"Nate Nagel" wrote in message
The girlie yelled down from upstairs, "you know, when you turn that on,
the lights dim up here..." WTF? I was using them in a 20A kitchen
counter receptacle which has nothing else on the circuit. The 15A
lighting circuit for upstairs is completely separate (and may or may not
be on the same phase, I don't remember.) Is this an issue, and what could
cause it? I'm guessing poor neutral connection at the panel?

Granted I did buy a real honest-to-god Milwaukee Sawzall and a good
Milwaukee angle grinder, not some cheap lightweight crap, but I think both
are rated at 10A which I would assume a 12/2 branch circuit would handle
no problem.

Other factors come in play. Think of the electric supply as a water supply.
There is only so many watts coming into the house. When there is a surge at
one outlet, there will be a drop at another. Some tools take quite a bit of
power to start up, well beyond the 10A running load. Sort of the same as
when you are in the shower and the dishwasher suddenly fills.

At the same time you started up that grinder, the refrigerator, heater, TV,
lights, etc were using some of the available power so a surge was very
noticeable.