LV Bathroom Downlights

[oldguy]

Just bought 3x25w Halogen bulbs with fittings (IP65), and a 105w tranformer.

Couple of questions :

Can i add another 25w fitting....is it as simple as 4x25w = 100w and transformer is rated at max 105VA (watt)...the transformer has 3 connections fitted in series, do i just extend this for one more?

Also transformer should be wired thro a 30mA RCD, consumer unit has one BUT lights MCB isn't protected by it, is it as simple as moving the MCB for the upstairs lights to the protected side?

thanks in advance

 

[Steve]

Yes, yes and yes. BUT

Consider whether in this age of austerity, halogen is the best light source.

My mum has just had LEDs fitted in her bathroom, they look very modern and give a fantastic light. You need a few more than with halogen, but she had 150 watts of halogen before, now only 18 watts of LED.

And if you go moving the MCB across, consider the effect of a trip on other circuits. For example, you probably have an electric shower on the RCD circuit. What if you were in the shower and it tripped the RCD, taking the lights with it. Now you're standing naked covered in soap in a pitch black bathroom, with no other lights upstairs.

A far more elegant solution in this case would be to provide an RCD fused spur to supply the bathroom lights on its own.

If you move the MCB across, dont forget the neutral.

 

[oldguy]

Steve, thanks, do have an electric shower but it's coming out replaced by mains fed and i was going to use the wiring to supply some underfloor heating.....which i guess still needs RCD protection.

I'll get the RCD fused spur for the lights,

thanks again

 

[ban-all-sheds]

The lighting is notifiable on 2 counts - special installation and special location.

The UFH will also be notifiable on the same 2 counts.

Also re the lights you'll need to consider how you'll comply with parts L and C of the Building Regulations if there's a loft above the bathroom.

 

[ericmark]

You say LV then proceed to talk about SELV so it is apparent you don't know what you are doing. I do think the building regulations have gone OTT with some aspects but considering you don't know what low voltage is I do think in your case you should leave it to some one who knows what they are doing.

50 - 1000 volt AC classed as low voltage.

It will be new install so RCD is required.

Since lights one must do risk assessment and decide if emergency lights are required.

Is it really worth all the hassle?

 

[doorBell]

Don't forget the airplane style lights to guide you down the stairs and a canoe in the garden tied to a tree.

 

[ELZ4742]

Don't forget the airplane style lights to guide you down the stairs and a canoe in the garden tied to a tree.

 

[sparkwright]

Yes, yes and yes. BUT

Consider whether in this age of austerity, halogen is the best light source.

My mum has just had LEDs fitted in her bathroom, they look very modern and give a fantastic light. You need a few more than with halogen, but she had 150 watts of halogen before, now only 18 watts of LED.

And if you go moving the MCB across, consider the effect of a trip on other circuits. For example, you probably have an electric shower on the RCD circuit. What if you were in the shower and it tripped the RCD, taking the lights with it. Now you're standing naked covered in soap in a pitch black bathroom, with no other lights upstairs.

A far more elegant solution in this case would be to provide an RCD fused spur to supply the bathroom lights on its own.

It may be the est solution to replace the lighting MCB for an an RCBO, providing you can get one to fit your existing consumer unit. This will prevent you losing other circuits in the event of a fault.

If you move the MCB across, dont forget the neutral.

A better solution may be to replace the lighting MCB for an RCBO, if you can find one to fit the existing consumer unit. This won't effect other circuits in the event of a fault.

If you cannot get an RCBO, you could fit an in-line RCCB next to the consumer unit, which will serve just the upstairs lighting.
MCB>RCCB>UPSTAIRS LIGHTING

 

[ban-all-sheds]

An RCD FCU would be easier and cheaper.