RBM remove this wrote:
If turning on motors like vacuums or oil burners, well pumps, or 120 volt
heating devices like hair dryers, etc also causes this dimming,on circuits
other than the ones that these devices are connected to, I would have the
neutral connections to your service equipment checked

I have a microwave oven in the kitchen that is on a different circuit
than the espresso machine... I had my daughter start and stop the
microwave every second or so while I watched the lights in the
bathroom..

I get the same effect from the microwave powering on and off... very
very subtle "flicker", more like a very slight dimming and return to
normal brightness within in a few milliseconds.. the lights never
flicker to competely off then on.. just a very minimal dimming for a
few milliseconds. I really have to concentrate to see it. The lights
always return to full brighness once the appliance is running. Same
with the espresso machine.. If I switch the boiler heater to full on,
it makes the lights "dim" for that millisecond only at the start of the
heating element... the lights are at full brighness when full on.

In the case of the espresso machine, the power cycling in a regular
pattern once a second or so and makes this dimming more noticeable.

If not for the rythmic nature of the dimming, I'd never notice it's
ocurring.

My Garbage disposal also causes my lights in the house to dim slightly
when I first flick it on as well.. but more noticeably than the
espresso machine, and it's on it's own 20 amp circuit.. Lights dim
very slightly for a 1/2 a second then back to normal once the disposal
is running... I guess I never even noticed that either but I'm sure it
was happening all the time.

Wouldn't that be somewhat normal behavior, even for a 200 amp service?
I'm hoping so.. but now that I'm noticing it maybe I'm just getting
paranoid... if not for the pulsating effect of this appliance, I would
never have given any of it a second thought.

Maybe I don't even need to worry about it... like I said it's hardly
noticeable, and always returns back to normal once the appliance is
operating. Definately better than my old house with a 100 amp
service.. Am I off base here? Does anyone think I need to have this
checked by an electrician?

Tony B.