No Equipotential Bonding to Water

[charlie76]

Been to a job today to replace a faulty immersion thermostat. The existing spur supplying it was broken and about 30 years old so I replaced that and installed a DP water heater switch. Also the HR flex to the immersion was cracking through age / heat fatigue so replaced that.

Seems the supply to the existing spur is from the socket ring circuit, not a dedicated circuit. Also appears there is no EP bond on the main incoming water supply to the property. Both items I have notified the client and also written on my Mod cert under 'Comments on existing installation'.

So then I read reg 132.16 to see if I should have actually carried out the above works given the wording there. So the first point in that reg 'ascertain that the rating and condition of existent equipment [is adequate]'. Ok so the cable rating is, I have fused down to 13A at the spur the ring is protected by a B32 MCB, although the immersion soured off the ring arrangement is incorrect I believe it is adequately rated, am I correct in making this statement.

Second point in the regulation 'Earthing and bonding arrangements [etc etc etc]'. The protective measure I have applied to the modification is a 13A BS1363, the circuit Zs is 0.21ohm so all good there. The circuit is also protected for additional protection with a 30mA RCD, so although the main incoming water is not bonded and should be, does this impact on the modification I have carried out. Note, Supplementary bonding is provided in the location of the tank to all pipework of the installation and is also bonded to the main incoming water supply.

The client does intend on me bonding the water supply for them and also installing a separate feed to the immersion. But lets say they decided not to, how does this leave me even though noted on my cert?

 

[westward10]

I wouldn't lose too much sleep over the immersion heater connected from a ring final circuit. Appendix 5 which references this is informative and I would just consider it to be poor installation methods. Ring final circuits are designed to cope with uncoordinated/random 3kw loads so even though it may seem wrong in some eyes it isn't much different to a kettle load and often these circuits are bedroom area circuits which tend to be under minimum loading. The main protective bond to the water service is a higher priority.

 

[Wilko]

Hi Guys,
If I understand correctly, today you were doing a repair (not a modification) so it doesn't require a cert yet? Cheers.

 

[charlie76]

Hi Guys,
If I understand correctly, today you were doing a repair (not a modification) so it doesn't require a cert yet? Cheers.

Oh thats ok then, I'll just walk off and ignore the issue.

What does your statement mean, if it doesn't require a certificate then don't need to worry about the safety?

In my eyes it is minor works in any case. For a start I have added a new DP isolation switch didnt previously exist, replaced the circuit cable from the spur, installed a new spur, new time clock. Come on.

Plus the rest of the place is an electrical mess so I'd rather issue a cert to limit my liability to the works I have done rather than be the last spark in the building with no record of what I did and potentially open me up to some other mess in there.

 

[westward10]

Agreed definitely Minor Works.

 

[Wilko]

Hi Charlie, sorry, I didn't mean to offend with my ill informed question. I didn't read your post closely enough. I see it now. Thanks.

 

[HandySparks]

... Also appears there is no EP bond on the main incoming water supply to the property.

I take it that it's an older property with the incoming water pipe in metal not plastic?

 

[westward10]

I sense a can of worms being opened. If the service pipe is plastic then any copper connected from is not in contact with true earth and as such is not an extraneous conductive part, it seems to be common practice however to bond it.

 

[ruston]

Some older properties can have the heating pipes (uninsulated) or internal supply pipes , even pipes running to an outside tap laying on top of the soil ,or concrete in water underneath the floorboards.
It is fairly common here

 

[HandySparks]

Some older properties can have the heating pipes (uninsulated) or internal supply pipes , even pipes running to an outside tap laying on top of the soil ,or concrete in water underneath the floorboards.
It is fairly common here

True. In which case, maybe they need bonding where each pipe emerges out of the floor?

In fact, I've done exactly that. Supply to the house was in poly, but then it ran about on the concrete base below the floorboards. So I put in a MEB, even though it probably wasn't extraneous at the time, the space under the floor being bone dry at the time. A lot of this stuff isn't clear cut, but down to individual judgement.