Low Voltage MR16 Hum
Hello all- I have a few fixtures (all recessed low voltage halogen MR16 bulb) that are humming. I know the ones with cheap transformers are susceptible to hum when dimmed, but mine seem to do it under full intensity. The dimmers are Lutron Maestro, I don’t know what the fixtures are but its safe to…
Hello all-
I have a few fixtures (all recessed low voltage halogen MR16 bulb) that are humming.
I know the ones with cheap transformers are susceptible to hum when dimmed, but mine seem to do it under full intensity. The dimmers are Lutron Maestro, I don’t know what the fixtures are but its safe to say they are not super cheap.
Is this a bad transformer in one of the housings or can I change the bulb type? Someone told me there are different types of bulbs. Any ideas?
Thank you
sorry to hear that you are having trouble with your LV lighting.
I am a lighting designer and know what you are saying.
As some posters have mentioned, there are two places to check, the Lamp and the transformer.
If all the fixtures in the house are truly the same model, then I suspect the lamps might be different. Just because the lamps are same wattage, different beam spreads and different companies have different filament designs. If you were to dim a tublar lamp (like in picture lamp, showcase or music stand light) you can actually see the filament shake or wave… you can actually create a standing wave inside the lamp. Usually MR16’s don’t have this problem because the filaments are short, BUT the “line voltage” MR16’s are LONG because they are designed for 120 Volts not 12v. However as above, each MR16 has its own filament design (horizontal/vertical/coiled etc.) and they may be causing the problem.
As for transformers humming, magnetic transformers are the worst offenders, however it is my thinking that if you have a transformer in each fixture, then chances are they could be electronic, in which case you shouldn’t have any hum as they operate in the thousands of HZ. (not 60hz).
And in regards to Dimmer and Load matching, yes you have to be careful here, THere are both ELV (Electronic Low Voltage) and MLV (Magnetic Low Voltage) dimmers. If you mis-match them, you can cause Electronic Transformers to make noise and fail pre-maturely over time.
So if you find that the lamps and the fixtures are identical between those that make noise and those that don’t, I figure you can try one of the following:
1> easy, try a different lamp
2> Add a “Choke” to the circuit, but the choke will make the noise, so it should be located in a place that won’t be bothered by that.
3> Swap out the Magnetic transformers inside the fixtures with electronic and change the dimmer to a matching ELV version.
3 may not be as easy as 1, but it should solve the problem for good.
As for phase testing, or good neutrals, in my experience, this has nothing to do with the problem. It is either filament sing or transformer buzz.
If you could post what happens, I’d appreciate the info
Thank you everyone so much.
I will check the easiest thing first, the bulbs. Then I’ll look into the phase tester.
These mr16 are definitely not the line voltage, my plugs are the low voltage type.
Good to know these should not buzz.
Recessed mr16 fixtures come as line voltage or low voltage. For the difference check a website like http://www.elcolighting.com
Yes, there are a lot of different bulbs and there is such a thing as “improper lamping.”
As far as dimmers go, they are rated for wattage, such as 600W or 2000W – for how many watts they are managing.
Verify your make and model and go from there.
(None of the recessed fixtures my electricians have installed have ever buzzed…)
There’s also a relatively cheap ($12?) phase tester you can buy at Lowe’s or HD – just touch the receptacles to get a reading.
I could swear that you need different dimmers for LV fixtures…
Short of installing chokes on the dimmers themselves, your best bet is to verify that the neutral is home run back to the breaker box and not bonded with ground anywhere along the way. If their ground and neutral path are in any way confused, dimmers and lo-voltage devices are unable to cope. They need a clean power structure and if they don’t get it, they often hum. Confounding your issue could be that one of the units might be incorrectly wired and it’s sending that noise down the neutral/ground to the other units which are responding sympathetically. IF that’s the case, you might try to wire past units one at a time to isolate the issue.
Yes, I meant transformers. Check they’re all in phase – esp. if you have 3-phase wiring.
mine buzzed, same model, when i did not use the correct bulbs.
It definitely only comes from a specific fixture, and only happens in 3 rooms. I have about 7 zones of this stuff. I don’t know if each fixture has its own transformer.
My contractor said the electrician says there’s nothing you can do, that some of them make noise or that its line noise. Somehow I don’t think this is true. It’s brand new stuff and made noise the first time I turned it on.
Would I be correct to insist that something is not right and needs to be addressed or do all these systems make some noise?