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#31958 - 12/11/03 06:24 PM Puck lights and transformers  
Electric Eagle  Offline
Member
Joined: Apr 2002
Posts: 914
Alpharetta, GA
I've got a little problem. One of my crews prewired a kitchen for puck lights. There are 16 total on 3 switches. They did fine on 2 sets by breaking them up with 3 to 5 on a line, but one line has 6 20 watt lights. the largest stock 12v ac xfmr I can find is 105 watts.

The manufacturer said we could put 2 60 watt xfmr's on 1 line, but this doesn't work. The way they said to do it was just connecting the output leads from 1 xfmr to the other and the lights, this does nothing - the lights don't come on at all. I tried connecting one lead to one puck wire and a lead from the other xfmr to the other puck wire and the remaining 2 leads to each other and the lights do come on, but they rapidly strobe.

Any ideas? Anyone know of a 120-150 watt xfmr for this purpose?


Work Gear for Electricians and the Trades

#31959 - 12/11/03 06:35 PM Re: Puck lights and transformers  
Electric Eagle  Offline
Member
Joined: Apr 2002
Posts: 914
Alpharetta, GA
I just did a net search and it looks like I should have no problem getting a 150 watt xfmr, but I can't find a small j-box style one locally.


#31960 - 12/11/03 07:25 PM Re: Puck lights and transformers  
Jim M  Offline
Member
Joined: Aug 2001
Posts: 457
Chestertown, MD, USA
You might want to try Seagull. I believe that they have a 150 and a 300W transformer.
www.seagulllighting.com


#31961 - 12/11/03 07:46 PM Re: Puck lights and transformers  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
We install 300 watt transformers but do not forget this would need 10 awg as 300 watts will be 25 amps or maybe you can add an in-line fuse of 10 or 15 amps depending on your wire size.

The six 20 watt lamps will draw 10 amps.

On the parallel transformer set up, did you reverse the polarity and try it?


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#31962 - 12/11/03 09:20 PM Re: Puck lights and transformers  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
I was thinking the same as Bob (iwire), in using a typical dry type power Transformer.

Then you could get sizes of 100 VA, 250 VA, 500 VA and 1,000 VA with Secondary Voltages of 12 VAC, 24 VAC or both!

Definitely need to size conductors per load, and fuse the primary side.
Secondary side could be fused per feeder, or total VA size - but better method would be per feeder.

Scott35

p.s. sorry to post minimal info! reply if more is needed!


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#31963 - 12/11/03 10:32 PM Re: Puck lights and transformers  
harold endean  Offline
Member
Joined: Feb 2002
Posts: 2,233
Boonton, NJ
Bob,

By the way, what kind of wiring would someone use from the transformer to those hockey puck lights? [Linked Image]


#31964 - 12/11/03 11:10 PM Re: Puck lights and transformers  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
I do not know Harold, the transformers I have done where for track lighting and some other types of overhead wiring.

We use MC, 10/2 or 8/2 (or 8/3, 8/2 is not always available)

I am fairly certain that getting any of those hidden in a a "puck light" would be a chore. [Linked Image]

Hopefully no Wagos used. [Linked Image]


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#31965 - 12/12/03 08:17 PM Re: Puck lights and transformers  
straightedge  Offline
Member
Joined: Mar 2002
Posts: 86
Mesa, AZ
Electric Eagle,

I would suggest that on the set of six puck lights. You use two of those 105 watt stock transformers and split the set up three and three.

I have found that you should only use approximately 80% of the availiable 105 watts. Otherwise the life expectancy on the transformer drastically reduces and you will have a service call.

Tev


#31966 - 12/12/03 09:50 PM Re: Puck lights and transformers  
Electric Eagle  Offline
Member
Joined: Apr 2002
Posts: 914
Alpharetta, GA
Straightedge, that's the whole problem. It was prewired all on one line and it's too late to change it.

I've found xfmr's online that are exactly what we need, but I can't find one locally. I guess I'm going to have to order one and wait.

Thanks for the advice everyone.



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