"Karl Townsend" remove .NOT to reply wrote
in message nk.net...


I'd first check the no-load power consumption of the idler. If it's 7
amps at near 0 power factor, it doesn't cost much to run. Just
watch the electric meter for a little while with the idler being the
only load running. That (and a bit of calculation) will tell you
cost per hour of the idler's overhead.

I get 15 cents per hour(7amp*220Volt*$0.10/KwHr), or about $54 per month,
or $270 per season as my estimate. I've got no way to check power factor.
Just watching the meter, you can see it turns way more than the load from
all the lights being on in the barn.(1200 watts total). If the VFD has
virtually 0 power use at no load, there is enough savings to install it
here.


My problem with VFD's is that they're so danged complicated. There
are a buncha settings to get right. Maybe some of them have
"default" values you can invoke if all you want is 3 phase 60 Hz.

I've got VFDs on the mill and lathe. They both ran right outa the box. I
agree there's a ton of parameters. Most all of them will run just fine at
defaults.


To answer another fellow's question, we pack apples between each customer
visit all day long. We'd be turning it on/off fifty times a day to shut it
off when not running. Not practical. We turn on the lights and phase
converter when we open the door in the morning, and off when we lock up.

Karl

Karl

Your estimate of the idler's power draw at no load indicates that the
idler might be consuming about 2 HP. How big is the idler?

Jerry