GU10 lights for the bathroom

[DarrenSL]

It seems by far the most common downlighting option for the bathroom is to use LV dichroic lamps.

However, I have noticed one or two manufacturers which produce IP65 mains voltage GU10 downlighters. Given that these don't require transformers and are significantly cheaper why would anyone want to install the low voltage type?

 

[ban-all-sheds]

1) For the same reasons as they prefer ELV lighting anywhere else.

2) Because if you want lights in Zone 1 they must be ELV.

 

[DarrenSL]

Isn't the ceiling zone 2?

 

[jondiy]

Depends how high it is! Is it higher than 2.26 metres?

 

[Adam_151]

2) Because if you want lights in Zone 1 they must be ELV.

...or protected by 30ma RCD,

(either way, SELV or not, they must be IP44 sealed)

Though I don't like the sound of lights on RCD especially in the bathroom (stumbling out of the shower with soap in your eyes dripping wet and trying to navigate a tiled floor that has clothes and towels left on it, in the pitch black sounds like a recipe for disaster to me...)

 

[DarrenSL]

Depends how high it is!

Good point! The floor to ceiling height is 2.36m but bath to ceiling is obviously shorter.

Eitherway, looking at the lights again they're zone 1 compatable.
http://www.lightsaver.co.uk/shop/?page=main_shop.php&whichmenu=bathlig&scrollcat=SL
At £10 each with no transformer required, they seem a bargain to me.

So, back to the original post ... what advantage do dichromic lamps have (other than lifetime)?

 

[Adam_151]

Cleaner crisper light, I also heard you get more lumens per watt, but not sure how true that is

 

[DarrenSL]

Thanks for the replies guys.

 

[ebee]

Cleaner crisper light, I also heard you get more lumens per watt, but not sure how true that is
I can verify that or at least the perceived difference to the human eye (and mine as well) is about 30% ish
Conversely the mains one`s are hotter and enclosed (IPX4) makes all of them run hotter still.
LED lighting come on down, the price is right - or when it is there will be millions of installs

 

[ban-all-sheds]

Depends how high it is!

Good point! The floor to ceiling height is 2.36m but bath to ceiling is obviously shorter.

Eitherway, looking at the lights again they're zone 1 compatable.
http://www.lightsaver.co.uk/shop/?page=main_shop.php&whichmenu=bathlig&scrollcat=SL
At £10 each with no transformer required, they seem a bargain to me.

FYI - the wiring regulation say that unless you cannot reasonably install them elsewhere you may not put them in Zone 1.

So, back to the original post ... what advantage do dichromic lamps have (other than lifetime)?

Dichroic refers to the type of lamp envelope, and is nothing to do with whether it is ELV or LV - you can get ELV dichroic and non-dichroic, and ditto LV.

For LV halogen lamps there are 2 common types of base, GZ10 and GU10.

GZ10 lamps are the dichroic (cool beam) type, where a lot of heat comes out of the back, and GU10s have internal reflectors (the lamps are also known as PARxx - Parabolic Aluminium Reflector<size>) where the heat comes out forwards.

If you look you'll see that you can put a GU10 lamp in a GZ10 fitting, but not the other way around. This was done so that you couldn't put a dichroic lamp into a luminaire designed for PAR lamps, as the rearward-reflected heat would damage it.

Well guess what - people have now started making dichroic GU10s

If a luminaire has a GU10 base, then unless the instructions explicitly say otherwise, you must only use PAR GU10s in it, not dichroic.

The same rule would apply to ELV luminaires.

Be warned that a PAR lamp directly above someone standing in a bath might be uncomfortably hot.

 

[DarrenSL]

Quality response. Cheers!

unless you cannot reasonably install them elsewhere

What constitutes 'reasonable'. Sounds like the regs are open to interpretation?

 

[Adam_151]

What constitutes 'reasonable'. Sounds like the regs are open to interpretation?

...Yes, its not particulary clear cut, a bit like the regulation that calls for RCD protection on outlets resonably expected to supply portable equipment outside the equipotential zone, that causes problems, is it reasonable for someone to throw an extension out an upstairs window or not, etc