FCU, bathroom light

[nick182]

hey guys,,

ive been asked to wire this bathroom light to an existing FCU for a friend and it turns out that i cant use that FCU.. so would i wire an FCU from an existing socket outlet to the FCU then to the switch? i have looked through all of my books but cant pin point an answer. Im a little concerned as the bathroom is upstairs and so is the socket outlet (which is not protected by an rcd.) The manufacturers instructions are pretty much useless. http://www.heatnlight.co.uk/S451_IB.pdf



I have a lot of idea's as to how i should wire this up but im sure that im missing out on something....
any insight would be of great help

thanks...


Nick

 

[malcolmsanford]

What is the loading on the unit ? Often you can come of the existing lighting circuit with these small bathroom type heaters, via an FCU

 

[Octopus]

If you're adapting a circuit in a bathroom then RCD's are a consideration.

 

[nick182]

manufacturers instructions and it has to be wired that way for warranty purposes...

 

[Deleted member 9648]

As this has a heating element,if coming from the lights you would need to assess the loading of the circuit.
There is no reason why you couldnt feed it from the ring through an RCD FCU....via a pullswitch.

 

[Specialist]

Seen loads of these things & they're normally around the 750 - 1000 watts mark, there also used to be 1 rated at 2000 watts.

 

[nick182]

can i just switch over an existing socket outlet with an rcd type socket outlet then wire it to the fcu then to the switch?

 

[malcolmsanford]

No Nick that would mean that it is just the socket that is RCD protected, not any part of the circuit.

I normally would either try and fit an RCBO for the entire lighting circuit, which in many cases you can't I agree, especially on a rewireable BS 3036 board.

Or fit a stand alone enclosure fed from the existing CU lighting way, and divert the lighting circuit into the enclosure that would have the RCD.

A third way would be to fit an RCD spur into the loop that enters the bathroom lights. I don't personally like that as I feel the regs tell us that the circuits controlling the bathroom needs protecting, but there is an argument that it does not mean that.

 

[Richard Burns]

Malcolm's ideas are the best and the caveats.

The unit seems to be taking about 3.5A so could be wired into the lighting circuit via an FCU, depending on the loading on the rest of the lighting circuit but this does not address RCD protection.
The easiest way to progress would be to take an RCD FCU off the nearby socket circuit and wire the heater into that, take away the lighting circuit currently supplying the bathroom light.
In this way the circuit you have installed in the bathroom is RCD protected, however similarly to what Malcolm says this may then be modifying the socket circuit that should have RCD protection over the whole circuit!

 

[nick182]

looks like i have to notify LABC on this one and issue a minor works.... why does a simple job have to become so rediciously expensive? Arfgggh

thanks guys... if i have any more questions i might hassle you guys later on.

wish me luck

 

[nick182]

what if i were to use a double pole pull chord switch? would that suit the requirements instead of getting the LABC involved and having the customer pay through the nose...?

 

[1shortcircuit]

looks like i have to notify LABC on this one and issue a minor works.... why does a simple job have to become so rediciously expensive? Arfgggh

Try this, how much to install a £5.00 coach light that has already been secured to the wall of the games room at the bottom of the garden. Cable just needs to be sent through wall and wired into switch?

Oh, no RCD protection anywhere and no bonding to Gas or Water lol

My quote £230.00 Their answser? I think not lol

 

[Richard Burns]

Good luck

 

[electromonkey]

Try this, how much to install a £5.00 coach light that has already been secured to the wall of the games room at the bottom of the garden. Cable just needs to be sent through wall and wired into switch?

Oh, no RCD protection anywhere and no bonding to Gas or Water lol

My quote £230.00 Their answser? I think not lol

And that's where Mr DIY kicks in and rather that have peace of mind that their electrical installation has been brought up to a safer standard they'll opt to do the work themselves and "save" their £230!

 

[Octopus]

And just to be contriversal why would fixing a light on the outside wall of a house/outbuilding have any affect on the lack of water/gas bonding. Some of these regs are just plain daft and homeowners can see that.

Now if the homeowner wants extra sockets in the hose that's another matter.

 

[malcolmsanford]

Just being the devil's advocate here in this scenario of installing an outside light in an existing installation, where in the regs does it say ,that if there is no existing Protective equipotential bonding in place you have to fit it.

 

[Geordie Spark]

And just to be contriversal why would fixing a light on the outside wall of a house/outbuilding have any affect on the lack of water/gas bonding. Some of these regs are just plain daft and homeowners can see that.

Now if the homeowner wants extra sockets in the hose that's another matter.

Then we get involved with the added complication of I P ratings !!!!

 

[Richard Burns]

Just being the devil's advocate here in this scenario of installing an outside light in an existing installation, where in the regs does it say ,that if there is no existing Protective equipotential bonding in place you have to fit it.

132.16 No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate.

If there is a fault on the light circuit that may cause extraneous conductive parts to become live then the earthing and bonding must be adequate; therefore if it is not adequate this must be addressed first.
Presumably if this is a class II light then the earthing and bonding would not need upgrading?

 

[Deleted member 9648]

132.16 No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate.

If there is a fault on the light circuit that may cause extraneous conductive parts to become live then the earthing and bonding must be adequate; therefore if it is not adequate this must be addressed first.
Presumably if this is a class II light then the earthing and bonding would not need upgrading?

Just to be picky.....you mean conductive parts

 

[Richard Burns]

Yeah OK, I was thinking only of bonding despite writing earthing and bonding, exposed and / or extraneous conductive parts / CPCs!

 

[malcolmsanford]

132.16 No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate.

If there is a fault on the light circuit that may cause extraneous conductive parts to become live then the earthing and bonding must be adequate; therefore if it is not adequate this must be addressed first.
Presumably if this is a class II light then the earthing and bonding would not need upgrading?

Exactly what I mean Richard I think a lot of the industry blanket do something because it is conceived to be "in the regs", when it isn't.

That is exactly the reg in question and it's the part you highlighted mate, and the words protective measure applied and adequate

I'm not saying that bonding is not desired I think it is, but in this case where as you say it could be double insulated, there would be no chance of your work being near or close to any extraneous conductive parts, and because of the lack of bonding you decided to fit additional protection or it already has additional protection by RCD, do you not think that all of this would comply with the regulation?