2 Electric Showers in 1 House

bmowner

thanks

2011

1. what are the implications of not having the priority controller

You could blow your main fuse! If the wiring is poor this may be the least of your worries.

2. what does the controller do?

It only allows 1 shower to be switched on at a time so the system can not be overloaded

3. where should it be placed?

Normally in the board. It can be placed other places.

4. should the new showers have separate fuses on the fuse board i.e. the 2 new showers appear to share the one fuse.

If only 1 can operate at one time then one MCB would be OK. Instantanious showers (such as yours) must be protected by thier own RCD (or RCBO) and not share one with the sockets. This is a regulation and very important!

5. are there health and safety issues?

With the way yours seems to be wired? I would think so.

As davelerave suggested I would get this checked out if I were you by a registered electrical contractor.

rugbyman

Hello Lads,
i need some simple advice. i am sure I could search threads and find it ,but ,bear with me,

My family are intent on bankrupting me with esb bills, we had an electrically heated shower(all of it is visible on the wall). it is called a Heat Store ,aqua plus.

for several years it was our only shower and was adequate,never piping hot, but ok.

when we built a new bathroom we went for one that uses the hot water from the tank(heated by the oil or electric). i imagine this is powered proppelled as it is on the same level as the hot water tank.

everyone in the house uses this one(as it is hotter) and the immersion is regularly switched on and left on for days. faced with enermous bills I was considering getting a modern one thats heats cold water as it is needed.

A what is approx cost of such an appliance, (just to buy, not fitted)

B how much might it save me in a year on electricity ( 15/20 showers per week)


regards,rugbyman

davelerave

you have a mixer shower or a power shower. so you could look at heating the water efficiently if possible by zoning the DHW separately and insulating the HW cylinder first.otherwise prob a 'pumped' instantaneous electric shower if possible .i don't know the cost

Joey the lips

rugbyman wrote: »

Hello Lads,
i need some simple advice. i am sure I could search threads and find it ,but ,bear with me,

My family are intent on bankrupting me with esb bills, we had an electrically heated shower(all of it is visible on the wall). it is called a Heat Store ,aqua plus.

for several years it was our only shower and was adequate,never piping hot, but ok.

when we built a new bathroom we went for one that uses the hot water from the tank(heated by the oil or electric). i imagine this is powered proppelled as it is on the same level as the hot water tank.

everyone in the house uses this one(as it is hotter) and the immersion is regularly switched on and left on for days. faced with enermous bills I was considering getting a modern one thats heats cold water as it is needed.

A what is approx cost of such an appliance, (just to buy, not fitted)

B how much might it save me in a year on electricity ( 15/20 showers per week)


regards,rugbyman

I dont know to be honest but this is not the way i would sell showers. To improve your situation I think you need an immersion timer to stop it running away with itself.

There is 2 ways to look at a shower there is stored demand and created demand

Stored demand is usually a power shower, what you seem to have. Water is stored hot in a cylinder and is planned and ready for use. This can lead to a wastage of water and so an immersion timer is rec. This option is very economical in the winter as most people would have there heating on anyway

Created demand. This is a triton T90/Mira Elite 2. Water is created as required. There is no stored hot water. This is an excellent summer alternative as no hot water is needed to be stored. As water is created as required it usually allows for visitors.

I think an immersion timer will sort you but hope this explains more

http://www.boards.ie/vbulletin/showthread.php?t=2055553663&highlight=Power+shower

rugbyman

thanks Joey, have admired your name for some time, you are on many threads, sounds like some one from the Sopranos.

have read part of your informative link.

i have a timer set on the immersion, and on the oil in winter, both of which leave us with piping hot water , the family override the timer and switch the immersion on and leave it on. part of my problem is that the timer and switches are upstairs in the hot press. i should have had them fitted downstairs and in view.

thanks again
rugbyman

Joey the lips

rugbyman wrote: »

thanks Joey, have admired your name for some time, you are on many threads, sounds like some one from the Sopranos.

have read part of your informative link.

i have a timer set on the immersion, and on the oil in winter, both of which leave us with piping hot water , the family override the timer and switch the immersion on and leave it on. part of my problem is that the timer and switches are upstairs in the hot press. i should have had them fitted downstairs and in view.

thanks again
rugbyman

Joey the lips = The Commitments. I thought jimmy rabbit was a bit to much!


Makes no difference what you do the override is a push of a button and you wont notice. I think the problem your having is the cost. This is a common problem and unless you encourage them to shower together like they did when they were young you have no chance of controling this. There is a sneeky solution but i dont rec it. i once knew of an electrician that disabled the bath element(The bigger one) of the immersion and only had the sink element working. I dont know how this turned out but its a way of slowing down the heating.

davelerave

the DHW zoned separately 'year round' is prob the best way if possible(off the boiler). if you're going down the electric water heating route you can consider 'nightsaver and economy 7 timing'.

2011

you can consider 'nightsaver and economy 7 timing'.

Do you mean the E7 units? I can see the advantages of dual tariff metering, but I see no advantage with the E7 units. I think there are far better ways to save money heating water electrically.

davelerave

i mean the horstmann type timer .with the bath element on the off-peak and the sink for 'boost' or 2 single elements .what did you have in mind for off peak water heating .do you mean something with more flexible timing?

2011

i mean the horstmann type timer

That is what I thought, I dont like them. Thats just me.

what did you have in mind for off peak water heating

What you can do is this:


Install a 2 channel digital time clock like this:


One channel can be for the lower 3kW element (or bath element) and the other element can be for the higher (or sink element). The time clock is only rated for about 3A so a contactor for each element is required (a 25A will last yonks). In series with the switch wire form each channel a tank stat can be wired. This means that the owner can easily set the desired water temperature for DHW and save money.

Tank stat:





An interlock should be installed to ensure that both contactors cannot be energised at the same time. The tank stats ensure that the elements are off once the desired temperature is reached even if the time clock is "calling" for heat.

What are the advantages of this?

1) The bath element can be programmed with the timer to only come on during off peak

2) The immersion is less likely to be left on by mistake. There is a red LED for each channel on the time clock.

3) In the event of power loss the timer has battery back up (unlike the APT timers).

4) The traditional immersion timers (APT type) fall apart/die after a year or so.

5) There is a boost facility for both elements.

6) There is a holiday setting, so you can switch it off for the duration of your holiday and come home to hot water.

7) Easy to read aesthetically pleasing back lit display.

do you mean something with more flexible timing?

Yes, and I think this is user friendly and saves money. Also It gives the owner the option of overriding the system i.e. the bath element can be switched on during peak if required. Sometimes you really want that shower no matter what it costs!

davelerave

prob. 'pre-insulated cylinder' and dual elements anyhow for efficient off-peak electric water heating.obviously the newer combi boilers (instant HW) or condensing boilers (with large pre-insulated cylinder)or even just zoned DHW are the preferred choice .there's also back boilers and solar and prob more.electric would be last choice or backup only except for instantaneous showers imo

2011

I would agree davelerave, but if for what ever reason it is decided to heat DHW electrically control becomes an important issue. Good control does not just heat the water to the correct temperature when you want it, it also saves you money.

2011

OP, what did you do in the end??
Please keep us posted

bmowner

regarding the two new electric showers making three in the house, electrician says regarding two on same fuse that each shower is 600 volts or watts or something similar and that the fuse can take up to 3,000 volts or watts etc. That there would only be a problem if two showers were turned on at same split second otherwise they can run successfully at the same time. does this sound ok?

davelerave

it doesn't make any sense to me anyhow .600 or 3000 whatever doesn't correspond to instantaneous shower ratings .if your 3 instantaneous showers run simultaneously on a regular 63amp single phase supply you have a problem.

Joey the lips

bmowner wrote: »

regarding the two new electric showers making three in the house, electrician says regarding two on same fuse that each shower is 600 volts or watts or something similar and that the fuse can take up to 3,000 volts or watts etc. That there would only be a problem if two showers were turned on at same split second otherwise they can run successfully at the same time. does this sound ok?

I know what your saying although its not making sense to you. What he says is right but if he is an electrician he should be following protocal and fitting a priiority switch to prevent accidental switch by children.

Dont say you have no children you are responsable for correct electrical safety and as such are deemed negligent so is the electrician

With the greatest of respect if the electrician did not rec this s/he either is not an electrician or you have not consulted on.

Any electricians to this post are free to correct me of course

bmowner

ok, did a search on web and the numbers appear to be completely wrong. Is the principle ok however, i.e. two showers with smaller wattage or voltage to the fuse capacity

bmowner

joey got your post after my last post.

one of the showers will be used by children. however the user type doesn't matter surely. if everything is ok (assuming my electrician friend is correct) except for that contempouraneous turning on of the two showers, the question is, what happens if the two showers are turned on contemporaneously?

davelerave

with all due respect to joey he is not a sparkie and is not making much sense.it's simple enough.if you can operate 3 or even 2(less so) instantaneous showers simultaneously on a standard supply you have a problem.should take 2 minutes to establish.main fuse or tripswitch is 63amp single ?? 2 or 3 instantaneous showers operate simultaneously or not??

Joey the lips

bmowner wrote: »

joey got your post after my last post.

one of the showers will be used by children. however the user type doesn't matter surely. if everything is ok (assuming my electrician friend is correct) except for that contempouraneous turning on of the two showers, the question is, what happens if the two showers are turned on contemporaneously?

I had to look up contemporaneously. You mean together!

There is many risks including FIRE and this is a major risk! But unfortunatly what you are asking is bordering on legal or medical type advice.

As i said if your "Electrician Friend" has advised you not to fit a priority switch either s/he does not understand or is very reckless

and if you want to risk your kids standing in an electric shower with water running everywhere thats fine but there is something fishy here!

Joey the lips

davelerave wrote: »

with all due respect to joey he is not a sparkie and is not making much sense.it's simple enough.if you can operate 3 or even 2(less so) instantaneous showers simultaneously on a standard supply you have a problem.should take 2 minutes to establish.main fuse or tripswitch is 63amp single ?? 2 or 3 instantaneous showers operate simultaneously or not??

Dave if I am wrong I apologise I am going on the advice of electricians I had working for me.

2011

it's simple enough.if you can operate 3 or even 2(less so) instantaneous showers simultaneously on a standard supply you have a problem.

This is 100% correct.

The regulations are very clear on this.

You also need to check out the situation with regards to RCD protection as stated earlier.

Randyleprechaun

Both showers must be fed from the same electrical board. Simplest way is(and cheapest)Get a 40A 4pole contactor(2n/o +2n/c).Feed your priority shower through the n/c contacts and your slave shower through the n/o contacts. Instead of putting a pullcord at the slave shower, put a time lag switch instead. Set it for about 15 mins. When you press the timelag it will energise the the contactor thereby closing the n/o contacts and supplying power to the shower. The time lag will automatically return power to the priority shower after about 15 mins.

I can draw this for you if you want. have it done in my own house and the timelag does away with the need for an isolator at the slave shower as the contactor is the isolator.

Regulatory bodies are happy with this setup.

Randyleprechaun

See wiring diagram attached

davelerave

Randyleprechaun wrote: »

Both showers must be fed from the same electrical board. Simplest way is(and cheapest)Get a 40A 4pole contactor(2n/o +2n/c).Feed your priority shower through the n/c contacts and your slave shower through the n/o contacts. Instead of putting a pullcord at the slave shower, put a time lag switch instead. Set it for about 15 mins. When you press the timelag it will energise the the contactor thereby closing the n/o contacts and supplying power to the shower. The time lag will automatically return power to the priority shower after about 15 mins.

I can draw this for you if you want. have it done in my own house and the timelag does away with the need for an isolator at the slave shower as the contactor is the isolator.

Regulatory bodies are happy with this setup.

good simple arrangement ,contactor is normally de-energised.(shower fed through n/o contacts has priority).i would be dubious about contactor(edit)providing isolation though.

2011

i would be dubious about control circuit providing isolation though.

The control circuit is not designed to provide isolation.

The regulations state that instantaneous showers must have local isolation provided by a DP switch (normally rated a 40A). It is not permitted to provide isolation for such an appliance at the distribution board only.


I see nothing wrong with this method.

I would rather use a 63A contactor just because I like to over size contactors, they last years longer. I also think it is better to use 2 way switches rather than a time lag switch. The time lags never seem to last and time out just when you need them most!

TheZohan.

Great info here regarding a second shower.

Thank you.

Zoe

davelerave

2011 wrote: »

The control circuit is not designed to provide isolation.

The regulations state that instantaneous showers must have local isolation provided by a DP switch (normally rated a 40A). It is not permitted to provide isolation for such an appliance at the distribution board only.


I see nothing wrong with this method.

I would rather use a 63A contactor just because I like to over size contactors, they last years longer. I also think it is better to use 2 way switches rather than a time lag switch. The time lags never seem to last and time out just when you need them most!

isolator would be a mechanical switching device isolating the supply.in suitable proximity to shower .by my reckoning.
not sure about this 2-way switching of contactor.timelag would be priority .2-way switching would be non-priority but contacts are likely to be changed over and back causing nuisance i think???

2011

isolator would be a mechanical switching device isolating the supply

Yes and a regulation. This is how you should isolate the appliance.

i would be dubious about control circuit providing isolation though.

I dont know what you mean here. As explained above the local isolator is provided for isolation.

2-way switching would be non-priority but contacts are likely to be changed over and back causing nuisance i think???

Sorry, I dont follow this either. What do you mean "nuisance"?

With a 2 way switch outside each bathroom either shower can be selected. If the isolators have neon indication it will be clear to the user which one has been "selected".