Immersion Heater Timer wiring.
 

Round at my brother-in-law's house today. He has an airing cupboard on the
landing and inside the cupboard is a fused switch for the immersion heater.
Wiring is conventional :- mains cable goes into the switch and flex goes
from the switch to the immersion heater.
He has bought a digital immersion heater timer from Screwfix so that he can
have the immersion heater coming on and going off automatically during the
summer months when he doesn't use his (oil fuelled) boiler.
He's a bit baffled by the switch and was asking my advice on how to connect
it. For a start there are only two connections inside the timer - for live
in and live out. No connections for neutral or earth. Also the instructions
state that the wiring (in and out) must be solid copper which complicates
matters because of the flex going to the immersion heater.
So...............how would one go about wiring up this timer between the
fused switch and the immersion heater? Any offers? The only way I could
think of would be to ignore the advice on solid copper and still use the
flex. Have cable from the fused switch into a junction box and then flex
from the j.box to the timer. remove outer insulation from the flex and cut
the live wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

Kev

On Wed, 14 Sep 2005 19:07:28 +0100, "Uno Hoo!"
scrawled:

So...............how would one go about wiring up this timer between the
fused switch and the immersion heater? Any offers? The only way I could
think of would be to ignore the advice on solid copper and still use the
flex. Have cable from the fused switch into a junction box and then flex
from the j.box to the timer. remove outer insulation from the flex and cut
the live wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

Er, yeah, kinda! Without seeing the clock I'd be inclined to run the
flex into and out of the bottom of the timeclock, remove the outer
insulation and just cut the live, kind of like you said but without
the JB. Depends how much room there is in the clock though.

TBH, my mate buys loads of electrical crap from Screwfix and it all
looks a bit Heath Robinson as it's all cheap ****e, so dunno really.
Personally, I'd bin it!
--
Stuart @ SJW Electrical

Please Reply to group

In an earlier contribution to this discussion,
Uno Hoo! wrote:

Round at my brother-in-law's house today. He has an airing cupboard
on the landing and inside the cupboard is a fused switch for the
immersion heater. Wiring is conventional :- mains cable goes into the
switch and flex goes from the switch to the immersion heater.
He has bought a digital immersion heater timer from Screwfix so that
he can have the immersion heater coming on and going off
automatically during the summer months when he doesn't use his (oil
fuelled) boiler.
He's a bit baffled by the switch and was asking my advice on how to
connect it. For a start there are only two connections inside the
timer - for live in and live out. No connections for neutral or
earth. Also the instructions state that the wiring (in and out) must
be solid copper which complicates matters because of the flex going
to the immersion heater. So...............how would one go about
wiring up this timer between the fused switch and the immersion
heater? Any offers? The only way I could think of would be to ignore
the advice on solid copper and still use the flex. Have cable from
the fused switch into a junction box and then flex from the j.box to
the timer. remove outer insulation from the flex and cut the live
wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

Kev

I presume that the timer is battery operated - so doesn't needs mains to
drive the clock?

Can he get at the cable feeding the FCU? If so, he may be able to strip the
outer insulation, insulate the earth conductor if it's bare, and cut the
live - feeding the 2 cut ends into the switch. That way he would comply with
the instruction to use solid copper, and wouldn't disturb the flex.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

On Wed, 14 Sep 2005 21:43:19 +0100, "Set Square"
scrawled:

Can he get at the cable feeding the FCU? If so, he may be able to strip the
outer insulation, insulate the earth conductor if it's bare, and cut the
live - feeding the 2 cut ends into the switch. That way he would comply with
the instruction to use solid copper, and wouldn't disturb the flex.

I'd like to see the clock covered by the isolator though, ideally.
Although as it's only a battery powered thing in this instance so
probably not strictly neccesary.
--
Stuart @ SJW Electrical

Please Reply to group

"Lurch" wrote in message
...
On Wed, 14 Sep 2005 19:07:28 +0100, "Uno Hoo!"
scrawled:

So...............how would one go about wiring up this timer between the
fused switch and the immersion heater? Any offers? The only way I could
think of would be to ignore the advice on solid copper and still use the
flex. Have cable from the fused switch into a junction box and then flex
from the j.box to the timer. remove outer insulation from the flex and cut
the live wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

Er, yeah, kinda! Without seeing the clock I'd be inclined to run the
flex into and out of the bottom of the timeclock, remove the outer
insulation and just cut the live, kind of like you said but without
the JB. Depends how much room there is in the clock though.

TBH, my mate buys loads of electrical crap from Screwfix and it all
looks a bit Heath Robinson as it's all cheap ****e, so dunno really.
Personally, I'd bin it!

There isn't really any room inside the switch. You can see it at:
http://www.screwfix.com/app/sfd/sea/...&cd=1&x=11&y=9

I suppose he can feed cable into and out of the switch and then use a jnctn
box to make the change-over to flex for the final run to the immersion
heater.

Kev

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Uno Hoo! wrote:

Round at my brother-in-law's house today. He has an airing cupboard
on the landing and inside the cupboard is a fused switch for the
immersion heater. Wiring is conventional :- mains cable goes into the
switch and flex goes from the switch to the immersion heater.
He has bought a digital immersion heater timer from Screwfix so that
he can have the immersion heater coming on and going off
automatically during the summer months when he doesn't use his (oil
fuelled) boiler.
He's a bit baffled by the switch and was asking my advice on how to
connect it. For a start there are only two connections inside the
timer - for live in and live out. No connections for neutral or
earth. Also the instructions state that the wiring (in and out) must
be solid copper which complicates matters because of the flex going
to the immersion heater. So...............how would one go about
wiring up this timer between the fused switch and the immersion
heater? Any offers? The only way I could think of would be to ignore
the advice on solid copper and still use the flex. Have cable from
the fused switch into a junction box and then flex from the j.box to
the timer. remove outer insulation from the flex and cut the live
wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

Kev

I presume that the timer is battery operated - so doesn't needs mains to
drive the clock?

There is an internal battery that is re-charged from the mains. SFAICR I
think the instructions say that the settings are maintained for up to six
months after power is cut.

Can he get at the cable feeding the FCU? If so, he may be able to strip
the
outer insulation, insulate the earth conductor if it's bare, and cut the
live - feeding the 2 cut ends into the switch. That way he would comply
with
the instruction to use solid copper, and wouldn't disturb the flex.

Yes - that would be a possibility - although I think he would prefer to be
able to isolate the timer by having it on the 'load' side of the fused
switch. I suppose it would be possible to connect mains cable from the fused
switch, through and out of the timer, and then into a junction box where the
flex could be connected.

Kev

In an earlier contribution to this discussion,
Uno Hoo! wrote:


I presume that the timer is battery operated - so doesn't needs
mains to drive the clock?

There is an internal battery that is re-charged from the mains.
SFAICR I think the instructions say that the settings are maintained
for up to six months after power is cut.


Something doesn't stack up there, Kev. How can it get any power from the
mains to charge the battery if there's no neutral connection?
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Uno Hoo! wrote:


I presume that the timer is battery operated - so doesn't needs
mains to drive the clock?

There is an internal battery that is re-charged from the mains.
SFAICR I think the instructions say that the settings are maintained
for up to six months after power is cut.


Something doesn't stack up there, Kev. How can it get any power from the
mains to charge the battery if there's no neutral connection?

Hmmmmmmmm... yes, that didn't occur to me. I'll take another look at the
device next time I'm around there!

Kev

On Wed, 14 Sep 2005 19:07:28 +0100, "Uno Hoo!"
wrote:

The only way I could
think of would be to ignore the advice on solid copper and still use the
flex. Have cable from the fused switch into a junction box and then flex
from the j.box to the timer. remove outer insulation from the flex and cut
the live wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

If you are going for a junction box, how about:

A new piece of cable from the isolator to the JB
Another from the JB to the timer - live out, red sleeved neutral return
Flex from the JB to the immersion heater.

ie, wire the timer like a light switch, and the JB like a ceiling rose.
--
On-line canal route planner: http://www.canalplan.org.uk

(Waterways World site of the month, April 2001)

"Nick Atty" wrote in message
...
On Wed, 14 Sep 2005 19:07:28 +0100, "Uno Hoo!"
wrote:

The only way I could
think of would be to ignore the advice on solid copper and still use the
flex. Have cable from the fused switch into a junction box and then flex
from the j.box to the timer. remove outer insulation from the flex and cut
the live wire and connect that through the timer - leaving the neutral and
earth to continue on to the immersion heater. Seems a bit 'Heath
Robinson'ish' however.

If you are going for a junction box, how about:

A new piece of cable from the isolator to the JB
Another from the JB to the timer - live out, red sleeved neutral return
Flex from the JB to the immersion heater.

ie, wire the timer like a light switch, and the JB like a ceiling rose.

Excellent idea - thanks for the suggestion!

Kev