Main fuse upgrade and associated issues

[Callcom]

I'm due to qualify as a domestic installer soon, and my brother, who is fully qualified, will be doing most of this work.

I have a 60A main fuse.
I currently have a typical domestic installation, i.e. cooker, immersion etc, and one electric shower.
Due to distances between hot/cold supply and downstairs bathroom, I want to fit an electric shower there too.
I'm also planning a new en-suite and want an electric shower there as well
i.e. 3 electric showers in total.

I can upgrade to 80A main fuse for free. 100A would cost nearly a grand.

Question: can I run 3 electric showers with an 80A main supply?

 

[Marvo]

Your brother would be the best person to ask as I assume he's familiar with your installation. Without a heck of a lot more details I can't answer any of your question. Ask him about applying diversity as well, what's the chances three showers will ever be running simultaneously in a normal domestic house?

 

[Engineer54]

3 electric showers in what, a typically sized 3 bed house (probably with gas central heating/hot water) .... Ridiculous is a word that quickly springs to mind!! lol!!

 

[Callcom]

3 electric showers in what, a typically sized 3 bed house (probably with gas central heating/hot water) .... Ridiculous is a word that quickly springs to mind!! lol!!

It's a 5-bed detached with no mains gas. The issue is that you need effectively a dedicated hot/cold supply for a pumped shower and the amount of work involved in plumbing that in is prohibitive.

 

[Guest55]

im already feeling sorry for the new to the forum OP after........

domestic installer

you can fit 20 showers so long as not more than 1at a time is switched on.
other than that run them off a combi boiler for considerably better performance.

 

[Callcom]

im already feeling sorry for the new to the forum OP after........



you can fit 20 showers so long as not more than 1at a time is switched on.
other than that run them off a combi boiler for considerably better performance.

Thanks for your answer. Yes, take that point, also diversity. What I'm trying to get are opinions as to what most electricians would advise their customer in this situation. Given that for most of the year it's unlikely that more than two showers would be on simultaneously, but that occasionally, with a house full of guests all three showers might be on, as well as the cooker.

We already have a large, oil-fired boiler, and the cost of a new one installed exceeds £2k. Also a combi would not be advisable given the size of house and water usage.

 

[Octopus]

Why ask here IF your brother IS real?

 

[GLENNSPARK]

and what business have you altering the I N of the DNO bullit?

chances are its a shared supply as well....

 

[Guest111]

and what business have you altering the I N of the DNO bullit?

chances are its a shared supply as well....

Maybe that's why he needs 3 showers,shared with the neighbours.lol

 

[MDJ]

I'm due to qualify as a domestic installer soon, and my brother, who is fully qualified, will be doing most of this work.

I have a 60A main fuse.
I currently have a typical domestic installation, i.e. cooker, immersion etc, and one electric shower.
Due to distances between hot/cold supply and downstairs bathroom, I want to fit an electric shower there too.
I'm also planning a new en-suite and want an electric shower there as well
i.e. 3 electric showers in total.

I can upgrade to 80A main fuse for free. 100A would cost nearly a grand.

Question: can I run 3 electric showers with an 80A main supply?

Congratulations, you should know the answer to your own question then. Out of interest what does your Brother think?

 

[Callcom]

im already feeling sorry for the new to the forum OP after........



you can fit 20 showers so long as not more than 1at a time is switched on.
other than that run them off a combi boiler for considerably better performance.

Thank you for expressing an opinion - you're the only one so far that has. Of the electricians I've discussed this with, answers range from "it must be 100a fuse", to "see how you get on with 60A (the existing one), if it blows they'll replace it free anyway".

Would have been interesting to see what others think.

 

[telectrix]

and what business have you altering the I N of the DNO bullit?chances are its a shared supply as well....

could be that DNO have offered 80A FOC.

 

[Callcom]

and what business have you altering the I N of the DNO bullit?

chances are its a shared supply as well....

It's not. VPN have quoted for the fuse upgrade - free if it's 80A, hence the question

 

[Gavin A]

I'm due to qualify as a domestic installer soon, and my brother, who is fully qualified, will be doing most of this work.

I have a 60A main fuse.
I currently have a typical domestic installation, i.e. cooker, immersion etc, and one electric shower.
Due to distances between hot/cold supply and downstairs bathroom, I want to fit an electric shower there too.
I'm also planning a new en-suite and want an electric shower there as well
i.e. 3 electric showers in total.

I can upgrade to 80A main fuse for free. 100A would cost nearly a grand.

Question: can I run 3 electric showers with an 80A main supply?

No.

AFAIK diversity is not allowed to be applied to electric showers, therefore you would have 98Amps being drawn by 3 x 7.5kW showers on an 80A bullet just from the showers, and that's with a low rated shower.

for 3 showers you really want to be fitting a cylinder... well, what I mean is, getting a plumber in to fit a cylinder and proper hot water system for you.

ps http://www.napitonline.com/downloads/CP 4 07 P 10-11 16th Diversity.pdf

ps working at home so not got the regs with me, but the OSG reference has been given to look it up yourself

 

[Callcom]

No.

AFAIK diversity is not allowed to be applied to electric showers, therefore you would have 98Amps being drawn by 3 x 7.5kW showers on an 80A bullet just from the showers, and that's with a low rated shower.

for 3 showers you really want to be fitting a cylinder... well, what I mean is, getting a plumber in to fit a cylinder and proper hot water system for you.

ps http://www.napitonline.com/downloads/CP 4 07 P 10-11 16th Diversity.pdf

ps working at home so not got the regs with me, but the OSG reference has been given to look it up yourself

Thanks Gavin, that's really helpful, I'll have a look at that. We do have a hot water system, oil-fired, but probably insufficient to run up to three showers as well as supply rest of house. Also pumped showers need a dedicated supply as you probably know and that's the problem - because of the house layout and distance to the showers, it would cost a fortune in plumbing terms.

Thanks again.

 

[guest119]

What is a qualified domestic installer? Do you work for Pickfords?


Boydy

 

[Kate]

Install a contactor switch, one supply from the db to the switch, wire all the showers from that. That way only one shower can operate at once.

 

[Callcom]

Install a contactor switch, one supply from the db to the switch, wire all the showers from that. That way only one shower can operate at once.

That's an interesting idea, thanks.

 

[trev]

Due to distances between hot/cold supply and downstairs bathroom, I want to fit an electric shower there too.

So this downstairs bathroom is pre existing and doesn't have a hot water supply?

 

[skippy2]

Like it or not that animal exists boydy, take the building regs exams and the regs exam and hey presto qualified domestic installer, register with the selected body of your choice and away you go if you are daft enough those with sense get in with a fully qualified sparkie and get experience before setting out on their own.