What's that Lassie? You say that ATP* fell down the old
rec.crafts.metalworking mine and will die if we don't mount a rescue
by Mon, 5 Jan 2009 20:38:00 -0500:

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I was very surprised to see the unloaded current so high.

That's a pretty big motor, I would expect it to pull 10 amps just running.
Full load amps is close to 60.

I would too. But when the valve cycled, the load went to only 15A.


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As far as the demand charge, wouldn't even be 1% of our total load.
We have 21 big CNC machines. And in the summer, 10 big AC units on
the roof.
We have our own transformer, big as a small car, on a pad outside of
the power room.

A drop in the bucket compared to all that, but could still be a significant
yearly cost.

I agree. But I'm trying to get to an hourly cost. So when the owner
complains about the cost of having the air on for a few hours over the
weekend, I can counter with a realistic figure. And be able to 'show
my work' as well. He seems to think that since the motor runs
continuously, that 25hp of power is being used. So I want to have the
information about the loaded and unloaded current draw, and the duty
cycle when I'm using it. That way I can figure an hourly cost to run.

Thanks for all the help.

--

Dan H.