fileophile
Plastic
- Joined
- Mar 16, 2019
I'm wiring up the VFC controls for a Bridgeport mill. I discovered a new old stock Furnas 3-pushbutton remote panel I'd love to use because it is small and fits nicely on the left side of the head. The 3 pushbuttons are labeled FOR, REV, and STOP. I wired it up per the TECO manual 3-wire system and it all works great -- except that the REV pushbutton is a momentary NO switch so when you press REV it does work to put the mill in reverse, but only if you are holding down that pushbutton. As soon as you release it the VFD decels and returns to FOR motion.
I know I can hack and slash the REV momentary NO switch inside the Furnas enclosure and replace it with a toggle switch. But I'm hoping there is a more elegant way. I have seen electronics that can turn the behavior of a NO momentary switch into the behavior of a latched 2-position switch. I think this capability very well might be already built in to the TECO L510 VFD. Does anyone know if it is?
I'm thinking along the lines of setting a VFD parameter so that the VFD monitors the S3 control circuit. Whenever it senses a momentary change (open to closed) to reverses the motor direction and keeps it reversed until it senses another open to closed state change.
Do I have to use a 2-position switch for FOR-REV or can a momentary switch be made to work?
I know I can hack and slash the REV momentary NO switch inside the Furnas enclosure and replace it with a toggle switch. But I'm hoping there is a more elegant way. I have seen electronics that can turn the behavior of a NO momentary switch into the behavior of a latched 2-position switch. I think this capability very well might be already built in to the TECO L510 VFD. Does anyone know if it is?
I'm thinking along the lines of setting a VFD parameter so that the VFD monitors the S3 control circuit. Whenever it senses a momentary change (open to closed) to reverses the motor direction and keeps it reversed until it senses another open to closed state change.
Do I have to use a 2-position switch for FOR-REV or can a momentary switch be made to work?