Pm1340gt Lathe Basic Vfd Control Conversion Using The Stock Control Board And Switches

[mksj]

I would recommend starting a new post under the machine manufacturer, the system/wiring would be a bit different. I have built VFD systems for Acer lathes, but they have been complete replacement systems. If the contactors have been previously used, the contacts arc over and do a poor job of conducting low voltage signals. I do not favor use of contactors for switching VFD level signaling, this is just a simple patch to get a VFD machine up and running in my oppinion.

 

[Mr.Miz]

I would recommend starting a new post under the machine manufacturer, the system/wiring would be a bit different. I have built VFD systems for Acer lathes, but they have been complete replacement systems. If the contactors have been previously used, the contacts arc over and do a poor job of conducting low voltage signals. I do not favor use of contactors for switching VFD level signaling, this is just a simple patch to get a VFD machine up and running in my oppinion.

Thanks I'll start a new post. I've been uploading pictures into media as prep. I guess I'm having trouble getting over having all that front panel dead and having to mount the VFD somewhere and use it instead, that may all be "green horn" logic at this point but I'm just glad to have somewhere to start learning. Thanks.

 

[dpb]

For my own education, which is severely lacking in this area, what happens if you connect the 3-phase power from a VFD directly to the machine's electrical panel, as if you were connecting 3 phase from the building electrical service?

 

[mksj]

The problem is that a VFD output is suppose to be a direct connection to the motor, and you can potentially damage/toast the output section of the VFD by running it into the machine and using the contactors to switch power. In sensorless vector mode, you may get an error message when the motor is disconnected, and the VFD cannot brake the motor because it is now disconnected. You could potentially use the VFD in a fixed 60Hz and in a V/Hz mode, since you are powering the machines transformer, lights etc. they are designed for a specified frequency and voltage. Finally the output of the VFD is set to the specifications of the motor load, add other items and it will most likely fault or potentially damage the output. Any other power supply that has capacitors can also damage a VFD output. There are fixed output phase converters that are solid state or just use a RPC.

 

[dpb]

Makes sense, thank you.

 

[bench]

Installed the proximity senor using a Crydom D1210-B solid state relay. The relay is NC and the proximity sensor is wired to run NO. Works well. Repeatability is within 0.004mm.

 

[mksj]

Have had a number if inquiries for adding a joystick jog and 2 stage braking to basic PM 1340GT VFD basic wiring VFD conversions, so I have updated the information file and programming information.

 

[Djl338]

This is a great documentation for the 1340/vfd install. I’m about to do this, and only thing I’m unclear on is the 220v input. I see it going to the board opposite the transformer, then is the 220v input to the vfd a separate feed from the breaker or is it fed back to the vfd from the control board? I know this is not a new thread, but thanks in advance for the help and excellent write-up

 

[cbarmer]

Many individuals buy the PM1340GT lathe as a 3 phase machine with the intent to convert it over to a VFD system, the usual VFD that is used is the Hitachi WJ200-015SF. Unfortunately the conversion often requires a somewhat complex and costly conversion process to optimize many of the VFD functions. In many cases the machines may sit for many months if one is not familiar with how to do the conversion. I normally do these builds/conversions for other individuals, and have shared this information in this forum, but it is somewhat involved and very time consuming.

I normally do not recommend using contactors as relays for low level signals used to activate the VFD inputs, but if a machine is new and the contacts are not burnt, it is possible to rewire the stock control board (strip out the high voltage wiring and oveload relay), and use the contactors to switch the Forward/Reverse inputs contacts on the VFD. Once rewired, the machine will function the same as the stock machine would, and it will have the benefits of slower acceleration, faster deceleration and speed control. A VFD Jog can be incorporated by using a dual switch block Jog switch.

The stock 3 phase (or single phase control board with a 3 phase motor replacement) PM1340GT system control board and switches are reconfigured so that the contactors are used to activate the VFD control inputs for forward and reverse, the JOG button on the front panel activates the forward contactor which will work exactly as the non-VFD configuration, i.e. the motor will jog at the same speed as the forward command would. The conversion is best made by removing the control cable wires from the control system terminal and removing the control board from the machine. This should only be attempted by individuals that are comfortable with rewiring systems, and want to get the machine into an operational state. The attached documents provides the recommend procedures, although I have converted the stock PM1340GT control board to operate as such but have not done this as a complete conversion, so you can try it at your own risk. Please check all your connections, if you do not understand or cannot test the system, then have a system built for you and have an electrician work with the high voltage wiring. A basic overview of the changes are in the attached document.

Stock PM1340GT system control board
View attachment 132921

Modified PM1340GT control board with high voltage and motor connections removed. It retains the the stock 24VAC transformer and the controls work in the same manner as then non-modified board.
View attachment 132918

Full PM1340GT VFD Control Board System
View attachment 132925

Just got my 3 ph 1340gt today and also got the vfd
But I noticed my electric panel is slightly different
than the one in your pics. Will I have to deviate from the basic conversion as you describe it. I appreciate any advice and recommendations
Thanks

 

[mksj]

I would follow the directions previously posted, I believe the only difference is that they may have a cover interlock switch and they changed the wiring color. If you have any problems PM me and I can try to help.
Mark