Eicr coding

[Guest55]

Sockets are a ring main 2x line 2x neutral and 2x cpc however the cpc is trunking as one leg and single as the other leg.
Now all the sockets are taken from the metal trunking in plastic conduit so at each socket outlet the is only one cpc not two as no path through the plastic conduit

theres something very wrong about this set up.
either youve incorrectly identified the cpc system or the design is a complete lash up.

if youre using metal containment for multiple circuit cpc , thats fine , so long as Zs complies for each individual circuit relying on the trunking for earthing then theres nothing to code.
But if thats how its to be done then i'd like to see totally connected
steel conduit drops to switches and sockets , not a mash up of steel and pvc , thats asking for trouble.
and if you want to use seperate cpc's for the rings , thats fine , but do it as a proper loop , 1 in , 1 out as you would with t&e , cant see how you can effectively use only 1 cpc and the trunking which is linear in its route.

seems "odd"

 

[ses]

2.5mm cpc at each outlet

 

[ses]

Yes thats what i thought
All zs are low,
R2s are very low as well

 

[Guest55]

All zs are low,
R2s are very low as well

then theres nothing to code , all values comply.
just put it down to a"weird" install and move on.
i guarantee you'll find worse things in the course of the inspection.
;-)

 

[KAS1]

Recommend as biff indicates "metal conduit drops" or 6mm cpc in plastic conduit bolted to metal trunking and code C3 (only a c3 if all Zs values are within limits) c2 if zs values are to high. Mind you I might change my mind in the morning lol

 

[ses]

Oh i have yes

 

[ses]

Ok thanks for help
I will recheck on monday when im back just in case i missed anything

 

[oldtimer]

Remember the 14th edition Electrically and Mechanically sound why because earths were never run as the containment was an earth . Noticing more often on this forum where people freak out when there is no earth. But I don't see the problem with it so you cannot fail it as that was the standard at the time

 

[Guest55]

Ok thanks for help
I will recheck on monday when im back just in case i missed anything

first thing i'd do is find out exactly where this 2.5 cpc starts and finishes.
if its not at the db i'd be recommending a new cpc leg be installed to each skt.

 

[Guest55]

Remember the 14th edition Electrically and Mechanically sound why because earths were never run as the containment was an earth . Noticing more often on this forum where people freak out when there is no earth. But I don't see the problem with it so you cannot fail it as that was the standard at the time

the problem is that pvc has been incorporated into the containment so not a continuos metal system

 

[ses]

Thanks biff

I wasnt freaking out with the no earth i was just asking if the containment system could provide earth to all circuits.
I appreciate all help advice and it doesnt hurt to check other peoples opinions on things.
When testing an installation as big as this 5 supplies over 500 hundred circuits its easy to miss things or look to much into things

 

[ses]

Its very odd when measuring cpc to metal trunking i got around 0.17 ohms suggesting thats a ring yet 1cpc at every socket suggests different unless somehow spured down from inside the trunking maybe

 

[Guest55]

was just asking if the containment system could provide earth to all circuits.

the csa of 100mm x 100mm trunking is 324 sq. mm.*
so that would be a yes.
;-)


* took me 5 seconds to google that.

 

[ses]

I should get more up to speed maybe

 

[GLENNSPARK]

Thanks biff

I wasnt freaking out with the no earth i was just asking if the containment system could provide earth to all circuits.
I appreciate all help advice and it doesnt hurt to check other peoples opinions on things.
When testing an installation as big as this 5 supplies over 500 hundred circuits its easy to miss things or look to much into things

well...look at it from this point of view:
mate of mine has a mill with a steel trunking that runs on both sides of each floor which is also used as the fault path...this has various connys coming off it that drop down to points (both lighting and power)....some single phase...others 3....
so whats the prob?
i think you`l find that the trunking will give a lower impedance path as well than any cores likely to be pulled into it...
i just cant get this `thing` that seems to do the rounds about containment being used as the CPC...
theres some that may argue the case for a G/Y conductor to be pulled in so if theres an interruption (damage to the containment)....but its not necessary...
surely as any damage to containment would be duely reported as well...
and this would/should be the case for those PVC conny drops...
do the adiabatic on the G/Y in them PVCs if your not sure (although i think you`l find `em ok)...