Re: [CAD_CAM_EDM_DRO] Re: capacitor

The calculation considers regeneration (and starting accel)
only -but--

I fully agree that more capacitance is a good thing with
less than perfect line power.

Out here in the backwoods we have our share of power problems. Most of my
stuff is 3 phase, but the cnc is not.
I have a UPS on the computer, but not the servo supply.
It can ride out a short power bump. It pretty much has to around here.

les

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.rabun.net/~leswatts/shop.html

----- Original Message -----
From: "Jon Elson" <elson@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, March 21, 2002 1:26 PM
Subject: Re: [CAD_CAM_EDM_DRO] Re: capacitor


> There's more to this! This calculation is for 120 charging pulses per
second.
> A recent thread on UPSs made me put the two together - this is why, when I
> had a power failure that left me completely in the dark for most of one
full
> second, my CNC system kept running right through it - without a UPS.
> The computer power supply had enough holdup capacity in it to keep the
> computer from losing power, the servo amps had enough capacity, too, and
> the VFD that runs the spindle also had enough capacity to ride through
> the outage without shutting down.
>
> THAT is why you need a LOT more than the very minimum capacitor bank
> from the calculation.