9600 WATT shower - I want to have 2 fitted & advice need

[wilburwilbur]

Hi all. I'm looking at having TWO Electric showers fitted at my property. I've seen what i would like and they are 9600 WATT at 230 V. I have a modern 17th edition split Consumer Unit installed already, with space for a couple of MCB's on each side. My supply Fuse is 100 AMP, my Consumer unit has a 100A rated Main DP switch, my supply cable is 25mm SQ. I have this info from my install certificate.

I have a single lighting circuit, two ring mains and an immersion heater (but this is a small type tank - i would have to look in the loft to see what the Power rating is). I want two showers as teenagers will use one all the time and i need another free for myself when i want to use it and not wait for them to get out.

I Will be getting a PART P electrician to undertake the works - I just want some advice on what i may be looking at Technically ( doable with what i have installed already ) & money wise.

Thanks in advance.

 

[ricicle]

The first question I would ask is can your water supply sustain two mains fed showers otherwise your washing experience will be hampered !

 

[wilburwilbur]

Yes - Plumbing was upgraded before i moved in the property, plumbing is not a problem at my property.

 

[ricicle]

Ok. How do you cook, particularly the hob - is it electric ? Is the immersion heater the main source of water heating ? Do you have a dishwasher ? How is your house heated ?
Can you see where I am going with this ?

 

[Chri5]

Having 2 x showers on works about 83 amps, that's a load and a half and gives you little overhead should a kettle, a grill or any other heavy juice eating appliance is used at the same time.

What hw do you use, stored via tank heated via boiler? Might be best to think about having one of the showers use that and maybe a pump to add pressure.

 

[Taylortwocities]

Put a pump on the existing hot water (gravity) feeds and give the kids a mixer shower off that. They'll soon learn that there is a limited supply of hot water!

Then, just indulge yourself with an instant heat electric shower.

It's a win-win solution!

 

[JohnW2]

I'm a little surprised that no-one yet seems to have made the usual point that the supply T&Cs would require one to get the DNO's approval/permission before installing two 9.6kW showers.

Does anyone know how they would be likely to react to such a request? As has already been pointed out, both showers working simultaneously together with 'any other significant loads' could be pushing a "100A" supply. We know that it wouldn't blow the cutout fuse (unless the 'other load' was very large and sustained), but that's not really the point.

Kind Regards, John

 

[Taylortwocities]

Aye, trying to get all the parameters first.

Others have asked what the other significant loads are, maybe everything else is gas.

Otherwise you are right.

Two showers going + Christmas Turkey in the oven + boil the kettle

= a Christmas Day call out to the DNO to replace the supply fuse.

Well, they may get there by 28th December..

 

[JohnW2]

Aye, trying to get all the parameters first. Others have asked what the other significant loads are, maybe everything else is gas. Otherwise you are right.

I would strongly suspect that westie, and the DNO's T&Cs, would say that anyone proposing to install 2 x 9.6kW new 'fixed' loads must contact the DNO, regardless of one's personal assessment of the adequacy of the supply to support the maximum demand.

Kind Regards, John

 

[EFLImpudence]

Two showers going + Christmas Turkey in the oven + boil the kettle

Why would anyone need a shower on Christmas day?

I'm a little surprised that no-one yet seems to have made the usual point that the supply T&Cs would require one to get the DNO's approval/permission before installing two 9.6kW showers.

There is no need it will be in the instructions.

 

[JohnW2]

I'm a little surprised that no-one yet seems to have made the usual point that the supply T&Cs would require one to get the DNO's approval/permission before installing two 9.6kW showers.

There is no need it will be in the instructions.

Nothing's impossible

Any idea of the answer to my question - as to how a DNO are likely to react to a proposal to add such a new large 'fixed' load?

Kind Regards, John

 

[EFLImpudence]

Not really. One for the DNO.

If it IS a 100A supply (and not just the rating on the cut-out) it would be difficult to think of a reason why the showers should be forbidden.
Obviously two forty-two amp showers plus a normal domestic demand on a 60A fuse is not advisable.

As I have stated before I find the DNO reasoning illogical if fitting 100A supplies but refusing actual 100A demands.

 

[westie101]

I would strongly suspect that westie, and the DNO's T&Cs, would say that anyone proposing to install 2 x 9.6kW new 'fixed' loads must contact the DNO, regardless of one's personal assessment of the adequacy of the supply to support the maximum demand.

Without looking closely at the network, cable sizes and such it would be hard to decide if permission could be given.
Certainly in the past I have where B&Bs wanted a couple of showers for en-suite rooms. (though we did find one where the 60A cut-out fuse had blown that had two showers and admitted never getting permission to connect them - they had been in for about 10 years!!)

 

[JohnW2]

Not really. One for the DNO.

It's quite an important question, since we frequently tell people that they should contact their DNO about a proposal to install new large loads, but without seemingly having much idea as to how the DNO is likley to react.

If it IS a 100A supply (and not just the rating on the cut-out) it would be difficult to think of a reason why the showers should be forbidden. ... As I have stated before I find the DNO reasoning illogical if fitting 100A supplies but refusing actual 100A demands.

Indeed. However, isn't the issue (from their viewpoint) that DNOs have to take a wider view than just at the level of a single installation. Even if the supply to the installation is adequate for the loads the consumer wishes to connect, that could have wider implications for the network (e.g. neighbours). As I've said before, the thing I find most astonishing is that the 'limit of permitted demand' appears to be an essentially 'unwritten' one - so, as I've said before, the situation is akin to having a speed limit sign which just says 'Speed Limit'!

Kind Regards, John

 

[westie101]

There is no real black and white in these situations as each one is unique.

The capacity of any network is not unlimited and if a free for all developed there is a very high risk of loss of supply or interference with supply quality to other customers. This takes the DNO outside it's licence conditions so at the very least needs monitored.

The other use the add load system provides is that we often visit site to check the cut-out and main fuse size, often these get changed if they are a 60A. This could be seen as a safety improvement to prevent overheating and the risks that brings.