Earth bonding for shower pump

[Detritus]

hi,

I've fitted a new shower pump as my old Mira one packed in. I've replaced it with a Stuart Turner Monsoon 3.0 bit have a question about the bonding. The four pipes were bonded together with earthing cable and this was then attached to a small earth screw on the bottom of the old Mira pump. However the new Stuart turner pump doesn't have this? The instruction manual just says that the four pipes should be bonded together and that in some circumstances equipotential bonding may be required - see p.13 section 4.15 to 4.28:
http://www.stuart-turner.co.uk/medi...gle-and-Twin-ShowerPump-WholeHousePump-IG.pdf
I've left the four pipes bonded together but I've removed the earth wire that went to the bottom of the old pump as there is no where to connect it to. Is this OK or should I be connecting it to somewhere else?

Thanks,

Jez

 

[EFLImpudence]

I'm afraid the instructions 4-15,17 & 18 are nonsense.

The pump must be earthed - by the supply cable.

This has nothing to do with whether the pipework might require bonding.


Do you have RCDs in your consumer unit?

 

[JohnW2]

I'm afraid the instructions 4-15,17 & 18 are nonsense.

I definitely agree about 4-15 & 4-17.

As for 4-18, if the "certain installations" it talks about are "certain bathrooms", then I suppose it is right in saying that some (not many!) bathrooms do require supplementary bonding, and that one should refer to the regs to find out if a particular bathroom does.

Kind Regards, John

 

[EFLImpudence]

Fair enough.

I included it because of "additional earthing" in the headline and text.

 

[JohnW2]

Fair enough. I included it because of "additional earthing" in the headline and text.

Yes, that's fair enough, too. However, at risk of re-igniting a 'war', it is 'only' the incorrect terminology which is an issue - what it actually says about "additional earthing arrangements such as equipotential bonding" is true, even if what it is talking about is not correctly termed as an "earthing arrangement".

For the record, amidst its other nonsense, 4-17 also talks of "supplementary earth bonding"

Kind Regards, John

 

[Detritus]

Hi,

Thanks for the replies!

Yes I have RCDs in my consumer unit. The pump is connected via the fitted supply cable which had the standard live, neutral and earth cables - I've put a plug on this and it's connected to a socket in the siring cupboard (this is how the previous one was powered).

So do I need to connect the bonding between the pipes to another earth - or is it OK that they are just connected to each other?

Also - I notice that in the airing cupboard all the other pipes are bonded together but not to the shower pipes - should I do this?

Thanks,

Jez

 

[EFLImpudence]

Yes I have RCDs in my consumer unit.

Then, if all the circuits to the bathroom are covered by RCDs AND the main bonding (to metal pipes entering the building) is satisfactory AND all the circuits' disconnection times (i.e. MCBs work properly) are satisfactory then supplementary bonding in the bathroom may be omitted.

The pump is connected via the fitted supply cable which had the standard live, neutral and earth cables - I've put a plug on this and it's connected to a socket in the siring cupboard (this is how the previous one was powered).

That's fine.

So do I need to connect the bonding between the pipes to another earth

No.

or is it OK that they are just connected to each other?

Yes. If the above conditions are met none of it is needed.
The two pipes from pump to shower probably should not have been bonded at all but if you cannot touch them when in the bathroom it shouldn't be a problem.

Also - I notice that in the airing cupboard all the other pipes are bonded together but not to the shower pipes - should I do this?

No - not necessary.

 

[Detritus]

Thanks very much for the replies, really appreciated!its really great that knowledgable people such as yourselves are willing to help those of us who are starting out.

Jez

 

[Detritus]

Actually just to be sure - can someone verify from the image that these are RCDs and not just mcbs please?

ConsumerUnit

• Detritus
• 18 Sep 2017

 

[ban-all-sheds]

Yup - the two devices with test buttons are RCDs.

 

[JohnW2]

Actually just to be sure - can someone verify from the image that these are RCDs and not just mcbs please?

As you have been told, your photo confirms that all your circuits (including those serving your bathroom) are protected by RCDs.

However, don't forget that, as EFLI explained to you, there are two other conditions (in addition to RCD protection) which need to be satisfied in order for it to be permissible for supplementary bonding to be omitted. It is very likely that those other conditions would be satisfied in your electrical installation, but you would really need an electrician to confirm that.

Kind Regards, John

 

[Detritus]

Thanks all. What would supplementary bonding entail? This is all new to me as I'm sure you can tell! Is there an online resource you can point me at that a layman like me would be able to understand?

Thanks,

Jez

 

[Taylortwocities]

Info in the WIKI at
https://www.diynot.com/wiki/Electrics:Supbond17th
should help..

 

[Detritus]

Thanks again!

 

[flameport]

ConsumerUnit

• Detritus
• 18 Sep 2017

A severe lack of labelling there - none of the circuits are identified and whoever slapped the other labels on couldn't even be bothered to complete the dates on the test label.