Dimmers - wattage & buzzing


#1

I have two lighting tracks that are connected to a dimmer switch. These are Juno tracks with 39W halogen floods in them. I get occasional buzzing sounds from the tracks/bulbs. I have a GE Smart Dimmer controlling them (I’d get occasional buzzing before putting in the smart dimmer, seems more frequently with the GE dimmer). The dimmer is in a triple gang box which according to the GE instructions, lowers the dimmer rating to 400W. Would that contribute to the problem and would a different brand of dimmer solve this? Cooper RF9540 is rated to 600W in a triple gang box and Leviton is 650W, so they’d have more headroom, assuming that was part of the problem. Anyone have similar experiences or recommendations?


(ActionTiles.com co-founder Terry @ActionTiles; GitHub: @cosmicpuppy) #2

I’m no expert, but I’m interested in the Topic.

From the Wattage … I presume these are 120v bulbs (i.e., not low voltage 12v with a transformer)? Low voltage lights can work with a regular dimmer, but are more likely to flicker / buzz … so I’m asking :wink:.


#3

Yes, I should have been more clear, these are 120V bulbs.


(ActionTiles.com co-founder Terry @ActionTiles; GitHub: @cosmicpuppy) #4

The experience and research I’ve done is that buzzing is much more likely with low voltage than 120v, and that buzzing is sometimes a factor of the bulb, not only the dimmer.

I am running three 120v 20W halogens (on a single track), on a cheap Remotec (discontinued model) plug-in Z-Wave dimmer, and have neither flicker nor buzz at any dim level.


#5

Thanks, I’ve swapped out bulbs to see if it fixes it, and haven’t had much luck. From my Googling, it seems like a lot of the buzz can be caused by the dimmer, particularly if there’s too much load on it. I hadn’t realized the GE dimmer lost so much load capacity in a triple gang box (the docs say it goes down to 400W max load, but I don’t know if that’s just them being conservative). Hoping to get a sense of which dimmers are worth trying out to solve this.


#6

This might be of interest. Buzzing can occur with either too high or too low a load.

What’s the exact model of switch and the total number of bulbs Controlled by it?

Also note that many switches have two different load ratings, one for incandescents and one for LEDs. For example many GE switch models are rated at 400 maximum for incandescents, but about 100 maximum for LEDs when the heat sink tabs are broken off. (Also note that it’s the breaking off of these tabs that reduces the max in a multigang box.)

I don’t know that much about halogen other than that they typically do work in a way similar to incandescents. @Navat604 or one of the other wiring experts could probably say more.


#7

There’s 10 halogen bulbs total - 4 bulbs on track 1 and 6 bulbs on track 2, both on the same circuit, controlled from a GE Z-Wave Smart Dimmer 12724. The bulbs are 3 Philips EcoVantage 39W, 4 Satco 39W, and 3 GE Edison 45W. That would put the load for the bulbs at 408W. So, I don’t think that the buzzing is due to underload, more likely overload. Buzzing can come from either track and is intermittent. I’ve take out the 3 45W GE bulbs to see if bringing the load down to 273W makes a difference. To further complicate things, I’d planned to extend one of the tracks so that each track would have 6 bulbs, for a total of 12 bulbs, which would take the total load up to 468W.


(ActionTiles.com co-founder Terry @ActionTiles; GitHub: @cosmicpuppy) #8

468W !!! :warning: :hotsprings:

Have you considered replacing the bulbs with dimmable LEDs? I know they tend to be a bit “colder” light, but a huge power savings (and that solves your load problem too).

We have about 12 garden lights (12v AC) and went from 600W to 100W. Since we run these for 6 hours a night, that’s a huge savings.


#9

LEDs might be an option but these are PAR38 bulbs in open-back lampholders hanging from tracks, not recessed cans, so really need to match the look of the standard bulbs or it will substantially change the overall appearance of the fixtures. Only manufacturer I’m aware of that makes a bulb that would be a suitable replacement is BGLighting. I’m going to order one of their bulbs to check it out.


(ActionTiles.com co-founder Terry @ActionTiles; GitHub: @cosmicpuppy) #10

Yup… the manufacturers really haven’t caught up with the new lightbulb technology (and laws?!).


#11

FWIW, taking the 3 45W bulbs out of the mix to lighten the load eliminated the buzzing. I guess I either need to do with less lights, find LED bulbs that are suitable replacements, or go with a higher rated dimmer.


#12

Updating this in case anyone ever ends up experiencing something similar and finds it via search. Original problem was filament buzz of halogen PAR30 flood bulbs (incorrectly identified as PAR38 earlier) on track lights due to over-loaded GE Z-Wave Smart Dimmer 12724, which has a relatively low load rating, especially when used in multi-gang box. Halogen bulbs on the track lights had a combined load of 468W, GE Dimmer maxes out at 400W when in multi-gang box. Switched to LED bulbs to reduce combined load (down to about 120W), tried out Hyperikon and Philips PAR30 flood bulbs. Both brands buzzed excessively with GE Dimmer. Tried out the Cooper RF9540 and the Leviton VRMX1-1LZ. Both brands of bulbs still buzzed, although much less. Cooper seemed slightly better that Leviton for LEDs. Ended up switching back to halogen bulbs but using the Leviton dimmer which can handle a max load of 650W in triple gang box (up to 1000W in single gang box), which is a higher load rating than the Cooper. Everything works fine now, no buzz, although no energy savings either. Unfortunately, all the rest of my switches are GEs. Moral of the story - when putting in smart switches, start with the dimmers and only progress on to replacing the rest once you’re sure the dimmer is working fine. FWIW, I think that part of the problem with the LEDs might be that there are much fewer good LED PAR bulb options. Hopefully if I ever revisit the LED choice, there will be other good choices.


(Bruce) #13

I’m stuck (for now) with a bunch of halogen bulbs, and many are on this Leviton dimmer or its little cousin DZMX1.

Incidentally, the difference between the two is that the VRMX1 does instant reporting via z-wave, and the DZMX1 does not. This matters if you need the physical switch to quickly interact with SmartThings. If you don’t have that need, the DZMX is fine.

I still have buzzing in one low-volt system attached to a Leviton dimmer. I’ve found that setting the light to 50% brightness almost eliminates the sound. I’m not sure, but I think it may be a weak transformer that is causing the buzzing.