appliance isolaters

[FingRinal]

Functional switching is more to do with the normal functioning of a circuit i.e. a light switch is a functional switch. It is not a form of isolation.

That's reasonable for starters. Now dig in and find out what you can about 'Isolation' and Emergency Switching and apply what you learn to a Domestic Electrical installation.

I fail to see where you are going with this, care to explain? Do you mean the main switch is the only required form of isolation in a premises? Not imo a good design if you need to switch off the whole CU in order to carry out work on a dishwasher.

Why do you think 'Isolation' as defined in BS7671 applies to the average domestic electrical installation? What is the purpose of Isolation? When is it required? Where is it required? How is it fulfilled in operation? What are the other considerations of isolation? How is it different to Emergency Switching, Functional Switching? Where can Isolation be provided? If isolation is genuinely required, what about EWR 1989? When would a built-in washing machine (for example) need to be correctly isolated (not functionally switched off) and by whom? And could this isolation be provided elsewhere for this purpose?

There is huge difference btween the need for and providing isolation and the need for and providing functional switching.

I'm not been awkward. If my prose is clinical and comes across that way, I apologize.

 

[JohnD]

not sure your prose style is suited to giving answers and advice to DIYers.

 

[ban-all-sheds]

Personally I think we should leave FR to pore over the regulations looking for reasons why all manner of things are not required in domestic installations while everybody else gets on with designing things on the basis of what is convenient and useful, and then confirming that the design does not contravene anything...

 

[Spark123]

Why do you think 'Isolation' as defined in BS7671 applies to the average domestic electrical installation?

To cut off part or all of the installation for safety reasons?

What is the purpose of Isolation?

To disconnect the relevent part of the circuit from every source of energy

When is it required?

In this instance, where there is a fixed piece of equipment which may require to be dismantled requiring access to live parts in order to carry out work on it.

Where is it required?

Where the designer deems it necessary in line with section 314

How is it fulfilled in operation?

By ensuring the device is securable or local to the item

What are the other considerations of isolation?

Needs to be secure? Remove from all sources of energy?

How is it different to Emergency Switching, Functional Switching?

Emergency switching is for the rapid removal of supply to remove danger i.e. you may find it in a workshop. Functional switching is for functional purposes only i.e. normal operation of the installation, it doesn't need to be securable and does not need to meet the requirements required for isolation.

Where can Isolation be provided?

Where the designer deems it necessary

If isolation is genuinely required, what about EWR 1989? When would a built-in washing machine (for example) need to be correctly isolated (not functionally switched off) and by whom?

Service engineer, someone wanting to clean out the filter, work on a logic board, motor etc.

And could this isolation be provided elsewhere for this purpose?

It needs to be isolated before access to live parts, how the designer goes about it is up to them.

There is huge difference btween the need for and providing isolation and the need for and providing functional switching.

Yeah, functional switching is the normal switching on and off for normal service whereas isolation is the secure removal from sources of energy where access to live parts may be required.

 

[FingRinal]

BAS, I know you practise what you preach, but don't encourage others into slapdash work that wouldn't comply with the Regs in a month of Leap Years.

 

[FingRinal]

So...what's wrong with putting a 'functional switch' which also satisfies the requirements for 'isolation' in a cupboard?

And if you were called to work on an appliance and could not find the means of isolation, would you walk away or use another means of isolation e.g. fuse or mcb for TN systems or DP mcb/main switch for TT systems?

 

[ban-all-sheds]

Emergency switching is for the rapid removal of supply to remove danger i.e. you may find it in a workshop.

And even though a DP switch doesn't meet the requirements for an Emergency Switch, emergencies can arise. Appliances can catch fire, for instance, particularly tumble driers, and if the fire stops you from getting to the knob on the front (if it still works given the fire) I'd not like my only course of action to be to remove all power from the entire house.

 

[Spark123]

BAS, I know you practise what you preach, but don't encourage others into slapdash work that wouldn't comply with the Regs in a month of Leap Years.

So are you saying that installing accessable isolators in a kitchen is non compliant with the regs and slapdash?

 

[securespark]

Secure,

I suggest you keep your private thoughts to yourself. It appears that it is you who is trying 'jump' in on a thread so as to cause havoc.

If you've nothing to add to this discussion, leave it be.

FR - you ARE a contrary beast, aren't you?

As you yourself said, I don't need your permission to post here.

You, my friend, have had "nothing to add" to many a discussion, but it didn't stop you posting.

BTW, you still have not answered my question.

 

[FingRinal]

Emergency switching is for the rapid removal of supply to remove danger i.e. you may find it in a workshop.

And even though a DP switch doesn't meet the requirements for an Emergency Switch, emergencies can arise. Appliances can catch fire, for instance, particularly tumble driers, and if the fire stops you from getting to the knob on the front (if it still works given the fire) I'd not like my only course of action to be to remove all power from the entire house.

Indeed BAS, if my tumble drier burst into flames, I would really fancy walking over TO the tumble drier to reach for the switch conveniently situated just above it or just to the side of it!!!! And then leave the chard installation still connected to the rest of the installation whilst the rest of the installation is live and in use.

Talk sense for crying out loud.

 

[RF Lighting]

 

[securespark]

Talk sense for crying out loud.

Wish you would!

 

[Spark123]

So...what's wrong with putting a 'functional switch' which also satisfies the requirements for 'isolation' in a cupboard?

I don't have a problem using a single device for both functions, however hidden in a cupboard is a bad thing, not exactly accessable with operation, inspection and maintenance in mind (section 513).

And if you were called to work on an appliance and could not find the means of isolation, would you walk away or use another means of isolation e.g. fuse or mcb for TN systems or DP mcb/main switch for TT systems?

Where I work we have drawings and proper formal procedures. I wouldn't condone the installation of a substandard system.

 

[ban-all-sheds]

BAS, I know you practise what you preach, but don't encourage others into slapdash work that wouldn't comply with the Regs in a month of Leap Years.

So are you saying that installing accessable isolators in a kitchen is non compliant with the regs and slapdash?

I suppose he must be.

How odd.

 

[baldelectrician]

From Scottish Building standards Domestic Handbook

Where socket outlets are concealed, such as to the rear of white goods in a kitchen , separate switching should be provided in an accessible position, to allow appliances to be isolated.