ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
FPE in Germany
by NORCAL - 10/16/19 08:24 AM
Help with aging employee advice.
by Bill Addiss - 10/15/19 10:58 PM
Fuse blower plug?
by gfretwell - 10/13/19 03:23 PM
Power factor and transformer efficiency
by TeslaEdison - 10/13/19 04:05 AM
Permit Snafus...AHJs and Contractors Jump in
by HotLine1 - 10/10/19 07:35 AM
New in the Gallery:
FPE Breaker panel in germany
What is this for?
Who's Online Now
0 registered members (), 11 guests, and 12 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Humming Dimmer #75651 03/07/07 10:56 PM
Joined: Jun 2002
Posts: 206
H
Happi_Man Offline OP
Member
I have my theory but I am wondering what your first guess would be as to why a dimmer switch makes a humming sound (obviously when the light is on). How do you explain this to a homeowner?

Work Gear for Electricians and the Trades
Re: Humming Dimmer #75652 03/07/07 11:01 PM
Joined: Nov 2005
Posts: 186
HCE727 Offline
Member
Check out www.lutron.com


Hank
Re: Humming Dimmer #75653 03/07/07 11:51 PM
Joined: Nov 2005
Posts: 806
J
JoeTestingEngr Offline
Member
I think it is the standard answer: It doesn't know the words! The more the delay towards 90 degrees, the greater the harmonics / noise caused by the triac switching. This is in the audible spectrum. Snubber circuits are used in the output to reduce noise. I would expect that most of the noise you hear at the dimmer comes from the iron cored inductor of the snubber circuit. Think of the noise you hear coming from power transformers with some harmonics mixed in.
Joe

Re: Humming Dimmer #75654 03/08/07 01:59 PM
Joined: Mar 2005
Posts: 1,213
S
SteveFehr Offline
Member
Explain to them that there are coils of wire in the dimmer just like the coils in a speaker, and the fluctuating magnetic field makes it vibrate and hum a small bit.

It's not completely accurate, but should make them feel better.

Re: Humming Dimmer #75655 03/08/07 03:46 PM
Joined: Mar 2007
Posts: 404
noderaser Offline
Member
We also get hum from the lamp filaments, in our theatrical fixtures. Most newer lamps are designed to prevent this, but replacing all of our fixtures to work with newer lamp designs isn't cheap. Not sure if this is a problem with smaller bulbs (assuming 100 watt or less).

Re: Humming Dimmer #75656 03/08/07 08:41 PM
Joined: Dec 2004
Posts: 209
H
HLCbuild Offline
Member
All those things that Joe said...and cheap light bulbs. I used to have the same problem. The dimmer has a filter to keep the bulbs from humming. So now the dimmer hums. Upgrade your light bulbs.

Re: Humming Dimmer #75657 03/08/07 09:58 PM
Joined: Oct 2000
Posts: 2,720
Scott35 Offline
Broom Pusher and
Member
I was going to add what "noderaser" mentioned, but not needed now!

Looks like Lighting is more oriented towards the Entertainment Industry than previously expected, in that we have...

Singing Lamps and Humming Dimmers

Just couldn't resist that one! [Linked Image]

Scott35

edited to fix UBB coding blunder!

[This message has been edited by Scott35 (edited 03-08-2007).]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
RonKipperDatacom
RonKipperDatacom
Kansas City, KS
Posts: 30
Joined: January 2013
Show All Member Profiles 
Top Posters(30 Days)
sparky 10
Popular Topics(Views)
259,545 Are you busy
194,943 Re: Forum
184,371 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3