ironhoarder
Cast Iron
- Joined
- Oct 9, 2005
- Location
- Waterford, VA USA
I have 2 milling machines. A Rockwell witha 3/4hp motor and a Bridgeport clone (enco) with a 1.5hp. I have a Hitachi L100 VFD rated for 1.5hp.
Money is very tight for projects like this. And, I am an electronics guy with lots of switches, relays, boxes, shielded wire, etc.
The 2 machines are withing 5' of each other.
So, here is what I'm thinking. I could build a box with relays that would switch between the 2 machines. It would switch both the 3 phase power as well as control lines for remote fwd/rev/stop buttons and speed pots.
My concern is the potential risk of damage to the VFD if it got switched while power was on to one of the machines. I suspect it would not be good for the VFD to have its load suddenly taken away, and then another load reapplied.
I could have big pilot lamps on the switchbox that would be powered by one of the legs, and a warning not to switch while the lights are on.
Or have some logic that watches the monitor signals on the vfd and will not throw the relay unless the time is right.
Boy this is getting complicated- maybe I better just look for another vfd for the 3/4hp motor...it may be a false economy to try to use one vfd for both- I dunno.
Money is very tight for projects like this. And, I am an electronics guy with lots of switches, relays, boxes, shielded wire, etc.
The 2 machines are withing 5' of each other.
So, here is what I'm thinking. I could build a box with relays that would switch between the 2 machines. It would switch both the 3 phase power as well as control lines for remote fwd/rev/stop buttons and speed pots.
My concern is the potential risk of damage to the VFD if it got switched while power was on to one of the machines. I suspect it would not be good for the VFD to have its load suddenly taken away, and then another load reapplied.
I could have big pilot lamps on the switchbox that would be powered by one of the legs, and a warning not to switch while the lights are on.
Or have some logic that watches the monitor signals on the vfd and will not throw the relay unless the time is right.
Boy this is getting complicated- maybe I better just look for another vfd for the 3/4hp motor...it may be a false economy to try to use one vfd for both- I dunno.