ancientbrass
Plastic
- Joined
- Apr 30, 2016
Good morning, colleagues!
I'm in the process of revamping the wiring on an old eastern European multi-purpose mill/lathe/shaper, while maintaining the original control hardware (because it's robust and convenient). I'm in a one-person owner-operator shop.
Situation is this: I have a VFD that can run 2- or 3-wire control, but there's no means to obtain FWD/REV/STOP(RESET) without control logic. (The FWD and REV controls are momentary NO, STOP is NC; VFD expects a fwd/rev switch and not separate FWD and REV run signals)
I am thinking to add a simple relay circuit to manage control, and then operate the VFD in 2-wire mode. FWD would trigger a holding relay, which triggers RUN on the VFD, and REV triggers RUN + a hold on REV.
My questions: (1) is this reasonable and (2) would low-impedance reed relays be a good choice for this job?
Edit: I would ideally like to supply voltage to the relays directly from the VFD control terminals, rather than using an external power supply.
I'm in the process of revamping the wiring on an old eastern European multi-purpose mill/lathe/shaper, while maintaining the original control hardware (because it's robust and convenient). I'm in a one-person owner-operator shop.
Situation is this: I have a VFD that can run 2- or 3-wire control, but there's no means to obtain FWD/REV/STOP(RESET) without control logic. (The FWD and REV controls are momentary NO, STOP is NC; VFD expects a fwd/rev switch and not separate FWD and REV run signals)
I am thinking to add a simple relay circuit to manage control, and then operate the VFD in 2-wire mode. FWD would trigger a holding relay, which triggers RUN on the VFD, and REV triggers RUN + a hold on REV.
My questions: (1) is this reasonable and (2) would low-impedance reed relays be a good choice for this job?
Edit: I would ideally like to supply voltage to the relays directly from the VFD control terminals, rather than using an external power supply.
