120VAC halogen double confusion


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Old 12-21-16, 02:31 AM
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120VAC halogen double confusion

I recently moved into a house with a ceiling fan that works fine except for the light. It's a 120 VAC halogen fixture, and always has 120 VAC across the terminals regardless of the wall switch position. It also never illuminates the bulb, regardless of wall switch position (I've tried 3 bulbs).

I could buy that there's a problem with the wall switch, but I don't understand why the bulbs are never illuminated when there's 120 VaC across the terminals. Do halogen fixtures always keep voltage across the terminals, but limit the current if the switch is off or something?

Thanks,
Matt
 
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Old 12-21-16, 03:55 AM
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Where are you measuring the voltage? At the bulb socket/terminals? If you are using a non contact device, switch to an analog multimeter to make sure you have voltage. Use the hot wire and the neutral. It sounds most likely that you have a loose neutral at the fixture. If the switch does nothing to break the current, you probably have a "soft" switch and it needs to be replaced.
 
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Old 12-21-16, 09:09 AM
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And make sure you do the voltmeter test with a bulb in the socket....
 
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Old 12-24-16, 07:27 PM
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Thanks all for the feedback. Checking the voltage with the bulb in place was not possible, but I was able to connect it through jumper wires and the voltage dropped to zero with the bulb in the path. Current was also zero.

The issue ended up being the Harbor Breeze remote receiver module. It set a voltage at the bulb terminals, but was not able to drive the 150W load (though it was rated for 300W, so probably it worked at some point in the past). Removing the remote module and connecting the bulb across hot and neutral lit it up, so should be an easy replacement.

Thanks,
Matt
 
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Old 12-24-16, 08:06 PM
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The lamp is in series with the dimmer module. In other words the bulb is required for the light dimmer to work. This is one reason why LED bulbs are not recommended for use in a ceiling fan.
 
 

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