Shower isolator.

[JohnW2]

Size of plate.

Yep, apparently - as I was told in post #30 (about 15 posts ago). However, as I said, it's a new one (and a pretty confusing one) on me

Maybe it's come to be regarded as accepted terminology by some people, but seemingly only in limited contexts - for example, I've never heard a double socket being described as "2-gang", nor have I heard of 4-gang or 6-gang (actual!) switches being described as "2--gang", even though they all have a plate that fits on a 'double' back box!

Kind Regards, John

 

[securespark]

The plate is described as 1 gang or two gang.

 

[securespark]

It's probably another of those things that some people will say is wrongly described, but I've known it since I started in the industry.

If you Google "2 gang box", you'll get a good number of hits.

 

[JohnW2]

The plate is described as 1 gang or two gang.

I now realise that, but I'm still not surprised that I was confused when I read here of a "2-gang shower isolator".

As I said, you presumably wouldn't describe an (actual) 2-gang or 3-gsng) switch as "1-gang", or an (actual) 4-gang (or 6-gang) switch as "2-gang" on the basis of the size of the plate, would you?

... so what's special about shower isolators?

Kind Regards, John

 

[JohnW2]

The plate is described as 1 gang or two gang.

It's probably another of those things that some people will say is wrongly described, but I've known it since I started in the industry. If you Google "2 gang box", you'll get a good number of hits.

There might have been a bit of a misunderstanding. I am very familiar with 1-gang and 2-gang boxes (and 1-gang and 2-gang plates) and, whilst one might say the terminology is a little odd, I have no problem with it, since it's clear what is meant.

What I don't recall ever having seen/heard prior to this thread (and which I do have "a bit of a problem with"!) is seeing a switch (or isolator) which is electrically 1-gang described as "2-gang" because of the size of its plate.

Kind Regards, John

 

[RandomGrinch]

Just for fun, a quick bit of research on the etymology of 'Gangs' in terms of electrics, brought up the following:

How did the word 'Gang' come to represent the switches in a light switch

When referring to light switches those that have two switches are known as 2 Gang, three switches 3 Gang... and so on. Etymonline doesn’t give details in that respect, nor do other online dictiona...

english.stackexchange.com

Then comes the difference between the US and UK definition of a gang:

What does "1 Gang", "2 Gang", and so forth mean when talking about electrical boxes?

What does a "1 Gang" mean when talking about electrical boxes? Example: CARLON 1-Gang Metal Adjustable Electrical Box (Lowes.com)

diy.stackexchange.com

In the US, the gang size relates purely to the width of the plate.

And as we have seen in this thread, it is suggested that in the UK, 'Gang' has two meanings. One based on the width of a standard socket plate and a different one used to group the number of switches.

Both meanings are 'correct' in terms of the definition of a gang - purely a grouping of components together.

Whether these sources can be verified is another question, but it amazes me that double meanings like this dont cause more confusion!

 

[JohnW2]

Just for fun, a quick bit of research on the etymology of 'Gangs' in terms of electrics, brought up the following: .....
In the US, the gang size relates purely to the width of the plate.
And as we have seen in this thread, it is suggested that in the UK, 'Gang' has two meanings. One based on the width of a standard socket plate and a different one used to group the number of switches. Both meanings are 'correct' in terms of the definition of a gang - purely a grouping of components together.

I know nothing of the US use of this terminology, so nothing I have thought or written relates to that.

In terms of UK usage there are, indeed, two meanings - but, until a couple of days ago, I thought that the two were kept well separated, according to context.

As I've just written above, I am very familiar with the use of N-gang in the context of boxes and plates when, as you say, it refers to the width of the box/plate. However, until a couple of days ago, in this thread, I don't think I'd ever see "N-gang switch" (or, in this thread, "N-gang isolator") to refer to anything other than the existence of N 'switches' (or 'switching units').

If one doesn't keep to that context-dependent separation of the two meanings, all of the anomalies I have been highlting start showing their faces

Kind Regards, John

 

[ebee]

OH DEAR, it looks like I unintentionally caused quite a stir with my remark about shower switches.

OK I will state my personal position on this.
If any isolator/functional switch is added somewhere whether by virtue of regs requirement/contract/personal choice of the designer/installer or the end user/landlord etc I always consider where I believe to be the most sensible place for such use.
So if it can be easily associated by most people as to what it supplies is one consideration so in this case either a pull switch inside the bathroom or a plate switch immediately outside the bathroom door I think.
In addition a neat label on it might be appropriate, especially for the plate switch scenario.
(I think similar for cooker switches too - not too far from the appliance and readily associated with it to most folk. not hidden in a cupboard out of sight).
If anyone wants to switch off rapidly because of a leak or burning etc then nearby/inside the location is the first choice in the first instance. Hopefully the next step should be to isolate at the consumer unit or at least switch off the breaker but, in reality, does not always happen. We could hope it does but often no.

Personally I am not usually a fan of a pull switch for a shower but rather a plate switch immediately outside the door.
I do realise that some, although they should not, would rely on that for isolation for servicing such as removing the cover/making a repair/replacement therefore the pull switch in the bathroom would be safer and more likely put them in control and in sight of the "means of isolation" and for this reason would be a better location overall, despite my slight non-preference.

If someone can switch off quick because of a leak/burning etc very quickly then it gives them time to proceed calmy to the consumer unit and then trip/disconnect the appropriate circuit (of course if that is found to be the wrong circuit because all the lights have gone out you can quickly put them back on and investigate a little more and in a calm manner).
If no local switch is available they might rapidly run like a headless chicken, to the consumer unit and throw the main switch. That should isolate it therefore making it electrically safe, although if no daylight then it could encourage say falling down the stairs and breaking their neck.
So they have died of a broken neck but hey ho are still electrically safe. Hmmm!

Any definite pulling or flicking of a decent switch, especially a 50A one requires more stress on the surface its mounted too, again could be a plus for the plate switch in preference to a pull switch.

Those big Crabtree pull switches seem to be man enough for the job , just a bit ugly.

With any shower then often 6mm T & E is not really a problem.
On the other hand 10mm T & E is a bit more of a problem, plus the final movement of fastening it securely to the backbox puts more stress on therefore encouraging loosening of conductors, despite waggle/tighten/waggle/tighten/waggle/tighten in doing so.

Most showers would probably run OK in practice with just 6mm max conductors despite possible overloading/voltage reduction considerations, mainly because a "normal" shower usage should often be with 10 mins (6 mins ?) and , hopefully, with 20 mins but can we guarantee that folk will not run them for far longer and with what we might consider insane periods of time? NO.
I`ve seen quite a few of the old Dolphin etc showers connected in 2.5 T & E from a bedroom socket which is itself a spur off a ring and it`s been installed for years and no obvious signs of overheated terminals or cables. If I had done it I would be frightened it would burn down within a week.

I have come across (once) one of the older showers that was not solenoid operated and the pressure switch was faulty and ran the heater on until the stat tripped it, then off till cooled down a bit, then on/off/on/off ad infinitum . In fact it had "been like that for well over six months cos you could hear it bubbling every time you went to the bathroom". Oh Dear!
In this case it did have a pull switch and they didn`t know what it was for but would not have used it anyway because that little bubbling noise did not worry them too much anyway.

If someone has other means of heating the water (example a gas boiler) I would indeed advise them that an electric shower is probably not required and would be more expensive to run but some liked it as a back up anyway.

Incidentally, I do consider that the term 2 gang switch was wrong in this instance.
Example a simple 1,2 or 3 gang switch usually fits onto a single size back box and a 4 gang or six gang switch usually fits onto a twin size backbox. With "Grid switches" it is a bit different though.
Two boxes manufactured into one unit is a dual box, although you can buy them as a twin and a single side by side as one box. Other variations are possible.
However, I do take the point that in different areas of the country then different terms might be common, even amongst electricians. Indeed in my area I found it confused some wholesalers when I ask for a dual box and they give me a twin box so have to tell them what I actually mean.

However, I think I would have asked the same question as John did of this well respected contributor on this one occasion.

 

[ebee]

PS I would not bother what terms the USA uses, they seem to get a lot of things wrong with their terms, pronunciation, spelling etc etc even though they are pretty expert at landing on the moon and designing computers etc.

 

[SUNRAY]

...

If someone has other means of heating the water (example a gas boiler) I would indeed advise them that an electric shower is probably not required and would be more expensive to run but some liked it as a back up anyway.
...

they are not as expensive to run as so many on here keep advising.
I did some very simple tests at one of my rental properties comparing a 10.5 KW with a 27KW Worcester combi and the price of the electricity and gas as measured in pence on prepay meters was surprisingly close.

 

[RandomGrinch]

they are not as expensive to run as so many on here keep advising.
I did some very simple tests at one of my rental properties comparing a 10.5 KW with a 27KW Worcester combi and the price of the electricity and gas as measured in pence on prepay meters was surprisingly close.

Yes, exactly. The cost will be similar, as gas is still about 3 times cheaper than electricity. You are using about 1/3 of the kW.
However, I would much prefer the experience of the gas shower, and would probably spend longer in it!

 

[ebee]

OOOHHH that isnawty spending longer in it - you must have money to burn.

Heating up different amounts just to get a 10 min shower might cause variations on kw used though and gas might give better hot/cold/volumes control (I mean volume of water used not the sound of it being used)

 

[SUNRAY]

Yes, exactly. The cost will be similar, as gas is still about 3 times cheaper than electricity. You are using about 1/3 of the kW.
However, I would much prefer the experience of the gas shower, and would probably spend longer in it!

I just don't get this; what is the difference and why would you take longer?

OOOHHH that isnawty spending longer in it - you must have money to burn.

Heating up different amounts just to get a 10 min shower might cause variations on kw used though and gas might give better hot/cold/volumes control (I mean volume of water used not the sound of it being used)

Which hints at the inefficiency of the gas boiler option where one heats water and waits for it to 'come through' then mixes it with cold at the tap and leaves a pipeful to go cold... rather than only heating to the temp required in electric shower with no waste. Oh and no need for a shower pump as so many seem to require now.


From https://www.diynot.com/diy/threads/are-electric-showers-expensive-to-run.596162/ in August 22

I automatically fit an electric shower in my properties. If nothing else, as Harry says it's a plan B for hot water.

There are numerous threads on here offering conflicting advice however an electric shower IS almost instant and wasted water in minimal. For me a shower is about 2 minutes and owning a rental property with an electric shower and a combi with prepay meters it was very easy to do comparitive tests AT PREPAY PRICES with a Worcester combi. About spring last year so not current prices:
Starting electric from total cold and directing to a bucket took about 3-4 seconds to be warm enough to get under. Filling 2 buckets with water (including warming up) took 2min 15 seconds. =6p
Shower mixer tap took 30 seconds to get hot and best part of 20 seconds to set the temperature, that was a whole bucket then 2 more buckets took 1 min 40 seconds = 7p

An hour or so later did a complete repeat, gas was quicker to regulate temperature so not quite a wasted bucket full =6p, electric =7p

Another hour gas = 6p, electric = 5p. Continuing for a repeat straight away G = 4p, E= 6p.

Totals for 3 showers from cold G = 19p, E=18p. Including the 4th shower G = 23p, E = 24p.

Times for filling were not measured for subsequent tests.

What I didn't think to check was the cost of gas powered shower for 2 mins 10 sec which will have to be more than my readings for 1 min 40 sec.

The resolution on the meters is to 1p so I can't be more accurate than that and hopefully explains variations, however bear in mind the electricity cost for running the boiler is not excluded from the reading for electric shower. On no occasion did it register as a cost but of course usage was metered.

My conclusion? from cold electric makes economical sense for my ablution habits of ~2 minutes, added to that less pollution and less water consumed. Also my own usage at home is a 10.5KW heater but I don't like turning into a lobster and it is extremely rare I use it on high power so my costs will be for a lower powered device, something like 7KW possibly.

Anyone spending longer in the shower (someone on here recently mentioned 20 minutes IIRC), gas appears to be more economical, more polution and more water used.

I haven't had a bath for maybe 20 years.

Additionally I have never understood the idea of heating water then cooling it with cold water in a mixer tap... how silly to waste the gas?

 

[ebee]

I just don't get this; what is the difference and why would you take longer?

Which hints at the inefficiency of the gas boiler option where one heats water and waits for it to 'come through' then mixes it with cold at the tap and leaves a pipeful to go cold... rather than only heating to the temp required in electric shower with no waste. Oh and no need for a shower pump as so many seem to require now.


From https://www.diynot.com/diy/threads/are-electric-showers-expensive-to-run.596162/ in August 22

Yes I agree, it does seem a bit daft and maybe it is , as opposed to 17 people having showers immediately one after `tother in which case gas would probably be a clear winner just like with heating a room.

 

[SUNRAY]

Yes I agree, it does seem a bit daft and maybe it is , as opposed to 17 people having showers immediately one after `tother in which case gas would probably be a clear winner just like with heating a room.

Ah well in which case you are possibly correct... but without having any first hand figures to quote from I still believe it's not such a clear winner as Noo Flung/winston tries to ram down our throats.