Bad ground ?


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Old 04-24-19, 03:57 PM
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Bad ground ?

Installed 24 volt uv light in air handler. Used the magnet to connect to inside of blower cabinet. Tapped into existing red-white of transformer. 27 volts output. When I energized it, the bulb was 1/4 dull red instead of the expected blue. The fan housing where the magnet was connected got real hot in a few minutes. Tell tale odor of burnt transformer. Did not ruin transformer as unit is running minus uv wired in. I disconnected. I got rid of magnet and zip screwed to cabinet. Thought I get some ideas before I wired it in again. Thanks in advance. R. B.
 
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Old 04-24-19, 04:02 PM
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Welcome to the forums.

There are no grounds on that light.
Is that light 24vAC or 24vDC ?
 
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Old 04-24-19, 04:54 PM
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Since you said you attached UV light using magnets, I assume you made your own as I do not know of any HVAC UV light that mounts inside of blower using magnet.

Transformer inside most HVAC system is 24V AC. Is your UV supposed to run on AC?
If it is tube type, it will need a ballast as well. Does it have one ?

Also transformer inside HVAC is not meant for high load and may not be powerful enough to run a UV light. They are only used for controlling few relays and a logic board.


Also, UV light should be mounted in A/C coil as that is where mold is likely to grow. Mounting UV light inside blower cabinet may damage wire insulation as they are usually not rated for UV resistant. UV will quickly degrade wire insulation and most plastic parts.
 
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Old 04-24-19, 06:04 PM
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I suspect the transformer is not big enough to handle the load. What is the transformers VA and what is the load?
 
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Old 04-24-19, 06:13 PM
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The top tech system shows about 26 watts of power consumption but it also comes with its own supply.

Top Tech magnetic UV light (pdf)
 
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Old 04-29-19, 03:32 AM
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Ac
standard 240 volt primary-40va transformer. No need for ground but cannot figure out why mount and surrounding metal go so hot. Of course I’m assuming good ballast and light.
 
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Old 04-29-19, 03:37 AM
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Thanks
standard 220/24V-40 va transformer in air handler. I was leaning trying a separate transformer. Just can’t figure out why mounting hardware and surrounding metal got so hot. Thoughts?
 
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Old 04-29-19, 03:45 AM
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Thanks
most UV lights do have magnetic bases. I have a m coil with a closet with filter rack on out side wall for supply air.(very common in South West Fl.)
tapped into control transformer for heat/ac which is a 40 va, 220-24 transformer. New light with ballast included. 24 v ac bulb
really trying to figure out why bracket and housing attached to got so hot.
Thanks in advance for your thoughts
 
 

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