Wiring Vevor VFD Control Panel in Remote Location

[Dave J]

I just went through this last year. After years of research, I came to the conclusion that it was better to have the E stop button cutting power to everything other than the VFDs, but the E stop turning them off via the VFD E stop curcuit, as said above.

The reason being that the VFDs can slow a spindle quicker than unpowering them, as they do stay powered after power off for a short time with their capacitors.

I'm in Australia, but evidently, regulations worldwide with a VFD are what stops the spindle the quickest with E stop is recommended.

Sent from my SM-A235F using Tapatalk

 

[stupoty]

Thanks for the comments-
to clarify the normal lathe startup and shutdown would be to use a start and stop button wired to the vfd control input terminals but the vfd is still always powered on. Only if the emergency stop is pushed whike motor is running would the motor still be turning when the vfd power turns off. In an emergency this could stop the motor quicker rather than going through the normal vfd deceleration steps.
Once the motor Is turned off with the normal stop button the emergency stop button can be used to turn off power to the vfd. I thought this might be better if not used for a long time and help to prevent damage from power surges due to lightning or other reasons.

as mksj says the VFD will almost certainly stop quicker than letting it coast to a stop. A drill or mill where there is less spinning mass might be different. I had to increase the default slow down speed on my lathe vfd as the chuck would unscrew from stopping so fast , which wasn't totally scary at all

Stu

 

[blueacre]

Thanks for all your comments and suggestions “mksj” A lot of great information and very helpful.

I am pretty comfortable with normal power and control wiring but this is my first project with a VFD. My first lathe was a Sirca 20 inch swing x approx. 7 ft center to center. Had a 7.5 HP 208 Volt 3 phase motor with 120V control circuit. I installed a 5 HP 240 Volt single phase with a 20% smaller pulley to reduce the top speed and HP requirements. I completely rewired the lathe – converted to 24VAC control power, new contactor with 24V coil, new current overload, all new push buttons and 24V pilot lights for power on, run and overload trip. The original pushbutton panel was near the bottom of the headstock base so I installed a second push button station on top of the headstock near the chuck. Also installed an emergency stop button near the tail stock since the bed was so long.

A bit of background on my shop setup. It is a 32 x 48 concrete block building with 14 ft ceilings and I added a 20x 32 extension on the one end. For the lathe and a lot of my other 240 volt equipment I installed 50 amp oven receptacles. I went that way rather than welding plugs because they are 3 wire plus ground so I have 120V available as well at each plug for control power. I have one 50 amp breaker that feeds a square D fused disconnect in my main shop that feeds a panel with 5 of the 50 amp oven receptacles for 2 x 250 amp AC/DC welders, a 180 amp Mig and a 60 amp plasma cutter plus 1 spare receptacle. From that panel I also feed power to another 50 amp Square D fused disconnect in the building addition which feeds 3 oven receptacles for 2 lathes and a spare.

Obviously with this setup I can only run 1 piece of equipment at a time since they are all fed from the same 50 amp breaker. I currently have the large 20 inch lathe mentioned above and a smaller one approx. 8 inch x 30 with 1 HP single phase motor. The one is larger than I need, and the other is too small a lot of my projects. I purchased the 15 inch Colchester lathe with the plan to sell the other 2 lathes and have 1 that will do most everything I need plus free up some shop space.

I want to go with my first VFD for this lathe mainly to try something new. I wont have a lot invested in it and I can always go to single phase motor phase converter in future if it doesn’t work out. I don’t think I will have any problem redoing the power and control wiring to convert the lathe to 240 Volt 3 phase. It is the VFD interface that is new to me. The Colchester lathe I purchased does not have a clutch so I think the softer start and ramp up with the VFD will be an advantage. It does have a hand brake that is integrated with the stop / start switch so I will have to reconfigure that so applying the hand brake will provide a stop input to the VFD.

Based on your comments I understand why can be preferable to keep power on the VFD and why it is better not to remove power from the VFD in an emergency stop. In my situation I typically use the lathes about 2 or 3 days per month. The building is heated but I don’t run the furnace when I am not there. It is well insulated including 2 inches of Styrofoam under the concrete floor so it never goes below 32 degrees. The VFD will be powered from the same circuit that feeds my 3 welders and plasma cutter. The one welder is an old heavy duty unit that I occasionally use for arc air. I am sure when I am welding at high amperage with the welder or using arc air there is a lot of spikes and “dirty power” on the circuit. With infrequent use and potential for spikes my preference is to disconnect power to the VFD when it won’t be used for an extended period. I could go with a disconnect switch, but I thought a contactor would have the advantage that it can be shut off remotely and if there is a power failure or “brown out” which we get occasionally in our rural area, the contactor will drop out and have to be reenergized manually. It would also be a second line of defense if there was a situation where the VFD fails to respond to a normal stop input.

Again thanks for all the suggestions and feedback.

 

[stupoty]

The VFD's should be fine with a little cold. I think it's mainly condensation that would be an issue.

I have had no issues witht he HY invertors I have , they live as close to being outside as you can get whilst still being in a room.

I did have a brand name one just stop working for no reason after being off for a few days then switched on. No hints at what went wrong , was only just outside of warranty, was about twice what the HY inverter I replaced it with cost.

Stu

 

[blueacre]

I decided to build a small local panel for starting, stopping and reversing my lathe. I see some guys using a 2 position selector switch with center off to turn the lathe on and off in either direction. My preference is to have a stop and start push button. I have attached a picture of the wiring diagram from my Vevor VFD and my proposed schematic for the local control panel at the lathe. I will have a 24VAC transformer in the main panel with the VFD. The local panel will have a 2 position selector switch to chose the direction. The start button will energize relay R1 and 1 normally open contact on R1 will close to maintain power to R1 until the stop button is pushed. Another normally open contact on R1 will close to complete the circuit from the selector switch back to the VFD for whichever direction the selector switch is set to. The VFD can also be stopped by turning the selector switch to the center off position.

If anyone sees any problems with this control arrangement please pass on your feedback.

 

[markba633csi]

I believe you can use the vfd internal 12 volt supply for the button functions
The internal relay could be used to light an indicator lamp
Some programming would be required

 

[Shotgun]

I used the ribbon cable to move the VFD controls up to a small panel that I could reach easily while operating; however, I still added button for on/off/reverse, and a potentiometer speed control. These had to be wired back to the box in parallel to extension cable.
My thinking is that those membrane buttons are the cheapest China can produce, and will be the limiting factor in the life of any VFD that makes it past the first two weeks. The panel is available to change settings and read the display, but not needed for routine operations.

 

[blueacre]

I believe you can use the vfd internal 12 volt supply for the button functions
The internal relay could be used to light an indicator lamp
Some programming would be required

thanks for the comment. I wasnt sure if I could do what you suggested. I already have quite a few 24V transformers, relays and pilot lights left over from other projects so its no extra cost and I dont have to worry about VFD programming changes.

 

[blueacre]

I used the ribbon cable to move the VFD controls up to a small panel that I could reach easily while operating; however, I still added button for on/off/reverse, and a potentiometer speed control. These had to be wired back to the box in parallel to extension cable.
My thinking is that those membrane buttons are the cheapest China can produce, and will be the limiting factor in the life of any VFD that makes it past the first two weeks. The panel is available to change settings and read the display, but not needed for routine operations.

Thanks for your comments. I originally was planning to relocate the VFD control panel to use as a local push button station at my lathe. Ultimately I decided not to do that - would have needed to buy a 10 foot ribbon cable and I already had most of the components to do a separate pushbutton station. I was also worried about how long the VFD membrane buttons would last like you said. My lathe has a good range of speeds so I dont have any plans to use the variable speed function very often so don't need to add a potentiometer.

 

[markba633csi]

I believe you will need to enable the remote functions in the menu- somewhat overstated to call it "programming"
but there are a couple things to change- you may also have to choose momentary or continuous switch contacts in the menu