curiosity why Zs from a switch position and not furthest point of the circuit?

High level lights would be my guess.

 

[Nigel]

Perhaps the switch is the furthest point!

Not sure that is even possible.

 

[Pete999]

Not sure that is even possible.

What that it isn't or can't be the furthest point?

 

[snowhead]

Not sure that is even possible.

Maybe in metres, but not in Ohms.

 

[Nigel]

What that it isn't or can't be the furthest point?

How can a switch be the furthest point?

 

[Norah Nabino]

Hi All

Taking a Zs from a light switch and am reading 160 volts between L & E.
What would you code this. I think it could be a neutral fault but I don't have the time available to investigate. The location is a hotel room.

Out of curiosity why are you quoting the units of zs in volts??
I thought it is measured in ohm

 

[westward10]

Out of curiosity why are you quoting the units of zs in volts??
I thought it is measured in ohm

Yes Zs is measured in ohms but most testers give a voltage indication prior to the test.

 

[Octopus]

Yes Zs is measured in ohms but most testers give a voltage indication prior to the test.

And some testers won't do a Zs test with readings like that ...

 

[Michael J]

That's lovely, but as far as I know completly irrelevant to your original question and any testing carried out to bs7671.
This suggests you have less than a years experience of working on installations at lv and to bs7671, so approximately the same experience as a first/second year apprentice.

I agree with your 1 year experience wrt the UK. I think you should take into consideration my 40 years experience on projects in the mining industry in southern and East Africa, working to the mining regs
I served my apprenticeship(5 years)in the UK. The bit about 11kV etc was me having a hissy fit. (Western10) thought it funny.Sorted out the fault today. I was looking for coding. In South Africa the mines set their own more stringent regs i.e lack of labelling is a C1. So I just wanted to know what the forum thought

Do enlighten us, what is the joke?
You are carrying out an eicr, what is the joke?
Electrical safety at any voltage is far from a joke, if you have a clue you will realise electricity can, and will, kill without any regard for your opinion of whether it is funny or not.

Personally I don't care, but I'm lead to believe that the death of humans is unacceptable?

However I am curious as to how a liver and bacon casserole would taste with hunan liver? I've made it with all of the commonly available livers but humans are somewhat harder to come by for some reason? Perhaps once a few people have died from your approach to electrical safety you could cut out their livers and send them to me, I'll be happy to invite you to dinner to try this particular delicacy.

 

[TJ Anderson]

However I am curious as to how a liver and bacon casserole would taste with hunan liver? I've made it with all of the commonly available livers but humans are somewhat harder to come by for some reason? Perhaps once a few people have died from your approach to electrical safety you could cut out their livers and send them to me, I'll be happy to invite you to dinner to try this particular delicacy.

I think admin need to change your screen name to Hannibal Lector lol

 

[TJ Anderson]

I agree with your 1 year experience wrt the UK. I think you should take into consideration my 40 years experience on projects in the mining industry in southern and East Africa, working to the mining regs
I served my apprenticeship(5 years)in the UK. The bit about 11kV etc was me having a hissy fit. (Western10) thought it funny.Sorted out the fault today. I was looking for coding. In South Africa the mines set their own more stringent regs i.e lack of labelling is a C1. So I just wanted to know what the forum thought

Ok. Out if inteest, Where did you find the broken / disconnected cpc then?

 

[Michael J]

Do enlighten us, what is the joke?
You are carrying out an eicr, what is the joke?
Electrical safety at any voltage is far from a joke, if you have a clue you will realise electricity can, and will, kill without any regard for your opinion of whether it is funny or not.

Personally I don't care, but I'm lead to believe that the death of humans is unacceptable?

However I am curious as to how a liver and bacon casserole would taste with hunan liver? I've made it with all of the commonly available livers but humans are somewhat harder to come by for some reason? Perhaps once a few people have died from your approach to electrical safety you could cut out their livers and send them to me, I'll be happy to invite you to dinner to try this particular delicacy.

I take safety very seriously the nature of my previous work dictates that. The joke was me having a hissy fit wrt 11kV not the fault.
I 'm sorry I brought out the Hanibal Lector in you(that is a joke)

 

[Michael J]

Ok. Out if inteest, Where did you find the broken / disconnected cpc then?

On the cu tightened up all terminals on earth & Neutral bars.

 

[Norah Nabino]

I agree with your 1 year experience wrt the UK. I think you should take into consideration my 40 years experience on projects in the mining industry in southern and East Africa, working to the mining regs
I served my apprenticeship(5 years)in the UK. The bit about 11kV etc was me having a hissy fit. (Western10) thought it funny.Sorted out the fault today. I was looking for coding. In South Africa the mines set their own more stringent regs i.e lack of labelling is a C1. So I just wanted to know what the forum thought

Dont get mixed up with mines regs ,they are completely different from BS7671.
Forget about them and get up to speed with 18th Edition

 

[Michael J]

Completed the 18th it's just that coding is a contentious issue. Some say they will code 2 others will say code three.

 

[Michael J]

High level lights would be my guess.

Where possible I like to use my lightmate and wandering lead

 

[Octopus]

Completed the 18th it's just that coding is a contentious issue. Some say they will code 2 others will say code three.

Is that for a lack of continuity in the CPC?

If so it’s a C2

But it’s up to the person who ordered the report if they want to act on the findings ...

 

[Michael J]

Is that for a lack of continuity in the CPC?

If so it’s a C2

But it’s up to the person who ordered the report if they want to act on the findings ...

Found loose connect at CU fixed there and then

 

[Baddegg]

Not done any eicr’s so apologies if I’m wrong,but why are you repairing things if only doing a report?

 

[Nigel]

Not done any eicr’s so apologies if I’m wrong,but why are you repairing things if only doing a report?

It would take a real arsehole to see a loose connection and not tighten it up there and then. Would also take longer to write the non-conformance so quids up and customer happy.

 

[Michael J]

I will probably be caned by some for this. At the time I discovered the fault I was under the cosh so I wasn't able to find the reason. Today I had a bit more time and luckily the fault was easily rectified. Ironically later on I found a definate Code 1. Which I also rectified on the spot as it was easy. The condition of the installation on the whole is good with the biggest problem being the CUs weren't accurately marked up( circuit description not matching to what was actually installed)

 

[Toneyz]

I will probably be caned by some for this. At the time I discovered the fault I was under the cosh so I wasn't able to find the reason. Today I had a bit more time and luckily the fault was easily rectified. Ironically later on I found a definate Code 1. Which I also rectified on the spot as it was easy. The condition of the installation on the whole is good with the biggest problem being the CUs weren't accurately marked up( circuit description not matching to what was actually installed)

I find it better to start at the intake and work from there.

 

[Pete999]

Perhaps the switch is the furthest point!

Can't see why someone gave a disagree, it is conceivable that the switch IS the furthest point of a lighting circuit, unless of course all the switches are installed under the Consumers Unit !!!!

 

[MFS Electrical]

I think admin need to change your screen name to Hannibal Lector lol

Or at least the avatar

 

[Michael J]

Dont get mixed up with mines regs ,they are completely different from BS7671.
Forget about them and get up to speed with 18th Edition

Just an update, on another forum an inspector found the DBs circuit labelling so bad he gave it a C1, most people give it a C3 from what I gather on this forum. Who is right? Maybe both?

This was on a commercial installation.

 

[Wilko]

Just an update, on another forum an inspector found the DBs circuit labelling so bad he gave it a C1, most people give it a C3 from what I gather on this forum. Who is right? Maybe both

The use of C1 means it must have been an immediate danger, perhaps where machines and isolators are mislabelled which could end in disaster. At home having lights up being lights down is not so much of a concern (must fix that ).

 

[Michael J]

The use of C1 means it must have been an immediate danger, perhaps where machines and isolators are mislabelled which could end in disaster. At home having lights up being lights down is not so much of a concern (must fix that ).

I Agree with you Wilko, circumstances dictate. No hard and fast rules.

 

[Octopus]

I'm assuming that the last inspector didn't actually do any circuit tests!

C1 for no labels ....Pathetic

 

[DefyG]

I can understand the light switch being furthest point from the CU if the light point was also the furthest light point from the cu but there would only normally be a live and switched live return at the switch, No neutral in order to take a Zs reading!
And if so, the furthest point and highest reading would be between the switched return and the neutral AT the light fitting, not the switch.

 

[Strima]

I can understand the light switch being furthest point from the CU if the light point was also the furthest light point from the cu but there would only normally be a live and switched live return at the switch, No neutral in order to take a Zs reading!
And if so, the furthest point and highest reading would be between the switched return and the neutral AT the light fitting, not the switch.

Zs on a neutral?

 

[DefyG]

No not on a Neutral but my meter (3wire device) needs a neutral connection to make the reading.

 

[ukiri]

Then join E & N together , Metrel testers have a double end on one of the probes to do this. Apart from this the OSG shows how to take Zs from a light sw.

 

[DefyG]

Yeah have done that before and you would expect readings to be the same but they weren't.
Does seem more accurate with the N connected, but maybe that's just the meter I was using at the time, when compared with a mates MTF 1552 which had been recently calibrated.

 

[Harry_P]

Yeah have done that before and you would expect readings to be the same but they weren't.
Does seem more accurate with the N connected, but maybe that's just the meter I was using at the time, when compared with a mates MTF 1552 which had been recently calibrated.

In these days of multifunction testers the idea of getting 2 identical test results from 2 seperate tests are long gone. That's the big disadvantage with MFT's