Hi all,
I have a VFD that I am trying to setup on a lathe with momentary push buttons for Start, Stop and Jog and a selector Switch for Forward/Reverse. In the manual I found a wiring diagram but am not sure what type of relay to use, and were to attach the switch to appropriate terminals of relay/vfd. I believe the relays are normally numbered.
Relay MAY be already on the PCB. Giving it a "number" is the klew. See the physical layout section of the manual. If so, size of a (small) ice-cube. It is cheaper for the maker to include one on every PCB, even if never used, than to deal with the service calls about either confusion or damaged VFD.
If No Joy, you "tecnnically" need a 3PST. Three poles, single "throw", 24 V operating coil.
The + sign on the schematic indicates that should be a DC coil rating. Most times, AC or DC coil doesn't matter in these small units, so they may be listed AS "AC/DC".
It will usually be better, easier and probably cheaper, to use the "appropriate" side of a 3PDT or a 4PDT (double throw) for future flexibility.
Cheap enough stuff, and all over the place. The simplest of many players as to "contact form", if that should confuse your search, is explained here:
Understanding Switch Topologies - National Instruments
..but doesn't much matter in this application. It ain't the "hook switch" for a 1960's 4W E&M multi-line telephone set.
Look for a built-on
first, as you need a place to PUT the thing SAFELY and fasten it as well as wire to it if you have to furnish your own. Adhesives can work for that. The fastening. Not the wire.