Oil service bond metal tank pme

[suffolkspark]

I have just done an EICR... Havnt finilised coding yet.

Property is TN-C-S
Incoming oil to boiler... Copper oil line with pvc sheath, buried to metal oil tank sat on slabs on ground (it is not raised up) technical said it should be bonded.... Imo by bonding im taking pme potential out to the lump of metal sat on the slabs & I dont see how this is different to taking pme to metal shipping containers which we dont do for obvious reasons...

Opinions?

 

[Wilko]

Hi - my take is it's an extraneous conductive part so Reg 411.3.1.2 applies and it should be bonded.

 

[Pete999]

I have just done an EICR... Havnt finilised coding yet.

Property is TN-C-S
Incoming oil to boiler... Copper oil line with pvc sheath, buried to metal oil tank sat on slabs on ground (it is not raised up) technical said it should be bonded.... Imo by bonding im taking pme potential out to the lump of metal sat on the slabs & I dont see how this is different to taking pme to metal shipping containers which we dont do for obvious reasons...

Opinions?

Have you tested the tank to see if it rates as an extraneous metal part?

 

[telectrix]

cobblers.can occupants be in simultaneous contact with an earthed part of the electrical installation and the tank?extra long arms? the onlythingthat you can consider extraneous is the fuel pipe.this should be tested to see if it is extraneous before considering bonding the pipe.the tank itself does not require bonding.

 

[suffolkspark]

Thats not what im getting at tel, of course the tank itself wouldn't require bonding, but if the oil line was bonded.... So would be the tank....

Ps tank is about 30m away from house between some outbuildings

Pps yes the oil line did test <22kohm to met with boiler cpc dissconnected

 

[Richard Burns]

It is a level of risk assessment.
If the oil pipe is not bonded it introduces earth potential into the property and on every earth fault that occurs will cause a danger in the property. On loss of supply neutral the metalwork in the property may rise to dangerous potentials, depending on the resistance of any paths to earth.

If the oil pipe is bonded then inside the property is safe during an earth fault but does mean the tank could show a potential difference during the fault. On loss of supply neutral the tank may rise in potential and some supply current may flow to earth via the pipe and tank, this introduces risk near the tank but lowers the potential difference inside the property.

The likelihood of earth faults and someone being near the metalwork in the property during an earth fault is much higher than being near the tank and also in the low risk case of a loss of supply neutral the property is safer where people may be expected to be present.

Overall it should be safer to bond the oil pipe than not bond the oil pipe.