On Fri, 23 Nov 2012 14:45:00 -0500, wrote:

On Fri, 23 Nov 2012 09:06:27 -0800, wrote:

On Wed, 21 Nov 2012 10:50:53 -0800, Larry Jaques
wrote:

On Wed, 21 Nov 2012 09:14:00 -0800, wrote:

On Tue, 20 Nov 2012 09:57:42 -0800, Jim Stewart
wrote:

If you have fluorescent lights in your shop,
turn them off and see if the VFD still trips
out. Mine sometimes does with them on, doesn't
with them off.

I know it's clutching at straws, but it won't
cost anything to try it.

I just tried your suggestion. Didn't work. I'm sure the problem is the
voltage is too high. The VFD says the voltage is too high. The specs
for the VFD say the voltage in my shop is too high. But it was worth a
try. Of course, if it was the lights then I would have had to try to
figure out a way to filter out the noise. I understand transformers
better than filters.

Haven't you told your electric company of the problem and asked why
they are oversupplying your electricity? They might be able to fix
that for you with a call. Just cross your fingers.

http://tinyurl.com/a3pmclx PG&E's statement for reference
Unfortunately for me the voltage falls within the tolerance that the
power company follows. It's really too bad that all my machines and
all the controls have the ability to take the higher voltage. The only
problem is the VFD inside one machine. I was able to change
transformer taps and make adjustments to current sensing devices in
the machine but the VFD was built to accept voltages no higher than
240 volts.
Eric
How about a bucking coil? Grab a transformer with a 240 volt primary
and a 5 volt secondary, rated for your full device load. Connect the
secondary in series with the load - one way will add 5 volts, the
other will subtract 5 volts (buck boost). Run the primary off a Variac
and you can adjust the amount of buck/boost you require. Dead simple,
compact, and cheap. You don't need a transformer with a secondary
capable of handling 240 volts at full load.
I'm getting 3 buck/boost xmfrs Monday courtesy of Paul Drahn.
Eric