On 7/19/2010 7:37 AM, Meat Plow wrote:
On Sun, 18 Jul 2010 22:24:37 -0500, The Daring Dufas wrote:

The buzzing is caused by a bit of rust or believe or not an insect
caught in the armature of the contactor.

nods



Heard this sound many, many times. Doesn't take much rust on the
laminated core of the contactor or the plunger to make them hum.




There was a whole article in an EE magazine about converting AC
contactors to DC to prevent the buzzing which can cause overheating
of the contactor coil.

TDD