Triple Pole Isolator query

[ncjharris]

Hi All,

first time poster, long time browser.

Got a quick query that I can't seem to find the answer too.

I have an external security light with a PIR sensor that is wired to Fused Spur switch internally.
The way the switch works is that if it is on, the external light comes on permanently, if it is off, it works on the sensor (i,e, when someone walks outside).

However, I would quite like to be able to override both of these and be able to completely turn it off (i.e. isolate it).

My query is, could a 3 pole switch be used to this end? I've not had a look at the wiring set up yet, as the face plate is plastered into the wall (previous home owner!).

Any help appreciated.

Cheers

 

[riveralt]

Yes you could use a three pole isolator provided the purpose of the fcu is not to fuse down the wiring and is not a requirement from the lamp manufacturers.
3/5Amp Fused connection units are sometimes used when a spur is taken from the ring final circuit (2.5mm T&E) passed through a fcu and the cable is reduced to 1mm T&E.
If this is the case you must leave the fcu in place - though you could add the 3 pole isolator after this.
The requirment of the lamp manufacturers is self explanatory.
So you will need to open the fcu and see what size cable you have inside.

 

[ncjharris]

Gotcha - thanks for the speedy response.

Some of the other 'home improvements' within the building are a bit Heath Robinson, so it will be interesting to see whats inside the current switch.
Probably a connection to the cooker or something............

 

[maltaron]

All of the ones that I have used switch off completely if the switch is off. You need to switch off & on quickly to set auto. If the light does not switch off there must be another switch to isolate it, or the light is faulty.

 

[riveralt]

All of the ones that I have used switch off completely if the switch is off. You need to switch off & on quickly to set auto. If the light does not switch off there must be another switch to isolate it, or the light is faulty.

Yes but until the OP looks behind the fcu it is difficult to know.
The way the OP has described the operation it is possible that the normal fcu load and supply cables have been added to with an additional T&E cable from the supply L & N to the lamp - giving a permanent live and neutral at the lamp so the fcu switch will not totally isolate the lamp.

 

[kai]

It seems a dangerous set up, as someone could believe that the FCU really did isolate that outside light - and receive a fatal shock when they went to work on it.
It is important to get a competant electrician to check and inspect the setup you appear to have, the FCU not isolating the light properly.

 

[ban-all-sheds]

It seems a dangerous set up, as someone could believe that the FCU really did isolate that outside light - and receive a fatal shock when they went to work on it.

That's Darwin's way of teaching the importance of safe isolation.