What's new
What's new

Recommendations for VFD able to use auxiliary switches for Bridgeport

Domodude17

Aluminum
Joined
Aug 14, 2017
I picked up a 1hp 3 phase Bridgeport with a J head. I'm planning on making a box with a FWD/REV switch, potentiometer, start/stop, and an E-Stop which ill mount in a convenient position. The VFD would be mounted separately elsewhere, so these are all remote switches. I simply don't know what to look for in a VFD to know if it's able to accept external inputs. Does anyone have ang suggestions on VFDs, or perhaps keywords or things I should be looking for?

A tangentially related question- I'll have the 240v power come into a main control box where the VFD is mounted. If I also run a neutral line into the box and use that line and one of the hot lines to get 120v power, will that affect the VFD at all? It would be to run an LED light, DRO, power feed, maybe a coolant pump if I ever get around to it.
 
Pretty much all VFD's have inputs for external run controls or remote controls, the first 2 or 3 inputs are often used for the run commands typically what are known as 2 wire control which work on sustained contact closure for forward reverse or 3 wire control which use momentary switches for the run commands and stop is a momentary break from a NC contact. There are several variations on how reverse is activated in 3 wire control. The VFD control inputs are low voltage (typically 12 or 24VDC) and low current. There are separate connections for a speed pot, typically these are linear 1-2W and anywhere from 1-5Kohm. Buy a decent potentiometer, the cheaper ones wear out quickly and can give erratic speeds. Some VFDs support a remote panel or the VFD control panel is removable and you need to buy an extension cable. I usually prefer just to have some remote switches. Entry level VFD's commonly used for these types of mills would be something like a Teco L510 or next level up would be the Teco E510, the latter supports an external breaking resistor. Teco manuals are easier to follow and they are decent entry level VFD's in my opinion. I would recommend a 240VAC input single phase 1 Hp VFD, although they do make 120VAC versions with 240VAC 3 phase output. A neutral is not connected to the VFD for a 240VAC input model, but if you want to pull off 120VAC for say a DRO and power drives then you may want to use a supplemental 15A breaker at the machine to feed the sockets. You need 4 wire cable power to the VFD control box for 240VAC VFD and 120 VAC sockets. I typically put two duplex sockets at the mill and run 120 VAC 15A power from each side of the 240 to each socket along with the neutral and ground.
 








 
Back
Top