Quick bonding question

[Von Vardo]

Went to a job today where the boiler is in an outhouse. The only metallic incoming service is oil from a tank outside.
Can I install a dedicated earth spike for the outhouse and bond the oil to that or do I need to bond it back to the MET in the house?

I'd be grateful for any advice on this.

Ed

 

[vernam616]

Dont see why not, as long as you test the earth rod to ensure it falls within the correct parameters

 

[Deleted member 26818]

You say the only incoming service is metallic, what about the outgoing, are they all plastic?

 

[Von Vardo]

Yes, all pipework throughout the house is plastic, incoming water is plastic but oil is metal.

 

[Deleted member 26818]

Will you isolate the CPC from the house at the boiler?
Will there be any earth paths from the boiler to thermostats?

 

[telectrix]

i would say that if the oil pipe is introducing an earth potential into the house then it needs bonding to the MET.

 

[topquark]

I'm with Tel on this one, bond the incoming pipe to the MET. Assuming that there is no supply from the house to the outbuilding, for example feeding a pump (assuming this is gravity fed to the house).

 

[Von Vardo]

The thermostat is wireless and CPC will be isolated from the house so this should be ok?

 

[Deleted member 26818]

Is there lighting or other power in the out house?

 

[Von Vardo]

Outhouse only contains the boiler and a light (it's more like a shed!) - my thinking is to install a 2 way CU fed by SWA from the house, isolate SWA CPC and install a spike for the bonding and the circuits in the outhouse. Can you see any problem with that?

 

[telectrix]

i'd prefer to export the earth!!! (going to bed now)

 

[Deleted member 26818]

No that would be fine, obviously you will need RCD protection.
If you install a larger CU, then you would allow for the installation of a socket-outlet, either now or at a later date.

 

[Von Vardo]

Great, thanks for your help!

Tel - I was trying not to open that can of worms!

 

[Engineer54]

Why would you TT this outbuilding/shed?? Is it a PME supply to the main house??

Whether it's PME or not, you will still have to bond the service oil pipe as it enters the main house, if it is introducing an earth potential into the house.

 

[Deleted member 26818]

Why would you TT this outbuilding/shed?? Is it a PME supply to the main house??

Whether it's PME or not, you will still have to bond the service oil pipe as it enters the main house, if it is introducing an earth potential into the house.

Because installing a 10mm² bonding conductor from the shed to the house may be more expensive than installing a rod.
Does the oil service pipe enter the house, at the moment it appears to only go to the shed.

 

[Von Vardo]

Oil pipe doesn't enter house - it IRS to the boiler in the shed from which all the pipework to the house is plastic. House is tt.

 

[telectrix]

ah, you've only just mentioned that the pipework from the boiler to the house is plastic! i was thinking it was metal. in that case your original scenario is OK.

 

[malcolmsanford]

Shall we throw in anything about an earth at the filling point at the tank ?

 

[telectrix]

bung in another rod.

 

[Engineer54]

Shall we throw in anything about an earth at the filling point at the tank ?

Yes!! is the simple answer to that question!! ...lol!!!