Can this CU manage an electric shower?

[Jonmyates]

All,

Thank you for your help and suggestions, much appreciated!

Now I have a couple of options and know who I need to get in.

Regards,

Jon

 

[ban-all-sheds]

It's not totally clear, but does that label not say that the IΔn of the RCD is "0.3A" (aka 300mA)?

Yes.

GF 280300.

I wonder.

GF, 2, 80, 300

Ground Fault, Number of poles, In, IΔn ?

 

[ericmark]

I have both electric instant and a plumbed hot and cold shower and the plumbed one is so much better. What can cause a problem is height of the cold water tank, if in the airing cupboard it is often too low to power a shower without a pump, which is called a power shower, if in the loft then should be OK without a pump, so it would seem two options open to you.

1) One run a cold water pipe from header tank to shower and fit a plumbed shower.
2) Do a rewire, fit a new consumer unit with a 30 mA RCD and have an electric shower.

The cost for electric would be prohibitive likely around the £500 to £2000 for electric depending what is found to be required, and £200 for plumbed option which is better anyway. So if it were me I would forget about the electric shower.

 

[JohnW2]

I have both electric instant and a plumbed hot and cold shower and the plumbed one is so much better. What can cause a problem is height of the cold water tank ... so it would seem two options open to you.

As three of us have said, probably the most likely cause of what the OP describes is that the cold water ius coming from the 'mains', not form the storage tank. If that is the case then rectifying that situation would be a third, and possibly adequate, option.

Kind Regards, John

 

[Risteard]

As above, you'd need to check how much your max current can be.
Your service fuse could well be only 60amp, so plonking a 40A shower on there is going to stop you using much else at the same time.
If it is big enough, then you'd need a separate mini consumer unit to supply the shower itself, or a complete new consumer unit.

This would need doing by a registered electrician and I recommend you have one come and tell you what your options and the costs might be.
Have him use an RCD tester to check that the old Ottermill box is still up to scratch. It is the safety barrier for you and your family.

It's not up to scratch - a 300mA RCD won't provide 30mA protection.

 

[JohnW2]

It's not up to scratch - a 300mA RCD won't provide 30mA protection.

Indeed, I've already made essentially the same observation - i.e. that, even if it is 'up to scratch' (in terms of what it says on the tin), a 300mA will not provide any useful protection in the event of an electric shock (although it obviously may clear a fault before anyone has a chance to get a shock).

In any event, as has been said, the OP may well not need an electric shower if (as several of us think may be the underlying problem) he gets his plumbing sorted out.

Kind Regards, John

 

[EFLImpudence]

TTC did say a new shower CU would be required.

 

[JohnW2]

TTC did say a new shower CU would be required.

He did, but he also said ...

Have him use an RCD tester to check that the old Ottermill box is still up to scratch. It is the safety barrier for you and your family.

Was he perhaps assuming that it was a TT installation and that the 300mA RCD needed to be 'up to scratch' to provide ADS ("the safety barrier for you and your family"), rather than 'personal protection' (the latter being what I thought he meant)?

Kind Regards, John

 

[EFLImpudence]

I presume he just meant to show it still works and if not, replace it.

 

[ban-all-sheds]

So you'd agree with leaving a 300mA RCD in service?

 

[EFLImpudence]

I was merely trying to translate

"Have him use an RCD tester to check that the old Ottermill box is still up to scratch"

for John who, strangely, can decipher meanings from near gibberish but not clear writing.



Are you stating the householder shall be forced to replace it?

 

[ban-all-sheds]

OK.

But I admit I struggle to see why, as it cannot be "up to scratch".

Replacing it is not mandatory, but it is such a BGI why spend a penny investigating whether the old one will not or will not provide useful safety?

 

[SimonH2]

... if in the loft then should be OK without a pump ...

Many will claim that you can't have a usable gravity shower with that little head - in practice, it's going to be around 6 feet of head. While it will never be "invigorating", you can get a perfectly usable shower (I used one for many years) - with the right parts.
You need a good valve (we had a standard Mira valve), large bore flexible hose, and a low pressure head.

 

[JohnW2]

I was merely trying to translate "Have him use an RCD tester to check that the old Ottermill box is still up to scratch" for John who, strangely, can decipher meanings from near gibberish but not clear writing.

I presume he just meant to show it still works and if not, replace it.

He probably did (albeit 300mA seems unnecessarily high, even if it is for ADS in a TT installation) but it was his following sentence which led to the comment I made ...

... It is the safety barrier for you and your family.

Maybe I'm wrong (again), but I took that as a reference to 'personal protection' (for which a 300mA, or even a 100mA, RCD would obviously be pretty useless), not to ADS. Do you disagree?

Kind Regards, John

 

[EFLImpudence]

Perhaps TTC should have said 'A safety barrier'.

It's there; that's all there is; may as well see if it still works.