Can someone tell me which system this is?

Dave0098 · May 31, 2009

hello, im just wanting to confirm that this system is TN-C-S. i know which systems are which when looking at them on paper but identifiying them at the source i dont really get involved with that.

here is a picture of the set-up.

neutral conductor on the left

phase conductor in the centre

Earthing conductor top right

anyway i think this is a TN-C-S.

thanx for your replys in advance.

Cheers Dave

Spudnik · May 31, 2009

Please tell me that isnt the incoming supply!!

If it was PME then a label would be fitted.

If it isnt, then i would say TNS.

Did you do a Ze?

Dave0098 · May 31, 2009

yes, this is.

lol

Guest123 · May 31, 2009

Looks like they've pinched a couple of strands off of the neutral to use as earth

Dave0098 · May 31, 2009

so what do you think jason?

yeah i thought that but like i said i dont really get involved with this that much so i just thought nothing of it.

i didnt do any Ze test, ive not got up2 testing the install yet. i was just taking a photo of it to post on here to comfirm the system so i can put it on my cert when i start testing.

also the main fuse was a 40amper.

Spudnik · May 31, 2009

Hmmm i would hazard a guess at tncs but the Ze test may prove otherwise.

To be honest, as long as all the circuit tests are within limits then i would not be overly concerned. Just make a note on the cert.

And may i ask why you have taken the whole cutout apart?

Dave0098 · May 31, 2009

well the bottom half was the fuse holder, i took this out but it did not expose the incoming supply cable where the conductors are seen for their set-up, so i removed the top half of the unit to expose this so that i could see the configuration of the conductors.

if thats what you ment jason?

Spudnik · May 31, 2009

To be honest Dave, you should not under any circumstances remove the head assembly covers.

Fuses maybe but not that.

Now having looked a bit closer i would say TNS as this type of cut out is not normally used on PME.

GET THOSE COVERS BACK ON!!!!!!!!!

Dave0098 · May 31, 2009

totally understand where ur coming from jason, thx for ur concern. the covers are all back in their positions and will not be coming off again. i only took them off as i could not see the configuration of the supply and i wanted to make sure of that by providing a photo for you to see and the only way i could do that was by removing the cover.

cheers dave

Spudnik · May 31, 2009

Fair enough mate.

Do some tests and let us know what you find.

Mac · May 31, 2009

Dave0098 said:
hello, im just wanting to confirm that this system is TN-C-S. i know which systems are which when looking at them on paper but identifiying them at the source i dont really get involved with that.

here is a picture of the set-up.

neutral conductor on the left

phase conductor in the centre

Earthing conductor top right

anyway i think this is a TN-C-S.

thanx for your replys in advance.

Cheers Dave

Is this in your house mate.Looks very dodgy.I'd call the the DNO

Dave0098 · Jun 1, 2009

cheers jason, thanks for your info, i will get back to you when i have done some tests.

Dave

no this is from a shop i am working in at the moment, im doing this job for some friends who are starting a catering shop up.

thinking back there is only a 40 amp fuse at the mains. ive already pulled in new cable for 2 cookers and a ring main, the other circuits already existing are a couple of lighting circuits, a boiler circuit, and probably a radial could b 2 radials im not 100% on that.

not using diversity 40 amps doesnt make me think that will be enough for the whole install?

thinking back the tails looked to be 12-16mm from the main incomer to the consumer unit. what if the supply isnt enough for the new install? will the electricity board be able to upgrade it and will it incur a cost?

cheers Dave

kung · Jun 1, 2009

Dave0098 said:
cheers jason, thanks for your info, i will get back to you when i have done some tests.

Dave

no this is from a shop i am working in at the moment, im doing this job for some friends who are starting a catering shop up.

thinking back there is only a 40 amp fuse at the mains. ive already pulled in new cable for 2 cookers and a ring main, the other circuits already existing are a couple of lighting circuits, a boiler circuit, and probably a radial could b 2 radials im not 100% on that.

not using diversity 40 amps doesnt make me think that will be enough for the whole install?

thinking back the tails looked to be 12-16mm from the main incomer to the consumer unit. what if the supply isnt enough for the new install? will the electricity board be able to upgrade it and will it incur a cost?

cheers Dave

No Dave the DNO wont charge ! as said give em a bell and tell em what you want eg max demand and they will book it in with you they might put 3ph head in as catering may need over 100A that way gives opt to block ph's ie blanks and give 100/200/300A just by replacing blank with fuse etc.
Regards
Kung.

OilBeDamned · Jun 1, 2009

Dave0098 said:
hello, im just wanting to confirm that this system is TN-C-S. i know which systems are which when looking at them on paper but identifiying them at the source i dont really get involved with that.

here is a picture of the set-up.

neutral conductor on the left

phase conductor in the centre

Earthing conductor top right

anyway i think this is a TN-C-S.

thanx for your replys in advance.

Cheers Dave

Looks like a TN S system used with split concentric cabling. Hence why it looks like they have pinched strands from the neutral for the earth.

If it was TN-C-S all the cores would go into the neutral with a link going from the neutral connection to the earth block.

Contact the supply authority as your incomer may require upgrading dependant on load, you may also need to upgrade your tails from the cutout and the earth block.

Dave0098 said:
so what do you think jason?

yeah i thought that but like i said i dont really get involved with this that much so i just thought nothing of it.

i didnt do any Ze test, ive not got up2 testing the install yet. i was just taking a photo of it to post on here to comfirm the system so i can put it on my cert when i start testing.

also the main fuse was a 40amper.

kung said:
No Dave the DNO wont charge ! as said give em a bell and tell em what you want eg max demand and they will book it in with you they might put 3ph head in as catering may need over 100A that way gives opt to block ph's ie blanks and give 100/200/300A just by replacing blank with fuse etc.
Regards
Kung.

Just seen these posts tails will definately need upgrading and so may the actual split concentric.

Will be a minimum 80A fuse installed.

Unless the house is huge with a huge load I dont really see why they would upgrade to a 3ph head, upgrading to 3ph may incur a cost dependant on company as they may charge you for the digging of the road and the jointer to do the cable joint.

Dave0098 · Jun 1, 2009

hey thanx for the replys, so how do i go about getting in touch with the DNO? sorry if i sound daft, but i dont really get involved with this, but what do i say to the DNO, something like "the supply for the shop is not adequate for the install and needs upgrading to be able to take the load" ? also the shop is leased to these people im doing the work for, would you think the owner needs making aware that the supply needs upgrading?

is there a number for the DNO in my area Marske, cleveland.

cheers Dave

Mr Mark Sparks · Jun 1, 2009

i would call them and tell them its a dangerous situation that way it will get sorted quickly
if they say its not dangerous when they attend you can just say "you were doing your job by calling"