PIR Code1 query

[equitum]

Another contractor had issued a code1 on a PIR against an installation in a small commercial unit, for an overrated protective device:

"32A MCB for 2.5mm PVC/PVC cable" with the recommendation of "Either downrate to 20A or upgrade cable"

(In fact it is a 32A RCBO in a Talisman BT016 Board)

So it sounded like like it was a radial circuit and above seemed correct (Although would you say thats immediate danger and therefore code 1 ??)
I expected to have to replace the rcbo for a 16/20A, however on enquiry these were circa £260 from C.E.F !!!!)

On inspection and test the circuit in question was in fact a ring final, serving a few double sockets, with a spur connected at the consumer unit which may may have given the impression at first glance that the circuit was a radial. (but to my first glance saw the other two phase connectors at the mcb and assumed ring)

Questions are:
i) If it had been a radial would it warrant code 1 (No evidence that the circuit was heavily loaded or likely to be, in fact the opposite)
ii) How would you document the fact you disagree with original PIR ? Issue another PIR ?

 

[Chri5]

i) If it had been a radial would it warrant code 1 (No evidence that the circuit was heavily loaded or likely to be, in fact the opposite)

A raidial on 2.5mm will NOT support 32A, it will support 20A and so the MCB / RCBO should be changed.

Unless it's to a single spur fixed at a lower fuse rating that's that. Who are you to say that the few double sockets don't end up having electric heaters, kettle and high watt load appliances plug in- The potential is there to do so, so the PIR is correct- It's potentially a danger and has been noted correctly.

 

[Chri5]

Talisman are made by BILL I think, here's one on ebay (he has x5)

Would this save you £245

http://cgi.ebay.co.uk/BILL-TYPE-C-3...ryZ26215QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Post back and let me know if its "a goodun"

Oh pumpernickal, you need a 20A- silly me, I'll look further.........

Other than the amin BILL site, can't find anything other than the part number for 20A being THC201S30.

Do any other make fit the 3P CU ??

 

[Lectrician]

New or old talisman? Old if pic above, and the RCBO's are available from DETA - £90

If new talisman, similar to current Eaton, then £40

 

[equitum]

i) If it had been a radial would it warrant code 1 (No evidence that the circuit was heavily loaded or likely to be, in fact the opposite)

A raidial on 2.5mm will NOT support 32A, it will support 20A and so the MCB / RCBO should be changed.

Unless it's to a single spur fixed at a lower fuse rating that's that. Who are you to say that the few double sockets don't end up having electric heaters, kettle and high watt load appliances plug in- The potential is there to do so, so the PIR is correct- It's potentially a danger and has been noted correctly.

But its NOT a radial !!

EDIT: Thanks for looking into replacement RCBO's, appreciated, but as I stated it doesn't need down rating as its actually a ring with a spur from the CU, however I hadn't thought of ebay as a source for such and will consider it in future, so again thanks.

 

[ColJack]

But its NOT a radial !!

then please explain where the other end of the third cable comes back to the the board?
or supply us with details of what the "spur" feeds..

2 cables = ring ( or 2 radials but that's another story.. )
3 cables = 1 x ring and 1x radial..

if all 3 cables are 2.5 then one of them is protected by the 32A and is not suitable..

the PIR is correct..

unless, as stated above, the "spur" only feeds ONE double or single socket outlet, or a fused connection unit, thus limiting the maximum load on that cable.. as per spuring from a ring..

 

[pcboffinuk]

If the third cable is connected to the same mcb as a ring then to comply it can ONLY be serving a single 'point' (single, double or FCU) - otherwise I would say that it needed a separate MCB.

I read it that the single cable was only serving one point, in which case a spur is allowed to be connected at the mcb, but equitum can confirm.

Personally had it been a radial I would have put a code 1, merely because there would be a (small) risk of fire if the cable was overloaded. The risk may be small, but the client should be aware of it (if for no other reason than to cover yourself). That wouldn't mean I would suggest it was left off until corrected, but I would ensure they knew not to plug multiple kW heaters or coolers in.

Re the original PIR, I would suggest that a mistake like this means the rest of the PIR may be questionable so I would suggest carrying out another PIR, but failing that I would issue a sheet of paper explaining the situation, clipped to and kept with the original PIR.

If there is any doubt as to the 'spur' then maybe just stick that on its own 20A mcb or RCBO and complete a certificate for that.

 

[securespark]

Are you suggesting a Ring with a spur at the origin is not safe on a 32A device??

 

[ColJack]

if it's a true spur, in that it only feeds one point of utilisation, then yes its ok..
if, however, it's a radial that has multiple points on it then no, it does not comply..

 

[Spark123]

I have always looked upon it the same way as I would a spur from a ring anywhere in the ring. The overcurrent protection is provided by the plugtop fuse(s), fault current protection provided by in this case the RCBO as long as it fulfills the adiabatic equation for the RCBO on its MCB aspect of operation.

 

[equitum]

Just a single spur to a double gang outlet. To me it doesnt matter where the spur is taken fron, its still a spur

 

[ricicle]

I agree - one 2.5 spur from CU to one DSS is ok.No different to spurring off ring.Assumed max load 26A (but that's another topic )
27A for 2.5 clipped direct.