LED Replacements for 12V Halogen Downlights

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E3xtc

773 posts

Ultimate Geek

#173211 15-May-2015 07:02

So I went and grabbed a box of these (ldr12v6l27wg5ap2 lamps) only to install them and find they are flickering....anyone know what the story is there?

Cheers

E3xtc

773 posts

Ultimate Geek

#1305560 15-May-2015 07:30

Hmm so I just read that it can be because the LED lamps are too low wattage....something to do with the transformers requiring a minimum load? Mine are 6W ones whereas the article I was reading said 8W and above usually are problem free....I wonder if the solution is to get a higher wattage bulb?

robjg63

4101 posts

Uber Geek

Subscriber

#1305561 15-May-2015 07:39

Try running 2 off each 12 transformer perhaps?

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

NZSpides

155 posts

Master Geek

#1305563 15-May-2015 07:46

Speaking from experience here.

Replace your switch mode power supply to a LED rated unit.
Just running 2 or more off the old power supply will eventually kill the LED bulbs.

D1023319

524 posts

Ultimate Geek

ID Verified

#1305564 15-May-2015 07:57

I tried led replacement bulbs and had same flickering because of low watts.

So replaced all downlights and transformers with 14w led units from lighting plus @ approx $ 40 each.

They are brighter than 12v halogens and you can insulate over the top with gap.

E3xtc

773 posts

Ultimate Geek

#1305570 15-May-2015 08:23

Thanks all

Not overly keen on replacing all the transformers :( doesn't sound like a fun job (plus added expense) at all (house is 2 storey so htf would I get to the transformers sandwhiched between the two floors?!) Wondering if we just stay with normal halogens if there is no other solution.

Re the wattage - so getting the higher watt lamps fixed the problem and you have not had any other side effect? (eg short lamp life etc) Most of the threads I found talked about getting the 8W or higher; I see Panasonic do a 7.5W lamp, so I wonder if that would be enough :\

razor2000nz

219 posts

Master Geek

#1305575 15-May-2015 08:34

E3xtc: Thanks all

Not overly keen on replacing all the transformers :( doesn't sound like a fun job (plus added expense) at all (house is 2 storey so htf would I get to the transformers sandwhiched between the two floors?!) Wondering if we just stay with normal halogens if there is no other solution.

I was in the same boat as you, halogens run a transformer, LED's run on a driver, so you need to change them, legally that has to be done by a registered sparkie, as for your 2 story part, my house is the same, your downlights should be spring loaded and you just pull them down out of the ceiling, just hope your ceiling gib is strong enough and doesn't break when you pull them through. I have 45 downlighst through out the house, so have changed the 8 (only 4 transformers to swap) in the lounge are as they are the ones that are used most often

Aredwood

3885 posts

Uber Geek

#1306171 15-May-2015 22:17

Electronic halogen transformers output very high frequency AC. Which some LED lamps can't handle. And often have a min required load for them to be able to operate properly. Older style wirewound (magnetic) transformers are fine as the output is just normal 50Hz AC.

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richms

28218 posts

Uber Geek

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Lifetime subscriber

#1306181 15-May-2015 23:10

Except some LEDs will flicker on the low frequancy AC but are fine on a proper DC driver or high frequancy transformer.

IMO its absurd that places are getting away with selling these as a drop in replacement when some transformers will actually overheat with the reactive load of some LED's

Richard rich.ms

E3xtc

773 posts

Ultimate Geek

#1333830 30-Jun-2015 07:39

well after a freaking long time working with Panasonic it would appear the solution (in our case) is to run with higher wattage lamps. The 7.5w lamp Panasonic sells does work for us without the flickering, however Panasonic are very non commital of it working across the board. Their suggestion was to get the house rewired with downlights/amps designed for LED....well it's just not going to happen, with a new(ish) build house - so I have returned them for a refund (thanks PB for helping to sort that end without any restocking fees etc).

So yeah as alluded before I think the fact that they are promoting them on their website as direct replacement for halogen downlights is incredibly misleading.

But in the interests of seeing if the higher wattage lamps works across the board, I have purchased a box of 10 lamps from aliexpress for the same price as 1.5 Panasonnic lamps :\ if it doesn't work, I will just chalk it up to experience...if it does - then woot woot! :)

wellygary

8345 posts

Uber Geek

#1333903 30-Jun-2015 09:39

E3xtc: well after a freaking long time working with Panasonic it would appear the solution (in our case) is to run with higher wattage lamps. The 7.5w lamp Panasonic sells does work for us without the flickering, however Panasonic are very non commital of it working across the board.

Although to be fair, the wide variety of transformers used in houses ( around the world) would make it difficult to test for, and with house wiring usually being done on a very tight budget, Sparkies will generally buy the cheapest gear they can get away with ( especially if it will remain hidden, like a halogen transformer)

But I do agree retailers and manufacturers probably do need to be a little bit more proactive with the

" these bulbs should work, but may not be compatible with all transformers/dimmers)

Fred99

13684 posts

Uber Geek

#1334031 30-Jun-2015 11:49

wellygary:
Sparkies will generally buy the cheapest gear they can get away with ( especially if it will remain hidden, like a halogen transformer)

My son's an apprentice sparky, at the moment doing a lot of domestic new build work. From what he tells me - I doubt sparkies will generally choose to buy the cheapest gear that they can get away with - unless they're masochists. Of course the cheap gear still meets NZS/AS regulations etc - but he hates it. Much more potential for time to be wasted and frustration wiring up fittings etc which are poorly designed, dealing with issues like when something flimsy cracks easily from being over-tightened - so you need to throw it away and start again, removing burred cheap nasty screw heads, or just generally difficult to align, connect cables, etc etc.
I could name a few group housing companies that he detests - but won't because I might get sued. They are the same ones that I hear grouching about from other trades. The housing company tells the sparky what gear to use, very few of the homeowners specify to use something better. Some other building companies specify higher quality fittings - he looks forward to those jobs, as the lack of extreme penny-pinching also usually means that the site is much better organised, with far fewer other problems likely to be uncovered when they arrive on site.