Showers

[Deleted member 26818]

Yes absolutely MDJ.
What would happen to that spark if the customer stated that they did not want a pull cord installed?

 

[MDJ]

Thats different, I am just suggesting how it is considered the norm, the guy would really need to phone the office and speak to his supervisor and explain the situation so he isn't looked upon as a clown by the rest of the workforce haha

 

[Engineer54]

The problem I have with DP isolators is:
There is no requirement in the majority of installations for DP isolation.
Isolation in the majority of installations can be achieved by switching the switch on the MCB/RCBO or by removing the fuse.
DP isolation can be achieved in virtually all installations by switching the Main switch.
There are further drawbacks with instaling local DP isolation.
It increases the cost.
It introduces a point which will require inspection in the future.
It introduces a point at which a fault can occur.
It introduces an item of equipment which can fail.
Often these items of equipment are a pain to install.

It's not necessarily the case that the Regs. are being used to limit an installations needs.
It may be that local isolation is not desired for the reasons stated above, or for any other reason.
In such cases, all the Regs. are doing is verifying the installers decision not to provide local DP isolation.

You could attribute those points to just about every electrical installation in one way or another, it doesn't mean they should, or can be used as not to be incorporated in to an installation.

As stated above, any self respecting electrician will include a DP means of ''local'' isolation as a matter of course on a bathroom shower install. As a user i would want to know i could locally isolate the power to the shower, ...and as the electrician i would want to know that when working on the shower, i was in control of the power locally too!! lol!!

 

[richy3333]

There was another recent thread about showers that I posted on, about 'like for like' replacement and RCD protection. Anyhow, I emailed MIRA and this is what their instructions say:

A separate, permanently connected supply must be taken from the consumer unit to the appliance through a double-pole switch, which has at least 3 mm of contact separation. The switch can be a ceiling mounted pullcord type within the shower room, or a wall mounted switch in an adjacent room.


The diagram on the next page (which I can't copy) shows a DP pull cord as an isolation switch.

 

[Deleted member 26818]

You could attribute those points to just about every electrical installation in one way or another, it doesn't mean they should, or can be used as not to be incorporated in to an installation.

As stated above, any self respecting electrician will include a DP means of ''local'' isolation as a matter of course on a bathroom shower install. As a user i would want to know i could locally isolate the power to the shower, ...and as the electrician i would want to know that when working on the shower, i was in control of the power locally too!! lol!!

Yes you can attribute those points to just about every installation.
Not quite sure what the rest of your first sentance is saying.

Any self respecting electrician, would consider whether the benefits of installing such a device outweigh the drawbacks.
You may personally want to know that you can locally isolate the power to the shower.
If you we're the customer, then you would not ask for the isolator to be omitted.
Are you seriously suggesting that the CU would be too far away for safe isolation?
We're talking about a domestic installation, not some factory where the DB is over on the other side somewhere.
Do you not practice safe isolation and lock off MCBs, or remove fuses when working on circuits?

 

[Engineer54]

Yes you can attribute those points to just about every installation.
Not quite sure what the rest of your first sentance is saying.

Any self respecting electrician, would consider whether the benefits of installing such a device outweigh the drawbacks.
You may personally want to know that you can locally isolate the power to the shower.
If you we're the customer, then you would not ask for the isolator to be omitted.
Are you seriously suggesting that the CU would be too far away for safe isolation?
We're talking about a domestic installation, not some factory where the DB is over on the other side somewhere.
Do you not practice safe isolation and lock off MCBs, or remove fuses when working on circuits?

Haha, that would mean that you'd never see any local isolation provisions anywhere. The drawbacks would ALWAYS be used as a reason not to provide!! Especially going by some of the numbty threads and posts on here!! The rest of the paragraph means, that none of your points is an excuse not to provide a means of local isolation on a bathroom electrical shower installation.

Yes we do use safe isolation, but just how many actually/realistically use it in the UK on a Domestic, whether they have the kit or not?? We both know, that a means of local isolation for a high current using appliance in, what is a higher than normal risk area, should always be provided. Sorry, but i can't see any excuses you've put forward so far, that would negate providing that provision.

 

[Deleted member 26818]

It all depends on the purpose of the isolator.
To my mind, there are three/four purposes for providing local isolation.
Functional switching, switching for maintenance/cleaning and emergency switching.
In a domestic installation, is there a requirement for any of these.
With the majority of domestic appliances, there is an on/off switch on the appliance, which provides functional switching.
Switching for maintenance would to my mind be required, but would it have to be provided locally?
Individual circuits can be isolated at CUs and safe isolation practices implimented.
Yes if a number of appliances are connected to a single circuit, it would in most instances be desirable to isolate only the appliance to be maintained, so individual isolation for such appliances would be necessary.
Is isolation necessry for cleaning, I would suggest that in many instances no, however if it is not known what appliance is to be connected to a circuit or what the requirements for cleaning would be, it may be a good idea to provide local isolation just in case.
Is emergency switching really necessary in a domestic installation, what emergency would it be safeguarding against?
In a domestic installation, it's unlikely that there will be rotating machinery that someone could get caught up in.
Is there a likelyhood of electric shock, and would a local isolator be of much use?
Appliances, equipment and fittings can catch fire, for a variety of reasons, would local isolation even be desirable for such an emergency?
If for instance a washing machine caught fire, would it be advisable to enter the room containing it to isolate, or would it be more advisable to have the isolator outside of the room?
If isolation is for emergency switching, shouldn't that isolator also comply with the requirements for an emergency isolator, shouldn't the switch be coloured red for instance?

To my mind, it is not always a case of such and such must be installed.
The pros and cons should always be consider before selecting and installing any item of equipment, and I believe any self respecting electrician would do so.

 

[Engineer54]

We can go round in circles all day, bringing up one situation after another. I think most professional electricians here, will agree that providing a means of local isolation on a bathroom shower install is the way to go, in more ways than one!!

 

[MDJ]

What this thread is showing is the guys at the IET need to ensure those on the panel who write the regs actually need to also have experience on site as well as every qualification known to man within this industry, there are grey areas within B7671 and this IMO is one of them, Spinlondon is 100% accurate with his knowledge regarding the rules, but I totally agree with what E54 has said also as I have mentioned myself a few posts back, this needs to be amended IMO, No-ones wrong here, it is just another grey area and could be the potential for a slanging match with no winners.

 

[Stroppy]

Is emergency switching really necessary in a domestic installation, what emergency would it be safeguarding against? Appliances, equipment and fittings can catch fire, for a variety of reasons, would local isolation even be desirable for such an emergency?
If for instance a washing machine caught fire, would it be advisable to enter the room containing it to isolate, or would it be more advisable to have the isolator outside of the room?

I would say a resounding 'yes'. Unless the fire was raging I would much rather have the option of reaching over the worktop to switch off the spur (or in the lovely cupboard grid-plate), than have to go to the cupboard under the stairs, pull out the hoover and pile of polythene bags, find a torch to look at the consumer unit with, why aren't these damn things ever labelled? Oh crap, now I've turned the lights off by mistake. Luckily I can still see a bit from the brightening glow of my blazing underpants in the kitchen...