In article ,
John Greenwood wrote:
What are the options available to me to wire up a cooker hood, I can think
of three ways but whether these are allowed/legal I do not know:

1. Wire it into the lighting circuit, but then there is no accessible
isolating switch.

Neither is there for most lights. It presumably has its own on off switch?

2. Wire it into an FCU hidden behind the hood, but then do I also need an
accessible isolating switch?

Is it possible to wire it such that the cable comes out of the wall into
it - ie behind it? If the cable comes out the top say near the back it's
often the tidiest way to use an FCU or at least cord outlet even when
wired off the lighting circuit.

3. Wire it into the big red cooker switch.

Not a good idea, IMHO.

I don't really want any visible wiring or socket/FCU. I favour number 2,
but I don't fancy adding a separate isolating switch as well.

Can't see why you'd need one.

Anybody help with this?

--
*A bartender is just a pharmacist with a limited inventory.

Dave Plowman London SW 12
RIP Acorn

In article ,
Dave Plowman writes:
In article ,
John Greenwood wrote:
What are the options available to me to wire up a cooker hood, I can think
of three ways but whether these are allowed/legal I do not know:

1. Wire it into the lighting circuit, but then there is no accessible
isolating switch.

Neither is there for most lights. It presumably has its own on off switch?

....but you need a means of isolating appliances containing
motors.

You could use an FCU or an unfused double pole switch,
or a bathroom fan isolating switch (ignoring the 3rd
pole, but it will have an appropriate legend on it).
Some cooker hoods have quite high power fans nowadays,
so check the loading on your lighting circuit first.

2. Wire it into an FCU hidden behind the hood, but then do I also need an
accessible isolating switch?

You need to be able to operate it for maintenance of the
cooker hood, i.e. before you open or take the hood down.
It doesn't need to be accessible for normal day-to-day use.
If it's far enough away (or out of sight) of the cooker hood
such that someone working on the hood could not be said to
be in direct control of it, it needs to be a type of switch
which can be locked off. Bathroom fan isolating switches
are often of this type, although they don't come with the
lock (it engages in two tiny holes either side of the
rocker, which you probably haven't noticed unless you looked
for them, holding it in the off position).

BTW, and plug and socket is also acceptable means of
isolation.

3. Wire it into the big red cooker switch.

Not a good idea, IMHO.

My cooker circuit has been turned into a switched radial
circuit by fitting 3 socket outlets in place of the
original hardwired cooker outlet. One has the oven plugged
in, another has the gas hob ignition plugged in and the
third was for some appliance previous occupant must have
had in the cupboard under the oven. If your oven plugs
into a 13A socket and you don't have electric hob, I see
nothing wrong in doing this.

--
Andrew Gabriel

My cooker circuit has been turned into a switched radial
circuit by fitting 3 socket outlets in place of the
original hardwired cooker outlet.

Provided the MCB/fuse is of a sensible rating, of course. (i.e. a 32A or 20A
B curve). This will usually be the case, although frequently cooker circuits
are wired with higher ratings, such as 40A or 45A, which would need swapping
out. Also, you'll need to prove that the sockets aren't likely to be used
for outdoor portable equipment, as they would need an RCD/RCBO.

Christian.

In article ,
"Christian McArdle" writes:
My cooker circuit has been turned into a switched radial
circuit by fitting 3 socket outlets in place of the
original hardwired cooker outlet.

Provided the MCB/fuse is of a sensible rating, of course. (i.e. a 32A or 20A
B curve). This will usually be the case, although frequently cooker circuits

It is in this case, and 6mm² cable.

are wired with higher ratings, such as 40A or 45A, which would need swapping
out. Also, you'll need to prove that the sockets aren't likely to be used
for outdoor portable equipment, as they would need an RCD/RCBO.

Well, there aren't any RCD's in this house at the moment.
If I get round to it before Part P comes into force, I will fit
a nice new CU with separate RCD protection on each ring, and take
the immersion heater off the ring circuit. If I don't get round
to it in time, it will stay with no RCD protection and with the
immersion heater on the ring circuit forever more, or until it
causes a fire and burns the house down...

--
Andrew Gabriel

Hi Andrew,

Thanks for your reply. I have decided to do the following:

Install a 13A socket behind the cooker hood which will be completely hidden.
The cooker hood will be plugged into this. The socket will be connected to a
visible FCU at worktop level. The FCU being on the kitchen ring circuit.

Does this sound as if it is in line with the regulations?

Thanks,

John

"Andrew Gabriel" wrote in message
...
In article ,
Dave Plowman writes:
In article ,
John Greenwood wrote:
What are the options available to me to wire up a cooker hood, I can
think
of three ways but whether these are allowed/legal I do not know:

1. Wire it into the lighting circuit, but then there is no accessible
isolating switch.

Neither is there for most lights. It presumably has its own on off
switch?

...but you need a means of isolating appliances containing
motors.

You could use an FCU or an unfused double pole switch,
or a bathroom fan isolating switch (ignoring the 3rd
pole, but it will have an appropriate legend on it).
Some cooker hoods have quite high power fans nowadays,
so check the loading on your lighting circuit first.

2. Wire it into an FCU hidden behind the hood, but then do I also need
an
accessible isolating switch?

You need to be able to operate it for maintenance of the
cooker hood, i.e. before you open or take the hood down.
It doesn't need to be accessible for normal day-to-day use.
If it's far enough away (or out of sight) of the cooker hood
such that someone working on the hood could not be said to
be in direct control of it, it needs to be a type of switch
which can be locked off. Bathroom fan isolating switches
are often of this type, although they don't come with the
lock (it engages in two tiny holes either side of the
rocker, which you probably haven't noticed unless you looked
for them, holding it in the off position).

BTW, and plug and socket is also acceptable means of
isolation.

3. Wire it into the big red cooker switch.

Not a good idea, IMHO.

My cooker circuit has been turned into a switched radial
circuit by fitting 3 socket outlets in place of the
original hardwired cooker outlet. One has the oven plugged
in, another has the gas hob ignition plugged in and the
third was for some appliance previous occupant must have
had in the cupboard under the oven. If your oven plugs
into a 13A socket and you don't have electric hob, I see
nothing wrong in doing this.

--
Andrew Gabriel

In article ,
"John Greenwood" writes:
Hi Andrew,

Thanks for your reply. I have decided to do the following:

Install a 13A socket behind the cooker hood which will be completely hidden.
The cooker hood will be plugged into this. The socket will be connected to a
visible FCU at worktop level. The FCU being on the kitchen ring circuit.

Does this sound as if it is in line with the regulations?

Yes, but you don't need the FCU.
If the plug can't be withdrawn without first dismantling or
removing the extractor fan, then a double pole 20A switch
will do (unfused as there is a fuse in the 13A plug).
If you can get to the plug for such maintenance, then you
don't even need the switch. You don't need to be able to get
to the plug or switch easily for everyday use -- they are
isolating switches for maintenance, and not required for
functional switching (hood presumably has its own switches
built-in for that).

--
Andrew Gabriel

Thanks Andrew, all a lot clearer now.

"Andrew Gabriel" wrote in message
...
In article ,
"John Greenwood" writes:
Hi Andrew,

Thanks for your reply. I have decided to do the following:

Install a 13A socket behind the cooker hood which will be completely
hidden.
The cooker hood will be plugged into this. The socket will be connected
to a
visible FCU at worktop level. The FCU being on the kitchen ring circuit.

Does this sound as if it is in line with the regulations?

Yes, but you don't need the FCU.
If the plug can't be withdrawn without first dismantling or
removing the extractor fan, then a double pole 20A switch
will do (unfused as there is a fuse in the 13A plug).
If you can get to the plug for such maintenance, then you
don't even need the switch. You don't need to be able to get
to the plug or switch easily for everyday use -- they are
isolating switches for maintenance, and not required for
functional switching (hood presumably has its own switches
built-in for that).

--
Andrew Gabriel

On Mon, 28 Jul 2003 20:17:28 +0100, "John Greenwood"
wrote:

Install a 13A socket behind the cooker hood which will be completely hidden.
The cooker hood will be plugged into this. The socket will be connected to a
visible FCU at worktop level. The FCU being on the kitchen ring circuit.

I think I might be a little concerned about the environment that would
exist behind the cooker hood. By virtue of the fact it is a cooker
hood one expects the general area to get a bit warm, and maybe laced
with condensation/steam and other environmentally unfriendly options.

That probably doesn't make it a problem for the regs as such, but page
2 of Electrical Commonsense #101 might apply.

The other issue I would raise in this situation is that if you needed
to take the power off that cooker hood fast, do you intend that the
cooker hood has to be stripped before the mains to it can be
disconnected? If so, that doesn't sound like an ideal situation. It'll
be a right royal pain in the butt if the fuse to the cooker hood blows
and you've got to take the whole thing apart to check it out!

Andrew

Do you need a handyman service? Check out our
web site at http://www.handymac.co.uk

"John Greenwood" wrote in message
...
But hang on, can I place a 20A switch in the ring circuit just like a FCU?

snipped

You won't need any FCU in the circuit if you're making the socket in as part
of the ring main. If you're making the socket for the cooker hood a spur
off from the ring main in the kitchen, then a fused spur unit can be placed
beside the socket where you're taking the spur from. Then you take a single
cable up to the socket behind the cooker hood.

As long as the cooker hood can be completely isolated from the electric's,
both live and neutral, for maintenance reasons, then that is all that is
needed. This is why Andrew recommended either a double pole switch which
breaks both live and neutral supply, or a switched fused spur if you were
removing the plug.

A switched fused spur with flex outlet would be the neatest way, as this
means you're only taking one cable from the existing ring circuit, and
connecting the flex in to the switched fused spur, which is quite within the
regulations.

In article ,
"John Greenwood" writes:
But hang on, can I place a 20A switch in the ring circuit just like a FCU?

Yes, switching the spur (and not breaking the ring;-)
You have to have a fuse somewhere, be it in a FCU or in the
appliance plugtop, but you don't need more than one, and
it doesn't have to be at the beginning of the spur.

--
Andrew Gabriel

On Tue, 29 Jul 2003 09:22:48 +0100, "John Greenwood"
wrote:

Point taken Andrew, but how do I wire it so that no plugs/sockets/cables are
visible?

Maybe a couple of ideas:

1) Take the cable thru one of the cupboards at the side of the cooker
hood, and have the socket in there (you do have a side cupboard to the
cooker hood?).

2) Channel down to beneath the work surface, and put the connection in
a cupboard under there.

3) Take the connection up and to the side, wired into a fused spur.

Andrew

Do you need a handyman service? Check out our
web site at http://www.handymac.co.uk

Hi Andrew Gabriel
In you wrote:

But hang on, can I place a 20A switch in the ring circuit just like a FCU?

Yes, switching the spur (and not breaking the ring;-)
You have to have a fuse somewhere, be it in a FCU or in the
appliance plugtop, but you don't need more than one, and
it doesn't have to be at the beginning of the spur.

Stupid question alert....

What's an FCU? (Acronyms escape me sometimes....)

--
Fishter
unhook to email me | http://www.fishter.org.uk/
You're about one brain cell away from being a talking monkey

Stupid question alert....

What's an FCU? (Acronyms escape me sometimes....)

Fused Connection Unit.

And if that hasn't jogged your memory, it is a device the size of a single
socket outlet that combines some or all of the following features.

1. A switch (optional)
2. An indicator light (optional)
3. A fuse (compulsory)
4. A flex outlet on the front (optional).

Christian.