Power shower wiring
Rhys Dexter
the experts out there.
After successfuly wiring up my kitchen which has worked for many moons
with no probs, I thought I'd have a stab at a power shower. All the
plumbing is sorted but I'm having a bit of difficulty with the wiring
of it.
The shower is one of the Mira Event Thermostatic showers and this
requires a dedicated 30A feed from the CU. No probs there. Quick trip
to B&Q sorts me out with a 32A MCB (don't seem to do a 30A one).
Problem comes when it says that sitting in between the CU and shower
needs to be a 3A double pole switch.
I have had a hunt around B&Q and the like and cannot find a 3A
version, I think I only came across a 20A. Now as these things cannot
swop fuses, I cannot obviously use this as 20A going into my shower
would not be a good move at all.
So I was wondering if I can use a fused connection unit which has
removable fuses, and simply toss a 3A fuse into there.
Any help would be very much appreciated.
OT very briefly, my company fuse for the house is only 60A. Now with a
power shower, electric oven and God knows what else running I don't
think 60A will cut it anymore. Can you buy 100A fuses and just replace
it (I know....not recommended, but the leccy company turns a blind
eye) or do I have to get some bods out from somewhere.
Regards,
Mark
John Laird
>Problem comes when it says that sitting in between the CU and shower
>needs to be a 3A double pole switch.
Substitute 30A for 3A and I think all will become clearer. The switch is
required to isolate the appliance which would otherwise be directly
connected to the MCU. Oh, and the rating value does not imply a fuse -
these are pure switches. If the switch is to be inside the shower room, it
will have to be a ceiling-mounted pull-cord. You may find it easier to find
45A switches and there will be no harm in using one.
I see regulations now say an RCD must also be installed, either on that part
of the MCU providing the shower circuit, or on the shower circuit itself.
John
Jack Ross
<jo...@laird-towers.org.uk> wrote:
>On 18 Apr 2003 04:33:21 -0700, blade...@hotmail.com (Rhys Dexter) wrote:
>
>>Problem comes when it says that sitting in between the CU and shower
>>needs to be a 3A double pole switch.
>
>Substitute 30A for 3A and I think all will become clearer. The switch is
>required to isolate the appliance which would otherwise be directly
>connected to the MCU. Oh, and the rating value does not imply a fuse -
>these are pure switches. If the switch is to be inside the shower room, it
>will have to be a ceiling-mounted pull-cord. You may find it easier to find
>45A switches and there will be no harm in using one.
>
Thanks John. I did wonder. Otherwise what would be the point of a 32A
connection if only 3A was getting to the shower. What do they mean
then when they say :
"Appliance power supply 230-240V, 50hz, fused at 3 Amps via a double
pole switched fused connection unit(not supplied)"
Sorry if this sounds a bit rudimentary and stoopid but it kind of
threw me a bit as I was all set to use a pull cord (I believe I saw a
45A one in Homebase) when they laid this 3 Amp thing on me.
>I see regulations now say an RCD must also be installed, either on that part
>of the MCU providing the shower circuit, or on the shower circuit itself.
>
Yes indeedy....I did note this point in the manual and it is certainly
something I will procure before using the shower.
Thank you for your help.
Mark
BillP
"Rhys Dexter" <blade...@hotmail.com> wrote in message
news:f976d14.03041...@posting.google.com...
Mark,
Are we sure what we have here? The mira event is indeed a power shower. It
does not heat the water, it is fed with low pressure hot and cold water and
has an integral pump to boost the flow. This will be connected via 3 amp FCU
or and RCD FCU fused at 3 amps.
Check your installation manual, does the plumbing instructions call for
connections to hot and cold supplies?
Bill
Owain
| >>Problem comes when it says that sitting in between the CU and shower
| >>needs to be a 3A double pole switch.
| >Substitute 30A for 3A and I think all will become clearer.
| connection if only 3A was getting to the shower. What do they mean
| then when they say :
| "Appliance power supply 230-240V, 50hz, fused at 3 Amps via a double
| pole switched fused connection unit(not supplied)"
Is this a shower pump or an instantaneous electric shower? Is there a kW
rating anywhere?
Because if it's an instananeous electric shower (which would be 6-10 kW) it
needs 30A or 45A dedicated shower circuit and if it's a shower pump, which
would be a few hundred W it can be 3A and, unless someone knows different,
spurred off a power ring.
It sounds as though some gibbon has mail-merged the instructions for
completely different appliances into one document.
Owain
Jack Ross
>
>Are we sure what we have here? The mira event is indeed a power shower. It
>does not heat the water, it is fed with low pressure hot and cold water and
>has an integral pump to boost the flow. This will be connected via 3 amp FCU
>or and RCD FCU fused at 3 amps.
>
>Check your installation manual, does the plumbing instructions call for
>connections to hot and cold supplies?
>
>Bill
>
Hi Bill,
What you say is perfectly correct. The internal pump uses seperate hot
and cold water plumbed in which I have done so no problems there.
The instruction manual mentions needing a 30mA RCD fitted which is
fair enough. My CU doesn't have an RCD currently, so I guess I better
fit one anyway.
It then asks for this double pole switched 3amp FCU.
I've just read the manual again and it doesn't actually mention
needing a dedicated power supply which I presumed (I
know...presumption etc etc) all electric/power showers needed.
By specifying the requirement for a 3A FCU this must surely mean that
I wouldn't necessarily need a 30A dedicated power supply.
I'm somewhat confused to be honest.
http://www.mirashowers.com/onlinecatalog/pdf/p3821_1.pdf
This is the link to the installation instructions.
I would appreciate any help you could shed upon this.
Best regards,
Mark
Jack Ross
<owai...@stirlingcity.co.uk> wrote:
>Because if it's an instananeous electric shower (which would be 6-10 kW) it
>needs 30A or 45A dedicated shower circuit and if it's a shower pump, which
>would be a few hundred W it can be 3A and, unless someone knows different,
>spurred off a power ring.
>
>It sounds as though some gibbon has mail-merged the instructions for
>completely different appliances into one document.
>
>Owain
>
>
Hi Owain,
Yes it would seem so wouldn't it.
The shower has an in-built pump which takes a seperate hot and cold
feed.
Upon looking at the instructions, I can confirm that the absorbed
power of the shower is 150watts under normal working conditions (what
would un-normal conditions be for a shower??)
Thanks,
Mark
BillP
"Jack Ross" <blade1971...@hotmail.com> wrote in message
news:q5a0av829pj6fesdd...@4ax.com...
High Mark,
You can spur off the ring main or, as the pump motor is only rated at about
150 watts you can connect off a suitable point from the lighting supply. If
you fit an RCD fused connection unit like screwfix part number D14770 and
fit it with a 3 amp fuse that works as your RCD and switch.
Bill.
Jack Ross
Hi Bill,
Thanks very much for your help. It seems so obvious now.
I suppose it was a fair chunk of naivety(sp?) on my part as I just
"assumed" after searching other messages and looking on the web, that
all elec/power showers required a nice fat 30A+ dedicated supply.
I just happen to have a nice lighting circuit that runs across my
bathroom ceiling. Best to do that, or the sockets ring main? Don't
suppose it matters for a piddling 150W.
Thanks again,
Mark
BillP
>
> You can spur off the ring main or, as the pump motor is only rated at
about
> 150 watts you can connect off a suitable point from the lighting supply.
If
> you fit an RCD fused connection unit like screwfix part number D14770 and
> fit it with a 3 amp fuse that works as your RCD and switch.
>
> Bill.
>
>
Sorry Mark,
Just looked in the Screwfix book, the D14770 does not satisfy the
requirement for the doulble pole switch, as it does not disconnect the
neutral. You could fit the D14770, as your RCD, fit it with a 5 amp fuse,
then fit a doulble pole switch, or fit a standard double pole FCU and fit a
3 amp fuse to that.
Bill
Dave Liquorice
> "Appliance power supply 230-240V, 50hz, fused at 3 Amps via a double
> pole switched fused connection unit(not supplied)"
One assumes that this shower is *not* heating any water at all. It
takes hot and cold water from the normal supplies. It just needs a
little bit of power to run the pump.
3A is about 750W, it might be able raise the temp of your cold water
by a degree or two at most.
--
Cheers new...@howhill.com
Dave. Remove "spam" for valid email.
Jack Ross
Hi Bill,
Just took a look at their website and apparently it does disconnect
neutral leaving just earth connected.
So I take it once I confirm whether the catalogue or website is lying,
then I could use it or take up one of your other suggestions.
Thank you,
Mark
Owain
| "BillP" wrote:
| >Are we sure what we have here? The mira event is indeed a power shower.
It
| >does not heat the water, it is fed with low pressure hot and cold water
and
| >has an integral pump to boost the flow. This will be connected via 3 amp
FCU
| >or and RCD FCU fused at 3 amps.
| fair enough. My CU doesn't have an RCD currently, so I guess I better
| It then asks for this double pole switched 3amp FCU.
That's fine. And you can get an FCU with integral RCD, which would enable
you to spur off a convenient socket on a power ring (mount the FCU/RCD
outside the bathroom) without faffing about at the consumer unit.
http://www.tlc-direct.co.uk/Products/CM4904.html
http://www.tlc-direct.co.uk/Products/BRH92.html
Both are double pole switched, (but I do not know if they comply with 3mm
contact gap.)
| By specifying the requirement for a 3A FCU this must surely mean that
| I wouldn't necessarily need a 30A dedicated power supply.
Yes.
Before connecting to a lighting circuit, check how many lights are already
on it. Each lighting point is rated at 100 W or actual load if higher, and a
5/6A lighting circuit = about 1200 W, so only connect it to a lighting cct
if you have fewer than about 10 lights already on it.
Owain
BillP
> Hi Bill,
>
> Just took a look at their website and apparently it does disconnect
> neutral leaving just earth connected.
>
> So I take it once I confirm whether the catalogue or website is lying,
> then I could use it or take up one of your other suggestions.
>
> Thank you,
>
> Mark
>
Yeah you're right Mark, I misread it. I've fitted power showers before and
used these units to combine the RCD and switch function.
Bill.
Jack Ross
Thanks for the help Bill - I'll get cracking on this in the morning.
Regards,
Mark
Jack Ross
Hi Owain,
A lighting circuit would be ideal because I can drop a cable through
from the ceiling in the bathroom.
It's certainly the neater option - don't fancy running cable through
the upstairs to the nearest power point. Would you believe the nearest
one is nearly 10 feet away.
Thanks for the help.
Mark
Jack Ross
I wired up my power shower today after your help and all went well.
Works a dream.
My thanks to you both again for your assistance.
Regards,
Mark