VFD Wiring

[EJay]

You will want to change your wiring in the control box on the back of the lathe, rather than the front switch panel. I have a schematic for the necessary changes for two different types of VFD on my blog. I think that your TECO uses the same wiring diagram as the AskPower listed on my blog.

If you have the manual for your lathe, it should have a wiring diagram, and you can see if it is the same as on my blog post. I'd be happy to review your schematic if you'd like.
Carl

Carl,

Thanks for the help. I took the front cover off to figure out the wiring for the switch panel. I downloaded your blog post. My wiring appears to be different. I don't have any contractors labeled "KM1" "KM2" or "kM3". So I'm a little lost following your blog. I currently have VFD wired directly to the motor. I attached a copy of my wiring diagram that came in my manual Along with some snapshots of the wiring in the back of the lathe. I'm not sure if I have "HY" series or the "ASK" series VFD. I bought a Teco L510-302-H1-U VFD. My FVD is a built in pontentiometer.

 

[EJay]

Carl,

Thanks for the help. I took the front cover off to figure out the wiring for the switch panel. I downloaded your blog post. My wiring appears to be different. I don't have any contractors labeled "KM1" "KM2" or "kM3". So I'm a little lost following your blog. I currently have VFD wired directly to the motor. I attached a copy of my wiring diagram that came in my manual Along with some snapshots of the wiring in the back of the lathe. I'm not sure if I have "HY" series or the "ASK" series VFD. I bought a Teco L510-302-H1-U VFD. My FVD is a built in pontentiometer.

 

[ignator]

That wiring diagram has a bit of confusion built in. It shows 3 different motor optional connections on the one diagram; the top diagram is single phase 220v, the next one down is single phase 110 volt, and the 3rd is 3 phase 220volt. I believe the 3 phase model has a coolant pump, as shown as M2 (motor 2).
Then there is the control and safety interlock at the bottom of the page. That is fed through a transformer for 24volt contactor coils. I become lost at the switches where FWD and REV are enabled. It appears these should be single pole double throw switches, but something is drawn wrong in my mind.
I also agree that using the motor contactor contacts is the way to control the VFD for FWD/REV.
There appears to be 3 limit switches used for interlock and FWD/REV control. L1, L2, L3. Then there are 2 push button PB1, PB2, that I think are start and stop related. The C contactor is the interlock to ensure there is no FWD/REV active with power on.

 

[lemelman]

I fitted a VFD to my 12x36 lathe a few years ago. I replaced the motor, used a Mitsubishi inverter, and wanted to retain all the original switching gear and just add a speed (frequency) control. I was somewhat dismayed when I opened the control box to find a mass of relays with wires everywhere. It looked horribly complicated.
It then occurred to me that all that complexity was to provide 2 major functions..
1. Provide a No Volt Release (NVR) system
2. Allow the Forward/Reverse switches to switch the motor on/off in the required direction.
Apart from the NVR, everything else can be done with the VFD.
It was obvious that the mains voltage went straight to a relay called KM1. A simple multi-meter set on AC Volts showed that terminals 3 & 5 of KM1 became live only after the lathe POWER START button was pushed, and stayed live until the mains lead was disconnected. This was the NVR, and all the other relays could be ignored.
The other important section in the control box was a long terminal strip. I removed the mains plug and, with the multi-meter set to resistance, determined what terminals were connected when the lathe was switched to forwards or backwards.
The diagram Diag-1 shows the important terminals on my lathe.
I could then wire KM1 terminals 3 & 5 straight to the VFD power input and connect the wires that used to go to terminals 7,7,13,5,5,4 to a new chocolate strip as shown in Diag-2.
I then made up a couple of 3-core cables to connect the chocolate strip to the VFD control terminals. These are all low voltage. I never used the inching control of the lathe so I removed the switch and replaced it with a speed ctl potentiometer for the VFD, and added a nice scale.
The VFD terminals in Diag-2 show those for my Mitsubishi; yours will probably be different, but will have the same function.
Everything on the lathe works as it did before, except I now have a speed control knob too.

 

[cds4byu]

Ejay,

I've been looking at your control box and your wiring diagram.

As is, your wiring diagram may or may not make lots of sense to me. Are there any other wiring-related pages in your manual (e.g. a component layout diagram)?

Let me ask you a couple of questions:

1. Does your lathe have an E-stop button?

2. Does your Start button have a light that turns on and stays on when you press it?

3. Can you run coolant without the power start light on?

Then I have a couple of questions about your photos of the control box

1. Can you take some photos of the lower right corner, preferably that show the numbers on the white rings on the wires?

2. Can you tell me where the wires that go out of the box in each of the wire ports?

Finally, you said you have a 111-310 lathe. I can't find any references to that model. I see a 111-3110 and a 111-3310. Can you confirm your model number?

I hope to get you some good answers about how to hook up the VFD.

Thansk,

Carl