Suggestions on my vfd conversion

[DPittman]

N

This is my arrangement.....

View attachment 14293

The VFD key pad, display and POT aren't removable. Since it didn't support rev from the key pad I added that REV/OFF/FWD switch (from PA) as an external input. Once you tell the VFD to use external inputs it stops obeying the key pad run/stop/jog keys. The big paddle ESD switch interrupts the input power to the VFD. I'll probably change that arrangement such that it triggers the VFD's ESD function and wire in a on/off switch to interrupt the input power.

I'm not quite following you Craig.. if I understand you right, you have the big on/off switch before the vfd and with that off you don't have power to the vfd and the fan running all the time. Then the smaller yellow box switch appears to turn the motor fwd/off/Rev. Why would you need another on/off switch?

 

[YYCHM]

N

I'm not quite following you Craig.. if I understand you right, you have the big on/off switch before the vfd and with that off you don't have power to the vfd and the fan running all the time. Then the smaller yellow box switch appears to turn the motor fwd/off/Rev. Why would you need another on/off switch?

Killing the input power while the VFD is running (fwd or rev) can potentially damage it. Safer to trigger the VFD's ESD function. If I relegate the big switch to the VFD's low voltage external ESD function I still want a means of interrupting the input power when I'm not using it. In that case you're interrupting the input power when the VFD isn't running (fwd or rev) and it's safe to do so.

These things are kind of hard to get your head around at first.

 

[DPittman]

These things are kind of hard to get your head around at first

Man alive they are for a numb skull like me!
Isn't the panel fwd/Rev button overridden by the external yellow box switch. Is the vfd considered running even if the machine motor isn't on? Clearly I am missing something.

 

[YYCHM]

Man alive they are for a numb skull like me!
Isn't the panel fwd/Rev button overridden by the external yellow box switch. Is the vfd considered running even if the machine motor isn't on? Clearly I am missing something.

Yes my yellow fwd/stop/rev switch overrides the panel buttons, I programed the VFD to do that. The run/stop/jog buttons on the VFD panel no longer do anything, they are ignored. The VFD is ready to run once the display is active as in you have applied input power. You then instruct the VFD to run fwd, run rev, stop running. Think of it as run the logic to turn the motor clockwise, run the logic to turn the motor counter clockwise, and stop running logic.

 

[DPittman]

Right now my drill press and milling machine both have 1.5 hp single phase motors on them and both seem to have good power.

Do I need to increase my motor hp when converting to a vfd 3 phase system?

 

[YYCHM]

Right now my drill press and milling machine both have 1.5 hp single phase motors on them and both seem to have good power.

Do I need to increase my motor hp when converting to a vfd 3 phase system?

Large Bridgeports are only 1.5 HP motors. I have a 2 HP on my mill and thought I would need to go up but didn't. I'm not seeing any degradation. As I recollect @David_R8 went up 1/2 HP with his mill conversion.

 

[DavidR8]

Large Bridgeports are only 1.5 HP motors. I have a 2 HP on my mill and thought I would need to go up but didn't. I'm not seeing any degradation. As I recollect @David_R8 went up 1/2 HP with his mill conversion.

Yup I went up from 1 hp to 1.5 because I'd read that using the motor at lower frequencies reduced the available torque. So if total hp is increased then so is the available torque.

 

[YYCHM]

The other thing to remember is that if you really need that low RPM torque then belt down for those occasions. I'm loving my VFD conversion, I haven't changed a belt since.

 

[DPittman]

The other thing to remember is that if you really need that low RPM torque then belt down for those occasions. I'm loving my VFD conversion, I haven't changed a belt since.

Yes based on yours and @David_R8 experience I think I'm going to keep àt 1.5hp and have the ability to change belts for the super low or high speed stuff. I just wasn't sure how much of an issue torque loss with vfd drives was.

 

[DavidR8]

I have no problem driving a 1/2” drill at 20hz

 

[YYCHM]

I have no problem driving a 1/2” drill at 20hz

Me neither or a counter sink/chamfer down to 10hz. And..... I've actually gone up to 1" drilling with the VFD, mind you in steps.

BUT.... There are two kinds of VFDs. One is torque compensating the other? Vector is compensating I think.

 

[DPittman]

Potentiometers didn't come with an ounce of wiring instructions . Even though it's just 3 wires, I imagine it matters where they go. Anybody want to take a guess at what these characters on the back of the device mean?

 

[YYCHM]

Found this....

"Polarity usually does not matter for potentiometers. ... The potentiometer should be wired so that its two outer pins are connected to power (+5V) and ground, and its middle pin is connected to analog input "

So I'm guessing Z1 and Z2 are +5V and ground and the center terminal is the variable voltage analog output. The arrow symbol kind of makes sense.

 

[DPittman]

Found this....

"Polarity usually does not matter for potentiometers. ... The potentiometer should be wired so that its two outer pins are connected to power (+5V) and ground, and its middle pin is connected to analog input "

So I'm guessing Z1 and Z2 are +5V and ground and the center terminal is the variable voltage analog output. The arrow symbol kind of makes sense.

Good lord man you found the information I needed awful fast! Thank you. Now I feel stupid for asking

 

[combustable herbage]

I concur with YYCHN that wiring should get you going.
If you don't mind me asking where did you get your pot?
I have one in the basket at digi key letting its confidence build.

 

[DPittman]

I concur with YYCHN that wiring should get you going.
If you don't mind me asking where did you get your pot?
I have one in the basket at digi key letting its confidence build.

I bought it from Amazon. $13.89 a piece.

 

[John Conroy]

This is how I wired my mill.

 

[DavidR8]

I concur with YYCHN that wiring should get you going.
If you don't mind me asking where did you get your pot?
I have one in the basket at digi key letting its confidence build.

Here I thought that Digikey.ca was a Canadian company. Just bought some 4C shielded cable. Turns out its coming from MN.

 

[combustable herbage]

Here I thought that Digikey.ca was a Canadian company. Just bought some 4C shielded cable. Turns out its coming from MN.

I thought they had a warehouse in Canada too but from their website.

Digi-Key's headquarters and product distribution center is in Thief River Falls, Minnesota, USA. Regional support centers are in Israel, Germany, the Netherlands, China, Hong Kong, South Korea and Japan.

For me they are the best source for anything "not normal" in electronics, I have come into a few yaskawa servo controllers with a few motors and so I am playing with them have had some success in getting them to jog and play with parameters but I need the I/o connector and the pot and a 220V line in the basement to get more serious into doing something for my lathe.

 

[DPittman]

How is it going right now?

Well I'm wiring up remote switches on the machines right now and will likely post a picture "schematic" for others to check so I can avoid smoke when I put power to it. But I am also waiting for my motors to come which won't be to late next week.