Extra Low Voltage: 10 out of 30 downlights dont work. Guidence Needed Please.

[Nick182]

Hey guys,

Background: Im new to the game. New to the forum I have just completed level 2 and 3 city and guilds 2330 and 17th edition. Had no luck gaining employment So I have now gone self employed. eeek

Anyways, Long story short. Could someone shed some guidence on the subject of E.L.V systems and transformers in a commercial shop?

Heres my situation.

My client who owns a massage/spa/Fish pedicure place (including 6-8 fish tanks) has a problem with 10 random 35W (either gu10 or MR16) downlights

-10 downlights in 3 rows

- Dimmer switch (which needs replacing.) Is rated at 500w/400va

-Theres no where accessible to change the transformers and I didnt have a ladder big enough to check the transformer rating which im guessing is now connected to the downlight.

-Lamps have only recently been changed by the maintenance man.

According to the (3phase) Circuit Board chart theres:

Shop lighting one Theres 19 points served. So I am also guessing this would be the circuit for the downlights.

Shop Lighting two Theres 9 points served.

Shop lighting three Theres 5 points served.

Window Lightingtheres 6 points served.

With all rated at 10A protective device.

Here are my questions:

A) If theres no where accesible for the transformers and theres no transformers on the back of the downlight. Would this mean that I have to get up on the floor above and start ripping off the floor boards to access these? I dont see any other way

B)Im replacing the dimmer switch as of monday morning. It seems perfectly rated for the job at 500w, however the middle nob doesnt work and as it so happends in that row. Only 4 of the lights dont work alongside each other. Would changing the dimmer switch help at all or does it just narrow it down to the transformers being faulty?

C)What else should I be checking for?

D) What should i expect to find

and last but not least...

E)With the downlights being so close to the transformer Or close together. Would there be any Transient Voltages or disturbances from that particular or other circuits to create a surge causing the lamps to go out?

AnyHelp/Guidence/Constructive critism would be much appreciated.

thanks in advance.

Nick:Salute

Ps I havnt spent much time on this subject at college or out in the field for that matter. so I would love some assistance and to gain the experience and knowledge from the guys who know how. As u can probably guess i am quite nervous having this job be my first and being out on my own. Im literally quite S******g myself. Question is. Can I swim? we shall see.

thanks.

 

[SLIPSHOD & SLAPDASH]

You firstly need to find out if you have GU10 OR mr16, no trannies on GU10

You have not explained yourself very well, You dont know where the transformers are, but dont have steps tall enough to check the rating ? The 12v lampholders often fail before the transformers.

Are they GU10 or MR16 or a mixture ?

 

[Andy™]

MR16 connections fail often

 

[NozSpark]

Agree with the above..

Get your self a load of MR16 fly leads, some 60vA transformers and lamps........and a bigger set of ladders,, you'll need them in the future

 

[Evans Electric]

Nick182 if you're an Aussie then you have to be called Bruce .

And in case you're not used to them , 95% of downlighter transformers are flexed in just before the fitting , so remove fitting , keep pulling cable through hole and trannie should follow . As the others have said , the lampholders and flexes on the 12V fittings tend to carp out with the heat.

The other 5% of downlighter jobs have a great stonkin' toroidial trannie with spider wiring to the fittings . These tend to have start up inrush problems and are bettter with HRC fuses. IMHO