Dimmer Switch Dilemma!!

[BC-Electrical]

Afternoon, this is my first post on the forum as im new to the site and to the industry so bare with me if this warrants a blatently obvious answer!!

He has 6 downlights which are running off of a dimmer switch, the dimmer switch recently gave way when he went to switch on the light which tripped the MCB in the C.U., he then changed the dimmer switch and the same thing happened again blowing the internals of the switch.

I know this could be down to it not being the correct rating or it being affected by the 50% correction, however i have no information on what type of bulbs hes using, whether or not they are ELV and running off a transformer and what the total required load is, and i wont know this info until i get round there this evening.

My question is i may have time to pick up a new dimmer switch from screwfix on route, shall i just go for a 1000W rated component and over compensate or will this effect the way the lights operate i.e. too dark or too bright, will it start blowing bulbs for no reason!!

If not this any other suggestions



Cheers

 

[Max1]

I would stick a normal switch on first and see what happens!

 

[Adam W]

I would stick a normal switch on first and see what happens!

:iagree:
I'd prepare to do some testing as well. Remember to remove any transformers and bulbs before you IR at 500v; I would IR at 250v first to test the water.

 

[Max1]

Don't think I explained that properly lol. I meant put a switch on while you look into the fault.

 

[jaydee81]

id be removing lamps and doing insulation resistance test on lights first could be burnt cable behind downlights causing fault when lights switched on

 

[telectrix]

If he has halogens and you take a 1000watt dimmer, make sure to take a deep back box as well.

 

[jay b]

Get a MK 400watt dimmer they work well with both voltage and come with a sandwich plate so no need to put a deeper box in. A quick solution if doing job on way home and screw fix do them

 

[BC-Electrical]

Id love to test the circuit for IR however i dont have a tester to hand so any testing is out of the question at present!!

He said the downlighters have been in place for around 2ish years with fresh cable so shouldnt be any issues as far as thats concerned although i will certainly be checking it for wear and tear.

Telectrix - im assuming the deep back box is used to take into account excessive heat from a 1000W switch, other than heat will there be any other issues with using a 1000W switch??

What tolerences or corrections would i have to take into account if hes using ELV fittings with a transformer and how does it differ depending on what bulb hes using??


Cheers for quick replies by the way

 

[Adam W]

You seem to be assuming the dimmer is at fault, specifically the type of dimmer.
I would have said there is something else which is causing the dimmer to fail; my money would be on a new dimmer failing straight away, which is just a waste of money.
If you don't have an IR tester you could at least test continuity with a bell set.

 

[BC-Electrical]

Get a MK 400watt dimmer they work well with both voltage and come with a sandwich plate so no need to put a deeper box in. A quick solution if doing job on way home and screw fix do them

Ahh thank you i may have to go down this route, first thing is ill check what rating the last one was that burnt out, if that was 400W i may have to go bigger depending on what bulbs hes using.

Adam W - i have a voltage tested with a wander lead i could use to check for continuity and polarity which i was intending on doing anyway, if results come back as they should what would your next move/thought be as to why the switch is going bang??

 

[Adam W]

As I said, I don't think your results will be what they should; you could disconnect everything so you've only got one light in the circuit, then start adding them until you find the problem.
Changing the dimmer should be the last thing you try, after you've got all the lights working without it.

 

[Octopus]

Id love to test the circuit for IR however i dont have a tester to hand so any testing is out of the question at present!!


Cheers for quick replies by the way

Do you actually own a tester?

 

[BC-Electrical]

As I said, I don't think your results will be what they should; you could disconnect everything so you've only got one light in the circuit, then start adding them until you find the problem.
Changing the dimmer should be the last thing you try, after you've got all the lights working without it.

Thats a good shout actually, ill go by process of elimination and if its one of the downlighter units ill go about replacing that aswell!!

Murdoch - I dont own a tester personally , yet, however my soon to employer does have the equipment which i will obviously have at my disposal when im on site. I will be investing in a Megger Multi-tester within the next couple of weeks for sure though!!

 

[Harryb]

Don't bulbs go in the garden? Haha

 

[Octopus]

Thats a good shout actually, ill go by process of elimination and if its one of the downlighter units ill go about replacing that aswell!!

Murdoch - I dont own a tester personally , yet, however my soon to employer does have the equipment which i will obviously have at my disposal when im on site. I will be investing in a Megger Multi-tester within the next couple of weeks for sure though!!

So you are going round posing as an electrician without a MFT?? Not ideal is it?