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.

 

[ruston]

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.

That is it. We have a lot of trouble with mine water rising to the surface in a lot of the old pit rows , even some of the newer houses on concrete can have 4" of water under them.
We have lots of little lakes in the fields that grow in the winter lol.
Natural bird sanctuaries is the good side.

 

[sparksburnout]

How do you mean exactly, "But lets say they decided not to, how does this leave me even though noted on my cert?" What are you envisaging might happen?

 

[charlie76]

How do you mean exactly, "But lets say they decided not to, how does this leave me even though noted on my cert?" What are you envisaging might happen?

Well it is unsafe but specifically because the regs under 132.16 say "No addition, alteration, temporary or permanent shall be made to an existing installation unless it has been ascertained that .........etc etc... the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate"

The bonding arrangements are not adequate for the protective measure applied (ADS) and I have carried out alteration...

 

[Octopus]

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?

I would say you have CYA and its NOT your problem .....

You can't make anybody agree to spending more money on a maintenance issue than is required by the nature of the fault.... if you try, you will start pxssing off your clients... so just remember to invoice, note on cert and walk away...

just saying.

 

[westward10]

Think you are over worrying this, the immersion should ideally be on a dedicated circuit but I wouldn't even comment on it. Note the bonding issue on the cert and as Murdoch says, walk away.

 

[sparksburnout]

Well it is unsafe but specifically because the regs under 132.16 say "No addition, alteration, temporary or permanent shall be made to an existing installation unless it has been ascertained that .........etc etc... the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate"

The bonding arrangements are not adequate for the protective measure applied (ADS) and I have carried out alteration...

I agree with Murdoch's line of thinking. You have done the work now, so it's all a bit irrelevant now anyway! You can't be responsible for everything, just note on the cert and crack on. what I meant was, what are you worrying about what might happen when you say you were the last spark there? At the end of the day all you have done is make it safer.

 

[charlie76]

Ok thanks for the advice everyone

 

[Last plumber]

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?

Excuse me for poking my nose in and definitely no offence meant .....but ! I need this answering.
The amount of immersions I have come accross where the fuse has melted the switch fused spur, I've lost count Of.

If voltage is running low ( 230 ). You're immersion's 13A fuse in the switched fused spur, is going to be hot. It will not blow as you know but it can do damage.

I personally ( Heating Engineer, not Electrician), would not be able to bring myself to leave it. It would be a case of telling customer, it needs re-wiring correctly on its own independent supply, 16A breaker and RCD ( or RCBO ) and a 20 A DP switch for customer plus 20 A DP Switch next to immersion.

What are your thoughts ?
Is this over kill ?

 

[Last plumber]

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?

Excuse me for poking my nose in and definitely no offence meant .....but ! I need this answering.
The amount of immersions I have come accross where the fuse has melted the switch fused spur, I've lost count Of.

If voltage is running low ( 230 ). You're immersion's 13A fuse in the switched fused spur, is going to be hot. It will not blow as you know but it can do damage.

I personally ( Heating Engineer, not Electrician), would not be able to bring myself to leave it. It would be a case of telling customer, it needs re-wiring correctly on its own independent supply, 16A breaker and RCD ( or RCBO ) and a 20 A DP switch for customer plus 20 A DP Switch next to immersion.

What are your thoughts ?
Is this over kill ?

 

[David M]

Depends on the size of the immersion element (i.e the wattage)