RCD Protection for Shower Pumps?

[autolycus]

Hi,

The house we moved into about a month ago has two shower pumps in the loft – a 2 bar one for the ensuite and a 1.5 bar one for the main bathroom. They get their electrical supply via a standard double 13amp socket in the loft.

I had assumed that this 13amp double socket was spurred off the upstairs ring main and hence protected by both an MCB and the RCD that are part of the main consumer unit.

However, I wasn’t 100% sure of this, partly because our house has two separate consumer units. Yesterday, I decided to check out exactly how the whole place was wired up in terms of these two consumer units.

Here’s what we’ve got. We have a modern consumer unit in the garage which has 10 MCBs, all protected by an RCD. One of the 10 circuits on this consumer unit is the upstairs ring main. It also has circuits for the lights in all of the house except one room, the cooker, the central heating, and about half of the downstairs sockets.

Next to that is an old grey isolator switch box with a single 60A cartridge fuse. This stays live regardless of the state of the master switch on the aforementioned consumer unit.

What this isolator does is supply a feed to a second consumer unit in the utility room. This second unit is one of the old style ones with cartridge fuses. It supplies the lights in the utility room, and the remaining downstairs sockets (the ones that aren’t fed via the consumer unit in the garage).

It turns out that the socket in the loft for the shower pumps is not on the upstairs ring circuit that is supplied from the modern consumer unit after all. Instead, it is on the same circuit as the immersion heater, which is a 15A (cartridge) fused circuit on the old style consumer unit in the utility room. So, in a nutshell, the shower pump supply has no MCB and no RCD.

All of the (visible) pipework for the showers is earth bonded as far as I can see.

Questions then are as follows:

1. Is it advisable and/or a requirement for the shower pump to be protected by an MCB and/or an RCD?
2. if an MCB is required, can I use some kind of simple plug in replacement for the existing cartridge fuse
3. If an RCD is required, is it acceptable simply to replace the existing 13amp outlet in the loft with one of these instead: http://www.screwfix.com/prods/57865/Electrical/RCDs/Volex-2G-DP-RCD-Skt

Is there anything else about what I have described above that rings alarm bells?

Thanks in advance,
Dave.

 

[Adam_151]

If I was fitting them, then I'd put them on RCD, but if they are outside of the bathroom, then I wouldn't consider it as important to put it on RCD as I would an electric shower which is actually inside the shower cubicle, and certainly (unless the maker of the pumps says otherwise) no current requirement to RCD them.



That said, its considered bad practice to tap things onto the water heater circuit, and it sounds like you need a bit of TLC on your electrics, downstairs sockets generally need RCD protection, etc, not sure why one board was changed and not the other. Have you got a certficate for the board change? and has he left quite a few ways spare in the new one?

 

[autolycus]

If I was fitting them, then I'd put them on RCD, but if they are outside of the bathroom, then I wouldn't consider it as important to put it on RCD as I would an electric shower which is actually inside the shower cubicle, and certainly (unless the maker of the pumps says otherwise) no current requirement to RCD them.

Fair enough. If I do decide to go ahead and RCD them, is the suggested faceplate replacement an acceptable way to do it - i.e. just as good as having an RCD on the consumer unit?

That said, its considered bad practice to tap things onto the water heater circuit

No doubt it was done like that because the airing cupboard was the easiest place from which to run a spur into the loft without having unsightly wiring on show.

and it sounds like you need a bit of TLC on your electrics, downstairs sockets generally need RCD protection

Most of them have got RCD protection - i.e. those which are fed from the main consumer unit

not sure why one board was changed and not the other. Have you got a certficate for the board change? and has he left quite a few ways spare in the new one?

No certificate.

The modern board has no spare ways on it (although there is one 5A circuit which seems do nothing other than power a single 60W outside lantern, so perhaps whoever installed it didn't like to leave anything unused [wink]).

The old style one in the utility room only has five circuits:
5A - utility room light and a couple of outside lights
30A - spur to outbuilding (which has its own consumer unit)
30A - downstairs sockets for the parts of the house (including the utility room itself) that were added (in phases) as an extension
15A - immersion heater and this socket in the loft
5A - not sure what this is used for; I can see wiring going to the fuse but pulling the fuse doesn't seem to stop anything working.

 

[Adam_151]

I'd generally prefer to see shower pumps connected by FCU rather than plugged in, but I suppose as long as the pumps are near the outlet and you haven't got flexes trailing everywhere, then its non too bad.

I don't think I'd worry about RCD'ing the shower pumps too much tbh, but that said, someone here said about it being a good idea to have RCD protection on loft outlets due to a handlamp being dropped in a water storage tank scenero, and next year, RCD protetcion for all outlets that could be used for generic applicances will most likely be a requirement of BS7671, its not yet, though

Volex is not considered a very good make, certainly the last volex accessary I tried to use, the screws sheared off on!


Back to RCDs for socket outlets, does the consumer unit in the outbuilding have an RCD as the incommer, the requirement at present is for socket outlets that could reasonably be expected to supply portable equipment outdoors to be RCD protected (the favourite interpretation is that means all ground floor ones, but thats not always cast in stone, the designer can use his judgement!), next year we won't worry about it, because all general purpose socket outlets of 20A or less will be required to be RCD'd anyway! (well thats what we keep being told, BS7671:2008 hasn't actually been printed yet)

As for that 5A fuse, pull it out and leave it out until you find something that doesn't work... but check your fire alarms, intruder alarm and doorbells still work!

 

[autolycus]

Back to RCDs for socket outlets, does the consumer unit in the outbuilding have an RCD as the incommer,

Yes - it is a Wylex unit with an RCD main switch and then MCBs for each of the four circuits.

Just come across another issue whilst digging around by the consumer unit. Probably best start a separate thread for that though......

 

[Pensdown]

Fair enough. If I do decide to go ahead and RCD them, is the suggested faceplate replacement an acceptable way to do it - i.e. just as good as having an RCD on the consumer unit?

Socket outlets with integral RCDs are just as good as the ones in consumer units.

In fact in your case I would say they were a better option because if you do get an earth fault on your shower pump it will not trip anything else.

 

[Adam_151]

Yeah, what pen said (just don't by volex )