Film-Tech Forum ARCHIVE: Aisle lighting Transformer

This is topic Aisle lighting Transformer in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=011476

Posted by Jeremy Weigel (Member # 4208) on 06-16-2013, 11:42 PM:

Need some input. I have a Tivoli aisle light strip (circa 1993) that uses a 18v AC transformer. The original burned up and I replaced it after checking for any signs of a short. The replacement worked fine for a few days then it too burned up. On examination the primary leads going in to the coil had burned through. So again I checked the entire strand for a short and again nothing. Checked line voltage coming in and it was good as well. Replaced transformer again just a few days ago. Checked voltage both on the primary and secondary and all was good. Came in today to find that again the primary leads had burnt through again.

I still suspect there is a short in the strand. My question is how do I check the light strand for a short with the meter since the bulbs are in parallel? I've ruled out line voltage since there is another transformer running off the same circuit.

Posted by Dustin Mitchell (Member # 372) on 06-17-2013, 01:44 AM:

Is this happening over-night, or do the tivoli lights go out sometime during the day? If its happening only at night, ask yourself what is different then than during the day; for example, maybe when your janitors mop at night water gets into the strip through a crack.

Just a thought.

Posted by Gordon McLeod (Member # 33) on 06-17-2013, 08:11 AM:

I would measure with a amp meter the amount of current being drawn and maybe put a fuse in the secondary

Posted by Louis Bornwasser (Member # 3063) on 06-17-2013, 10:48 AM:

Is every light on? usually a "dead" giveaway. (You might reduce voltage slightly to extend bulb life.) louis

Posted by Tony Bandiera Jr (Member # 2365) on 06-17-2013, 12:20 PM:

I second what Gordon said, and add:

Is this transformer on a dimmer? Many newer transformers cannot handle being on a dimmer, you need to choose a replacement with not only enough secondary current to handle the lights (Plus a bit extra never hurts) AND be capable of being on a dimmer.

I suspect dimmer incompatibility because often (not always, but often) if the PRIMARY burns up it is more due to input voltage issues. Overloads on the secondary tend to fry the secondary first....but there are exceptions.

Posted by Louis Bornwasser (Member # 3063) on 06-17-2013, 02:52 PM:

I think Tony is right.

Posted by Jeremy Weigel (Member # 4208) on 06-17-2013, 07:12 PM:

Thanks for the responses. They are not on a dimmer and there are a few burned out bulbs. The replacement transformer is the exact make/model (Hammond Manufacturing 166M16 Power Transformer)as the original from 1988. I too suspected line input issue since the primary leads are burnt, but the other transformer (the exact same, but original from 1988) is connected to the same 120v circuit and has no signs of overheating. I'll check the strand again for signs of a short.