seperate bonding conductor

[ianphilip007]

hi

when running a 10mm bonding( seperate to the cpc proctected distribution circuit) conductor for a pme supply to a detached garage that contains (water/gas services) is it ok to run from exisitng house cu to gargae cu and then bond the services to garage cu. or does the bonding conductor have to be unbroken all the way back to the house cu

many thnaks

 

[sedgy34]

run it from garage cu thats where the potential danger is

 

[telectrix]

if you are using the house earthing for the garage then the extraneous metalwork in the garage needs to be bonded to the house MET ( min 10mm )

 

[ianphilip007]

directly from met to each service ( water, gas,steel framework), or can you run a 10mm bonding conductor to garage cu and then bond garage extrenous conductive parts to the garage cu

 

[Deleted member 26818]

hi

when running a 10mm bonding( seperate to the cpc proctected distribution circuit) conductor for a pme supply to a detached garage that contains (water/gas services) is it ok to run from exisitng house cu to gargae cu and then bond the services to garage cu. or does the bonding conductor have to be unbroken all the way back to the house cu

many thnaks

Yes it is.
The two earth bars in the CUs become Earth Marshalling Terminals.
No the conductor doesn't have to be unbroken back to the house CU, or to the MET.

 

[GLENNSPARK]

directly from met to each service ( water, gas,steel framework), or can you run a 10mm bonding conductor to garage cu and then bond garage extrenous conductive parts to the garage cu

yes...there nothing to say that the seperate 10mm earthing conductor to the C/U in the garage cant be the PME that you export....

 

[ianphilip007]

so if you export the pme to the garage CU via the seperate 10mm bonding conductor would you only earth the supply cable at the house cu and not terminate at the garage cu ???? or just connect the supply earth as well

 

[GLENNSPARK]

i take it your running armoured to the garage..?..yes?....if so then earth the armourings at the house end only......then use the CPC of the armoured together with the seperate 10mm earth cable together...parrallel em up..both ends...into the garage C/Us MET....then take the 10mm earthing cable you exported from there to extranious conductive parts within the garage..(water and gas)......keep it continuous...that is to say you go to the first extranious point...lets say gas....bare the cables insulation off....enough to terminate into a BS951 clamp..BUT DONT CUT IT...KEEP IT CONTINUOUS...then from there to the water...or vice versa...from water to gas...depends which service is nearer to the garage C/U of course...

 

[ianphilip007]

thanks for that advice just wasnt sure about weather you connected the smaller supply earth as well as the 10mm bonding conductor.

 

[GLENNSPARK]

i think theres a sticky on exported PME someware in here Ian....

 

[Deleted member 26818]

One of the problems with using both the armour and the bonding conductor jointly, is that you would have to guarantee that the armour is of a sufficient CSA to withstand the unknown current that may flow in it.
You would also have to guarantee that the circuit conductors would not suffer from the increased temperature caused by the unknown current flowing in the armour.

 

[ianphilip007]

wouldnt use the armour for the cpc or main bonding conductor. would use either seperate 10mm main bonding conductor or use the cpc (3rd core of the swa if 10mm or above) The armour wouldnt have the required csa nessacary

 

[Deleted member 26818]

I would use the armour as a CPC, as that is one of it's purposes.

 

[ianphilip007]

yes solely as a cpc, no problem if its csa is ok. i prefer to use 3 core and use that for the cpc

 

[ses]

You cant export the earth on pme if there is water or gas services in the outbuilding unless you have permission from the energy supplier.
You would install a rod then bond from outbuilding consumer unit
Terminate exported cpc at garage end in plastic enclosure so that the two earthing systems are totally seperate