main bonding to external boilers

[nick611]

Ip 65 rated boiler sat on concrete slab next to building.flow and return pipe leaving boiler,entering building without contact with soil.main bonding or not ?

 

[jam2020]

yeah osg p.27 metal central heating and air conditioning systems require equipotential bonding

 

[nick611]

see that but as its a combi boiler isn,t it already done through the main water bond?

 

[jam2020]

i would do it regardless, that way you cant be wrong.

 

[nick611]

yes best option.but if board on other side of building perhaps a costly one.real question i suppose are the pipes extraneous since not connected to soil,bit puzzling really

 

[jam2020]

dont think connected to soil is anything to do with extraneous. extraneous is something that can introduce earth potential but is not part of the electrical installation.

 

[Deleted member 9648]

yeah osg p.27 metal central heating and air conditioning systems require equipotential bonding

Only if they are extraneous conductive parts.....Generally an AC or CH system is wholly within the equipotential zone and so is not classed as an extraneous conductive part and therefore will not require main bonding.
If the boiler is external,in contact with the ground, with metallic pipework coming into the building it is likely that the pipes will be extraneous conductive and will require main bonding at the point of entry.

 

[jam2020]

i thought thats what we were talking about? ive never fitted an external boiler that doesnt have any extraneous parts/pipework.

 

[nick611]

can,t produce an earth potential if its not connected to the earth[soil] can it whatever it is

 

[Hawk81]

dont think connected to soil is anything to do with extraneous. extraneous is something that can introduce earth potential but is not part of the electrical installation.

and if these pipes are not connected to the soil how would they introduce an earth potential?

 

[nick611]

are you confusing main bonding with supplementry bonding no need to cross bond boiler pipes anymore.are,nt flow and return just boiler pipes?

 

[jam2020]

no supp bonding required if installation meets 7671, personally if there is exposed metal pipe work outside i would bond it and have done with the worry.is it a big hassle to do now?

 

[nick611]

thats my point.if not connected to soil.no potential so not extranous.right or wrong?

 

[nick611]

not allways but sometimes real big problem.cant get a definative answer

 

[jam2020]

are there any manufacturers requirments?