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Quartz Halogen Lights - New Transformer - Lights now dim

GL1100A

Jan 31, 2021
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Hello. Newbie here with what might be a simple question. Kitchen range hood with quartz halogen lights. The transformer for the lights failed. The failed transformer was 120/1 volt in & 50 watts out. I could not locate a 50 watt unit so I purchased as 120/1 volt in 60 watts out transformer and installed it. Now lights come on but are extremely dim. I would have thought that a 60 watt unit would allow the lights to operate at their normal wattage capacity. What am I missing? Thank you in advance.
 

Harald Kapp

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What is a
120/1 volt
transformer?

Transformers as I know them are rated by input voltage vs. output voltage (e.g. 120 V / 12 V). Halogen lights typically operate from 12 V, so a 120 V / 12 V transformer would be what you need.
I would have thought that a 60 watt unit would allow the lights to operate at their normal wattage capacity.
Right. As long as the power drawn (50 W) is less than the power the transformer is rated for (60 W) all should be good.
There are 2 options:
- Bad transformer. Can you measure the output voltage of the transformer when the lights are on and off?
- Bad wiring. From your phrasing I take it there is more than 1 lamp. Have you accidentally wired them in series instead of parallel? Halogen lamps are normally wired in parallel.

Make and model of the old and new transformer? Can you supply a picture of the old and the new transformer? Maybe of the wiring (only useful if the wiring is clearly visible).?
 

GL1100A

Jan 31, 2021
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I don't have the old transformer anymore but have a photo of it's data tag (attached). Photo of the replacement also attached. The main difference is that the old one had a wiring harness where both the + & - leads ran from and then back into the transformer via a wiring harness. The replacement only has 2 outgoing 12V leads (white wires) The red wires are the + & - that go to the circuit board where I've confirmed that I have 120/60/1 volt power coming in. I have not found one red wire to be + or -.as I've swapped the red wires around with no change. This hood has 2 (ea) 20W lights. I have each one of the white wires running to a light and then taking each light back to a common ground on the hood. The result is a very dim yellow light. Not the bright white light one would expect.
Bad Transformer Data Tag.JPG
Dimmed Lights.JPG
Hood Data Tag.JPG
Replacement Transfomer.JPG
 

GL1100A

Jan 31, 2021
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PROBLEM SOLVED. Harald - your comment about series vs. parrallel got me thinking. As you can see on the replacement transformer there are 2 red wires on the 120 Volt side and 2 white wires on the 12 volt side. I had discovered that with the 2 red it did not matter which was + & which was -. I had assumed that the 2 white 12 volt wires were both hot. Again, it mattered not which was + & which was -. I connected in parallel my red hot to one white wire and my black - wires to the other white wire and everything fired up just fine. Not having a red wire and a black wire (or white & black) is what was tripping me up. Thank you so much for your very kind assistance.
 

Harald Kapp

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I have not found one red wire to be + or -.as I've swapped the red wires around with no change.
That's o.k., the output is AC.
I connected in parallel my red hot to one white wire and my black - wires to the other white wire and everything fired up just fine. Not having a red wire and a black wire (or white & black) is what was tripping me up.
I do not fully understand what you did here but it sounds as you made a connection between primary (hot) side and secondary (12 V) side. That is absolutely dangerous. This is how it should be done:
upload_2021-2-1_6-27-55.png
 

Martaine2005

May 12, 2015
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It looks like both red (HV) 120VAC wires from the new transformer should go to black and white connections on the control box.
The two white (LV) 12VAC go the the bulbs.

Martin
 

GL1100A

Jan 31, 2021
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It looks like both red (HV) 120VAC wires from the new transformer should go to black and white connections on the control box.
The two white (LV) 12VAC go the the bulbs.

Martin
Yes. That is correct and exactly what I did. Thanks.
 

GL1100A

Jan 31, 2021
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That's o.k., the output is AC.

I do not fully understand what you did here but it sounds as you made a connection between primary (hot) side and secondary (12 V) side. That is absolutely dangerous. This is how it should be done:
View attachment 50794
Yes. How you show it on schematic is exactly what I did. Both lights in parallel through the transformer (white wires). Thank you for your help.
 
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