Re: Best practice for mill VFD control wiring

My plans solidified a little bit. I will use the original START/STOP
to supply or kill power coming _INTO_ the VFD.

I will install an Allen Bradley 800T style lever switch with XA
switches, that has three positions, to provide FORWARD/OFF/REVERSE
functionality. The lever switch has an extra convenience of being
equivalent, on tactile level, to the direction of intended rotation
(turn to the right for clockwise, turn to left for counterclockwise).

In addition I will mount some speed control pot near the lever.

i

On 2009-08-24, RoyJ <spamless@xxxxxxxxxxxxx> wrote:
I agree that a big red 'OFF' button should kill everything, VFD included.

I tend to like all the controls in one spot with the panic controls on
the top with the regular controls lower on the same panel. No sense
having an operator have to think about if a situation is a big deal and
have to move to a different panel. Milliseconds matter at this point.

Ignoramus25401 wrote:
I am back from my RV trip. (which went very well)

This post is in regards to that Arboga EM825 mill that I am working
on. It is three phase and works well. This is a 1.1 HP, 3 phase
mill/drill with geared drive. It does not have and has never have a
reverse switch of any kind.

My plan is to convert it to single phase by means of adding a VFD, do
a nice job at that, and sell it to single phase people.

I use a Toshiba VF-A3 drive, the same one as what Pete C and Ivan
Vegvary have.

So far, I got to the point of having the drive mounted and I use panel
controls to run the mill. So now it does run great from single
phase. This is not the most convenient and not the safest option due
to where the drive is mounted (low height).

I would like feedback about the following plan:

* Mount drive out of the way to the right of the base.
* Use the original START/STOP buttons on the right side for START and
STOP control of VFD.
* Add a panel on the left side, composed of
o SPDT On-On switch to switch FORWARD and REVERSE
o Potentiometer to adjust mill speed from 0 to 80 Hz.
(the higher limit is the VFD setting).
* Program acceleration time to be 1 second and deceleration time to be
0.4 seconds.

Is that plan basically sufficient and does it constitute "best
practices"?

My own reasoning is that START/STOP is basically a safety function and
it would be good to retain it in its original design for legal
reasons.

i
.

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