Bonding Question Please PIR

Newpark7 · Mar 23, 2011

Hello all,

I had to carry out a PIR today on a new loft extension, original builder went bust no EIC. The loft is being fed via a new RCD CU which is fed via a Henley block leaving a very old Crabtree non RCD protected board feeding the rest of the property, the loft contains one simple room, no extraneous parts etc.

The water service is bonded 6mm, the the Oil service is not bonded at all. The Main Earth conductor is 10mm via a ec15 type clamp fitted to a PILC cable (TN-S) system, this goes to the MET the old board is fed via a 6mm earth from the MET. The new board has a 16mm from the MET.

I have been instructed to PIR the loft ext only.

My question is - as the loft is a seperate board do the bonding/Earth regs of the original installation still have to comply I.E. Main Earth & Bonding be upgraded and oil boiler line bonded?

Any help appreciated as always - Thanks

Newpark7

IQ Electrical · Mar 23, 2011

Newpark7 said:
Hello all,

I had to carry out a PIR today on a new loft extension, original builder went bust no EIC. The loft is being fed via a new RCD CU which is fed via a Henley block leaving a very old Crabtree non RCD protected board feeding the rest of the property, the loft contains one simple room, no extraneous parts etc.

The water service is bonded 6mm, the the Oil service is not bonded at all. The Main Earth conductor is 10mm via a ec15 type clamp fitted to a PILC cable (TN-S) system, this goes to the MET the old board is fed via a 6mm earth from the MET. The new board has a 16mm from the MET.

I have been instructed to PIR the loft ext only.

My question is - as the loft is a seperate board do the bonding/Earth regs of the original installation still have to comply I.E. Main Earth & Bonding be upgraded and oil boiler line bonded?

Any help appreciated as always - Thanks

Newpark7

Yes, when you look at your 'supply characteristics' and 'earthing & bonding arrangements' boxes on your PIR these all relate to the origin of the installation.

Without reporting on these items (which your loft supply needs for A.D.S.) the PIR is worthless.

Use the adiabatic equation for earthing conductor and main protective bonding conductor sizing, it's rather generous.

How does the oil enter the property?

Newpark7 · Mar 23, 2011

Hi

Thanks for that I will do the calcs and see how it comes out - the oil enters under ground through a solid floor, the oil tank is in the garden approx 30 metres from the property, the oil line is 10mm plastic coated copper tube.