my dimmer switch noticeably buzzes.?

Question

the switch controls two outlet boxes to which i have a total of 300 watts of power being used. The place has older wiring with only a hot wire and neutral wire although i did connect a ground from switch to the back of the box. The buzzing changes in frequencey from noticable to very noticeable and happens whether
i use a 600w single pole dimmer switch or a 1100w single pole dimmer switch but does not happen if i use a standard on/off switch.

someone had mentioned a low voltage dimmer switch in the past, but when i went to purchase it the 'knowledgeable' workers said the safety would be questionable since the low voltage dimmer is rated for 300w and the switch controls 300w. Also, the 'knowledgeable' staff were seriously questioning whether a low voltage switch would solve the problem. Now, although electricians make up the staff at the store, it was an electrician at another store who told me i needed a low voltage switch. I guess I'm going to treat you as the tie-breaker. You are right, there are a number of other outlets and switches that run off the same fuse that the switch in question runs from. So, if possible, can you explain why a standard on/off switch produces no buzz while the dimmers do, and will i be o.k. going with 300w off of a low voltage switch?

Let me start by saying to all those that have provided feedback, thank you. Your responses have increased my knowledge about a subject matter that i am admittedly ignorant in......Here is some additional information as requested: Before posting here, the first thing i did was to go to a reputable electrical store. The staff there did not have an answer to my problem and did not feel that a low voltage switch would solve the problem. The said i could try it, but if it did not work i would not be able to return the $50 switch. The 600w and 1000w dimmer switches that i have already tried were made by Lutron. Both produced the same buzzing from the switch; a buzzing which changes in frequency as the slide is moved. The switch controls two outlet boxes that reside in the upper corners of a large bookcase. I installed two 'Hampton Bay' track lighting kits (designed to plug into an outlet): one for each outlet. Each track/outlet has three 50w track lights attached to it.

also, i don't know if this matters, but the switch runs off of a 20amp fuse. The same 20amp fuse covers everything in the kitchen (refridgerator, microwave, ceiling fixture) as well as the light fixture in the bathroom.

Answer 1

Add to the other advice -
1- With older wiring, I wouldn't be surprised that the wire is only size 14. (15 amp circuit maximum) [that is 1500 watts total].
2- Again, older wiring (perhaps cloth and rubber covered wire) it probably has a 15 Amp fuse at the end of the circuit.
3- Try to get an accurate load in every part of the circuit total receptacles with everything plugged in + lighting and see how close to the 1500 watt limit you really are.
4- The dimmers you mentioned should have been mounted in the switch box "as is". If any of the tabs "heat sinks" have been broken off or removed, (the aluminum frame around the front edge of the switch) to fit the box, these reduce the wattage max the switch is labeled for [called derating].
5- Shouldn't matter too much on the 1100w switch but the added load of everything else on the 300 one might cause chattering.
6- If I remember right, there are rotary dimmers, slider dimmers and dimmers with neon indicators in them.
I don't see how a low voltage dimmer will help since having a transformer in the circuit only separates the regular voltage from the lower one. Good Luck !

Answer 2

Dimmers operate by sending pulses of current to the lights you're controlling. The pulses occur at 120 times a second, the pulse length determines the brightness of the lamp. So two things can happen. The coils inside the dimmer, that prevent radio interference can sometime hum. And the pulses can actually make the filaments inside the bulb resonate and buzz or sing. The size of the dimmer makes no difference, neither does grounding.
Solution, well certain brands of dimmers are better than others. As are different models. I've had good luck with Cooper and Lutron. If you go to an actual electrical supply store, and explain your dilemma. They have the smarts to get things sorted out for you. Oh, switches are either on or off, they don't pulse, so no buzz. Hope this enlightens you. (Sorry couldn't resist)

Answer 3

I have a similar problem in my dining room. It buzzes when dim, fine when bright. I too have old wiring. MC cable i believe. Its 14 guage, which is problem #1 for you running a 20A breaker. #2, dimmers are not supposed to be hooked to receptacles, I have done it, but only in my house, not customers. You may be able to scrap the dimmer entirely and go with a switch with 2 or 3 positions. This way you have three light settings. They do have certain dimmers that arent supposed to hum or buzz. I want to say I have seen them at Lowes. I would ask a rep at an electrical supply store rather than a hardware store.

Answer 4

Unfortunately the circuit that your dimmer is wired to cannot handle the amount of wattage required for maintaining the light fixture. The circuit is most likely sharing other duties such as a few outlets, and a couple of ceiling fixtures.

You can purchase a low voltage dimmer switch. They are a little more expensive but worth it if you don't have the money to rewire your breakers. However, it is pretty dangerous not to ground your switch in the traditional way. Talk to your local hardware store electric specialist and tell him that you need the low voltage dimmer but you don't have a traditional ground wire for your wall outlet. They will help you ground the box the right way.

Hope this Helps!

Answer 5

I normally can't hear this buzz, but my wife can. Some people are very receptive to the 60 cycle buzz. This is usually more common in the less expensive dimmers. It is a vibration caused by the current going through the electronic components. I would suggest replacing the dimmer with a higher quality one. Most manufacturers make both high and lower quality products.

Answer 6

you didnt really say the outlets were for lighting yet everyone assumed it..........what are you using these outlets for??
if anything else that incandescent(filiment type bulbs) the dimmers wont work properly

Answer 7

complicated aspect. do a search onto a search engine. it can assist!