Dog grroming parlour - electric shower et al

[SpannerSpark]

Hi all, a friend is creating a dog grooming parlour in his adjoining garage. He asked for some advice from me regarding the install. I am C&G qualified back in 2008 (installation, test, inspection) but work mainly in electronics, so am rusty.
He has a builder who will run in the cables, i stressed it needs test inspection and someone part p accredited to sign off (I am not due to above). Not sure who he is going to get to do that bit.

The garage needs lights, appliances (a motorised platform, hairdryer, 2kw heater etc.), an electric shower.
I suggested 6A radial in 1.5mm TW/E for lights, 32A ring in 2.5mm TW/E for sockets (or 4mm radial), 40A radial for shower (assume @10kW) in 6mm TW/E (its a short free clipped run). Total load @78A

CU in garage with 80A double width 30mA RCD, 3 x MCBs to suit above circuits.

16mm 3-core SWA from main supply to garage 77A free clipped (the main house design lends itself for the SWA to be free clipped and unobtrusive). The run is 10-15m. PME exported to garage. A switched fuse (80A?) at the origin of the supply.

The main problem is that although the house is only 20-25 years old it only has a 60A main fuse. 25mm from PME head to meter, then 16mm from meter to main CU, another 16mm from meter to off peak CU.
I have advised the DNO needs to asses if the supply an be uprated to 100A, assuming they will uprate tails to 25mm at the same time.

Any suggestions welcome.

 

[Guest55]

fairly straightforward job , just a few minor issues to iron out.

you dont really need a 10kw shower for pets , most are washed with mildly warm water so a 8.5 or even 7.2 kw shower will suffice , which will save on costs and reduce loading.

the supply to the garage will probably only need fusing at 50 -63a , 80a is alot more than you need once diversity is applied.

i'd probably go with rcbos for circuits in the garage CU , will cause less of a nuisance if anything trips out in what is in effect , a commercial / business enviroment

 

[telectrix]

and if the wiring is surface, RCD protection to the lighting is optional.

 

[Guitarist]

He has a builder who will run in the cables.....


Any suggestions welcome.

You really don't want to know my suggestion....

 

[SpannerSpark]

Thanks, doesnt sound like i have sold him a pup. Will take comments on board.
We had discussed lower kW showers but he wanted the option to go up to 10kW if reqd.
I know the sort of suggestion you would make re the builder "doing a bit of electrics" but all i can do is offer best advice, he may not take it regarding getting signed off.

 

[telectrix]

if a builder is running the cables, make sure you do continuity and IR tests before going any further.

 

[Guitarist]

if a builder is running the cables, make sure you do continuity and IR tests before going any further.

Sorry, but if the builder was running the cables, I certainly wouldn't sign it off, and neither should anyone else.

 

[Adam W]

and if the wiring is surface, RCD protection to the lighting is optional.

No RCD protection in a location containing a bath or shower?

 

[Engineer54]

The last thing you would want to use for washing/bathing dogs is an instantaneous electric shower!! It's going to be way too hot for them. Far better off with an immersion heater with provision to mix the hot and cold water... Using the immersion heater set-up you'll be very lucky to see anywhere near 50A at the garage....

A 10 KW shower is just totally ludicrous!!

As for the PME supply he will need to run a 3 core SWA, (or 2 core with a separate 10mm bonding conductor) so as to extend the house equipotential zone bonding requirements... I see that's been covered in your OP.

EDIT.... You then won't need a 100A fuse/tail upgrade either, maybe an upgrade to 80A cut-out fuses, but that's about it. The 16mm tails are fine for 80A.... A far cheaper installation all round, and with a very substantial running costs bonus too... lol!!

 

[telectrix]

No RCD protection in a location containing a bath or shower?

was specified in OP.

 

[Guitarist]

No RCD protection in a location containing a bath or shower?

We've been here before. Would you consider a large sink that a dog gets into "a bath or shower"? My kitchen sink would be classed as a bath if I threw my moggy in it. If tel threw his little thoroughbred into a metal bowl, THAT would be a bath to her.

 

[telectrix]

if i put her in a saucer, it'd be a bath to her.

 

[Octopus]

Hi all, a friend is creating a dog grooming parlour in his adjoining garage. He asked for some advice from me regarding the install. I am C&G qualified back in 2008 (installation, test, inspection) but work mainly in electronics, so am rusty.
He has a builder who will run in the cables, i stressed it needs test inspection and someone part p accredited to sign off (I am not due to above). Not sure who he is going to get to do that bit.

The garage needs lights, appliances (a motorised platform, hairdryer, 2kw heater etc.), an electric shower.
I suggested 6A radial in 1.5mm TW/E for lights, 32A ring in 2.5mm TW/E for sockets (or 4mm radial), 40A radial for shower (assume @10kW) in 6mm TW/E (its a short free clipped run). Total load @78A

CU in garage with 80A double width 30mA RCD, 3 x MCBs to suit above circuits.

16mm 3-core SWA from main supply to garage 77A free clipped (the main house design lends itself for the SWA to be free clipped and unobtrusive). The run is 10-15m. PME exported to garage. A switched fuse (80A?) at the origin of the supply.

The main problem is that although the house is only 20-25 years old it only has a 60A main fuse. 25mm from PME head to meter, then 16mm from meter to main CU, another 16mm from meter to off peak CU.
I have advised the DNO needs to asses if the supply an be uprated to 100A, assuming they will uprate tails to 25mm at the same time.

Any suggestions welcome.

Yup.... tell the builder to concentrate on the bricks and mortar and leave a competent sparky to do the electrics.

 

[Guitarist]

Yup.... tell the builder to concentrate on the bricks and mortar and leave a competent sparky to do the electrics.

But lectrics are easy, innit...

 

[Octopus]

But lectrics are easy, innit...

Especially when the "installer" doesn't understand or follow the regs.

 

[Guitarist]

Especially when the "installer" doesn't understand or follow the regs.

Lost track of the number of times a builder has tried to tell me the regs "coz my electrician don't do it that way"....

 

[Rockingit]

E54 - in my experience, every place we've ever taken our mutt to has used an electric shower unit, and that's loads of places as they forever seem to open under false hope and bad research and close six months later!

If you take guidance from the regs with regards to livestock, then there is very much a case to treat this as no different from any other 701/702 location as animals are more susceptible than we are.

Besides, with RCBO's being so cheap these days its hardly worth the bother of not doing it.

 

[Guitarist]

E54 - in my experience, every place we've ever taken our mutt to has used an electric shower unit, and that's loads of places as they forever seem to open under false hope and bad research and close six months later!

If you take guidance from the regs with regards to livestock, then there is very much a case to treat this as no different from any other 701/702 location as animals are more susceptible than we are.

Besides, with RCBO's being so cheap these days its hardly worth the bother of not doing it.

Agree entirely.

 

[Sharpend]

Yup.... tell the builder to concentrate on the bricks and mortar and leave a competent sparky to do the electrics.

Ain't that the truth!

 

[Marnik]

(The garage needs lights, appliances (a motorised platform, hairdryer, 2kw heater etc.), an electric shower.
I suggested 6A radial in 1.5mm TW/E for lights, 32A ring in 2.5mm TW/E for sockets (or 4mm radial), 40A radial for shower (assume @10kW) in 6mm TW/E (its a short free clipped run). Total load @78A)


With diversity applied, will be more in the region of 47A