230v neutral to earth ? row of lights gone out mcb not tripped

[Hellmooth]

Concur.

 

[Deleted member 72666]

Concur.

Me too!

 

[Deleted member 72666]

L-N voltage was 230v as well and thanks guys . Will have more info after the morning getting there for half 5am . :0 .

What were your findings, do tell?

 

[Deleted member 72666]

Could be in for a long wait I fear!

 

[marlon89]

Hmm ok well my day started off got there at half 5 to give myself some time to inspect as much as poss before people started coming in

Security wouldnt let me in without presence of the site engineer who turned up at half 6 bcos the trains couldn't get him in any sonner even tho we agreed half 5 at the weekend .. lol so my day started well and got better ...

Eventually got in the office and past security , first started taking fittings apart and sensors down and also the circuits have lighting control modules that control all sensors and lights .. but a different company look after them have advised they also come in to check there equipment

Anyway just to clarify for the final time my readings I was getting the first time were 100% correct and at all fittings in was getting 230v L-N L-E N-E

But then I went back to the db to check between earth and neutral bar and was reading around 2v . Also at the mcb that feeds this circuit it has two feeds going in and only one neutral returning . So straight away doesn't look good . When taking one phase out the mcb and testing between earth bar and phase taken out of mcb I was still getting 230v !! So circuit was still live when taken out of mcb but only when that same mcb was re energizer it become live . When switching phases in mcb and turned back on the other phase was reading 120v from cable taken out of mcb to earth bar .

All the fittings have 230v and ballast side and emergency packs ( not all are emergency ) changed lamps but not ballasts and still not working .

Checked all wiring to fittings and couldn't see any cross polarity between switch lives and neutrals between sensors and t5 fittings or any lost neutrals

After further searching for jbs and speaking with site engineer who's been looking after the place for years ! He pointed me to a lighting control module fed from a fuse spur behind a wall in the office corner . Sorry forgot to mention also all fittings have a d1 and d2 connection for lighting control module to be able to dim lights. All connections in module fed from spur seemed to be ok but by this time keen office people started coming in around half 8 and need to start putting everything back together

But I also haven't got the equipment as company won't pay out yet for a fluke tester or multi megger as they are around £€5-600 haha but 1 pr two other engineers have got these testers and 2391 or 2395 as it's called now which I have not yet obtained. Plan to as it's so important for fault finding and hopefully company will agree and help us out abit haha . Doubt it tho .

But yes stil very confused have left circuit isolated as can't be leaving dangerous things like that on without test and inspecting throughout.

Thanks guys . Any ideas what these readings could mean ? As I have never come across this in my 7 years of being a electrician .

 

[davesparks]

You weren't using an approved voltage indicator or test lamp of any kind were you?

You might want to do a little bit if research on capacitive coupling and the associated/resultant phantom voltages before you go much further.

And you might want to advise your customer to call an electrician.

 

[davesparks]

Anyway just to clarify for the final time my readings I was getting the first time were 100% correct and at all fittings in was getting 230v L-N L-E N-E

.

Was that with a multimeter by any chance?

 

[Lucien Nunes]

all fittings in was getting 230v L-N L-E N-E

Any ideas what these readings could mean ?

Yes - your testing method is suspect. SP supply is 230V L-N and L-E, and approximately zero N-E (a volt or two makes no odds.). If the circuit neutral is high-resistance, then the N-E voltage at the load will be higher when under load, but the L-N voltage will be lower, the total always being 230V (but might read less, if the resistance is approaching the input resistance of the meter if unloaded), it's simple physics and not the subject of any mystery. You need to do dead tests to prove the continuity of the conductors. R1, Rn, R2, find the air gap if there is one.

couldn't see.... any lost neutrals

In the land of the blind, the man with a continuity tester is king.

Sorry forgot to mention also all fittings have a d1 and d2 connection for lighting control module to be able to dim lights.

I wonder what other useful bits of information we're missing. I give up.

 

[clubba]

Did you ever get to the source of the problem?

 

[DPG]

Did you ever get to the source of the problem?

Doesn't look like he's been on here for nearly 8 years.

 

[clubba]

Doesn't look like he's been on here for nearly 8 years.

Ok anyone have any ideas I have the same issue???

 

[DPG]

Ok anyone have any ideas I have the same issue???

So you've got 230V between neutral and earth? What other voltage measurements do you have? Have you checked the things that were suggested in this thread.

 

[clubba]

Yes getting 238 at light switches and 108 at light fittings? Nothing tripping but no lights. Looking to see if there is something inline somewhere

 

[DPG]

Yes getting 238 at light switches and 108 at light fittings? Nothing tripping but no lights. Looking to see if there is something inline somewhere

So you have a neutral at the light switches? It might be worth listing the measurements you have taken.

Between which points were the 238V and 108V measured?

 

[timhoward]

@clubba what sort of installation is this? (commerical / domestic etc)
What test instrument are you using?