[4]

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

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#1
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
Stock PM1340GT Control Board .jpg

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.
Modified PM1340GT Control Board to switch VFD control inputs.jpg

Full PM1340GT VFD Control Board System
Full VFD Control Board System Conversion .jpg
 

Attachments

Last edited:
D

Deleted member 34477

Guest - Please Register!
Guest - Please Register!
#2
Nice write up Mark. Many will benefit from this and as always, very clean work.
 

arvidj

Active User
H-M Supporter - Gold Member ($25)
Joined
Oct 6, 2011
Messages
245
Likes
22
#3
Nice write up.

Maybe someone can provide a reference to information I've not been able to locate. I am wanting to put braking resistors on several WJ200 VFD's. It easy to determine the minimum resistance ... just look in the manual and see it is 35 or 50 ohms depending on the 2.2kw or the 1.5kw converter and 10% usage, respectively. What I have not been able to find documented is how to determine the wattage.

I understand the purpose of the resistor is to convert the braking energy to heat and wattage is an indication of the amount of heat\energy the resistor can safely dissipated without bad things happening. And I understand that "too much wattage" is not a technical problem but it does present other issues such as space and costs that do come into play.

Obviously the calculation would need to take into account what I was trying to stop. Just a spindle would not have nearly as much kinetic energy as the spindle with a large three jaw chuck and a large piece of metal in it. But setting that discussion aside for the moment, I've not been able to find any suggestions as to the wattage calculation.

Maybe I should just say the heck with it and get several of the fancy 500 watt shiny aluminum finned models from eBay at ~$40 each ... or just cheap out and get a 220 volt 1500 watt water heater element ... about 35 ohms ... at ~$9 a pop from the big box store.

Arvid
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#4
Hi Arvid,

The braking resistor is dependent on the WJ200 VFD model, voltage, phase and application. The attached file provides the specifics on the recommended braking resistors for the WJ200. The dissipation is application specific, so in cases where the VFD needs to hold a load in a static position, used with high frequency, etc. then the maximum wattage would be appropriate. In a lathe or mill, they brake for a few seconds and the dissipation is much less. I use a 500W 50 Ohm resistor on the WJ200-15SF for the lathe it doesn't get past slightly warm with repeated use and 1 second braking. You also need to think about mounting space and the lead voltage, which on a 220V VF, the braking resistor leads can go up to 400V. As far as resistance range, probably -10 to +50% of the specified value would be acceptable, so something like a 47 Ohm resistor should be fine for a 50 Ohm specification, and 75 Ohm for the high end value. The flat aluminum encased resistors will take up much less space, but need to be mounted to a metal surface to achieve their dissipation rating. In free air, a 500W resistor would be derated to something like 100-200W, and even then it would be fine in this application.

So for the WJ200-15SF I would suggest a 50 Ohm 250-500W resistor, the WJ200-22SF I would suggest a 35 Ohm 300-500W resistor. These are usually available on eBay for a little over $20, they are easy to install and take up much less space then the open air coil types.

Mark
 

Attachments

JimFouch

New Member
Registered
Joined
Dec 6, 2015
Messages
26
Likes
36
#5
I have a new PM-1340GT on order with Matt.

I'm planning on doing this upgrade. Will this work?
 

Attachments

GA Gyro

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Aug 12, 2014
Messages
930
Likes
206
#7

JimFouch

New Member
Registered
Joined
Dec 6, 2015
Messages
26
Likes
36
#8
I ended up ordering a 500W one from eBay. Now it will be a race to see if it gets here before my new 1340GT.....
 

arvidj

Active User
H-M Supporter - Gold Member ($25)
Joined
Oct 6, 2011
Messages
245
Likes
22
#9
Mark,

Thanks very much. That is 'the chart(s)' I have been looking for but have never been able to find!!

Arvid
 

JimFouch

New Member
Registered
Joined
Dec 6, 2015
Messages
26
Likes
36
#10
So with my PM1340GT on it's way to Matt in Pittsburgh, I'm starting to get some things in place so when I pick it up 2nd or 3rd week in August, I have some parts already to go on it.

Seeing this talk of upgrading the 3PH motor from stock I took a gamble and bought one of the E467 talked about on another thread. I think I got a pretty decent deal. It's NOS. Got it for $226 shipped. I think there are some suppliers selling them for like $385+shipping.

I know there are a ton of features that can be programmed on the WJ200 to control how it run/stop the motor. Is there a way for it to be programmed to stop the chuck in the same spot each time? I'm guessing no. There was some talk of an encoder on the motor shaft to control speed, but even if that were possible, you would never know how that relates to the chuck position because of all the different gear ratios.

I'm wondering if it would be possible to place a magnet on the chuck and have a microcontroller jog the motor until it has reached a hall-effect sensor and the desired stop point. This will allow the chuck key to always be accessible. I know it would be some extra electronics, but nothing I couldn't figure out.

I'm already planning on using the input from the hall-effect sensor for an RPM display I have planned.

I'm new to working with a lathe, but having to rotate the chuck to find the key most every time I stop seems to be an inefficiency that could be resolved.

I love hacking machines and making them better.....
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#11
I'm new to working with a lathe, but having to rotate the chuck to find the key most every time I stop seems to be an inefficiency that could be resolved.
Most chucks have either 2 or 3 key chuck pinions, so really not an issue. The chuck rotates easily or bump with the jog. Probably one of the most common requests I get for VFD control systems is for a Joystick Jog, so a very quick way to bump the chuck or turning to a specific spot. A proximity sensor stop used with a VFD will give you pretty much the same exact stopping/chuck position if threading and not disengaging the half nut.
http://www.hobby-machinist.com/thre...ding-with-a-proximity-stop.45977/#post-391715

The Marathon E467 should work very well and give a little better motor control, but the stock PM1340GT 3 phase motor is very good also. That is a very good price on the one your purchased. The E467 (and stock motor) should easily max out at 90Hz maintaining full Hp. Although Torque drops off above the motor's base frequency, the torque at the spindle would be the same as a 60Hz motor when you take into account the mechanical gearing ratio.
Mark
 

qualitymachinetools

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 22, 2013
Messages
347
Likes
374
#12
Great information as always mksj!!!!!!!
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#13
I just want to say thank you to Mark for making this information available. I have this exact machine PM-1340GT and WJ200 VFD and after reading trough the manual I feel much more comfortable tackling this project. I will post back and let you know how it's going.
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#14
I do have one question for Mark or anyone else who has performed this install. I am up to the point where I am installing the transformer wires onto the terminal block. I wanted to be sure of the orientation of those two wires " S, and R ." In Marks write up he doesn't specify and it's really tough to see the routing of those two in particular. Everything so up to this point has been a breeze. Hopefully the rest of this project will go the same way.

IMG_0883.JPG IMG_0884.JPG

edited to show images of cleaned up board ready to go back onto the machine.
 
Last edited:

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#15
There is no orientation to the S and R, since it is 220/240V which is split phase. The wire routing is not critical, I pulled the wires forward and connected them to terminals 1 and 2, so you would need to bring in power 240VAC to the board, You also need to ground the transformer (green terminal) and the control box the same as the stock system.
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#16
Thank you for the response Mark. I have left the stock transformer ground as is. Green wire from the green terminal to the side of the transformer on a stud. Do I need to run and additional wire from the green terminal to the ground on the control box?
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#17
Yes, the control board is phenolic so there is no ground connection from the transformer to the control box. You want to also ground the control box since there is 240VAC coming into it. This assures a good local ground, even though the motor is also grounded. All the grounds should go back to a single point (star ground), such as a metal back plane that the VFD would be mounted to, otherwise you can use a stud mounted where the power comes into the machine.
Star Ground.jpg
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#18
Mark you've been a great help and it is very much appreciated. I ran the additional ground from the transformer to the control box as you suggested. I think I've run into a problem though.

Like many others this machine sat in the shop for 3 to 4 months before I started this project yesterday. I'm having to deal with existing wiring that I'm not 100% sure is correct. I'm a complete newbie with this and want to be sure things are correct before turning the power back on. Please forgive me if my questions seem very basic.

Here is my problem (I think haha), I'm ready to bring power to the board but it looks like we only have one 208V 3 phase cable coming into the room.
IMG_0888.JPG
this is the existing wiring I spoke of previously. It looks like the electrician ran the power to the VFD, and them from the VFD to the control board. Here are the connections he made.
IMG_0887.JPG
From my very limited understanding, this seems incorrect. I believe I need to have two power sources, one for the control board and the other for the VFD. It looks like the area where I need to wire my motor into is being used by the power cord the electrician set up to go to the control board.

This is where I'm at now box and control board mounted to the lathe, and awaiting power to the terminal block.
IMG_0892.JPG

Please let me know if my assumption is correct/incorrect, and what further steps I need to take.
 

tmarks11

Active User
Registered
Joined
Aug 12, 2013
Messages
858
Likes
189
#19
Was your machine shipped to you as a 3 phase machine?

Most aren't, most of them operate off of 240V, single phase.
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#20
Was your machine shipped to you as a 3 phase machine?

Most aren't, most of them operate off of 240V, single phase.
Yes I believe it was Tim. I'm out of the shop for the night so can't go physically check right now. I am fairly certain it is a 3 phase motor. I'll reaffirm tomorrow.
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#21
The ground is wired fine, on the connections to the VFD it is difficult to see from the picture. If this is a single phase VFD (WJ200-015SF), then power (240VAC) comes in and connects to the input power L1 and N, the motor connections are U/T1, V/T2 and W/T3. The power transformer power would connect to L1 and N terminals, or the main power system switch. Nothing but the motor should be connected to the motor output terminals of the VFD. I am assuming you have a 3 phase motor, it makes no difference for the contactors/transformers if this was a single phase or 3 phase version.


WJ200 Single Phase Wiring.jpg
VFD Wiring Connections.jpg
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#22
I tried to get a clearer picture of my connections to the VFD, I can take more if need be.
IMG_0894.JPG
My VFD is version WJ200 - 022LF
IMG_0893.JPG
and thank you for the explanation and diagram that makes things clearer for me. I hoping that the model of my VFD won't change the details of this install to much. I apologize for not just giving all info upfront but, I've been kinda peicing this together as I went along. I am very greatful that you all are to to help out.
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#23
Just went and had a look at the motor specs it is a 3 phase and specs are as follows,

HP - 2 KW - 1.5
Volts - 220 Poles - 4
Hertz - 60 RPM - 1720
Amps - 6.6 Heat - 60 deg. C
Phase - 3 Date - 2016 01
Class - E Ser. - 2805
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#24
OK, so this is a 3 phase in VFD, the single phase version is the SF model. On some VFDs, the 3 phase model can be used on single phase, but usually there is a derating of about 0.6 x the nameplate kWA. So a 2.2kW/11A 3 phase would be derated to about 1.4kW/6.6A. So you should be able to use this VFD for the motor you have indicated. Sometimes a choke needs to be installed, but lets not go there for now. Start out by attaching the single phase input to the input terminals L1 and L3, and see if the VFD works. Sometimes you need to put a jumper from L3 to L2, but I would try to do this without the jumper first. Make sure the power is fused or on a breaker sized for single phase input. This works out to a 20 or 30A breaker, or for fusing ~30A fuse in the power lines going to L1 and L3 depending on the type and style. The VFD needs to be programmed for the motor nameplate information, along with the other parameters, out of the box it has different motor parameters.
 

Attachments

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#25
Hi Mark,

I' a little confused or not understanding the terminology but, I only have a 208V 3 phase power coming into the room. When you say attach one phase you mean one of the wires from the 3 phase connection?

I do know that the current wiring did power the VFD. I was able to turn it on and run through the parameters. I initially started by setting the B037 to " 00 " and started setting the parameters for my motor.

The electrician who installed the VFD has Black going to R/L1 Red going S/L2 and White going to T/L3. He left the ground Green wire floating (not connected to anything).

Thank you for bearing with me through this.
 

tmarks11

Active User
Registered
Joined
Aug 12, 2013
Messages
858
Likes
189
#26
You need to ground your motor and the VFD. The motor when running can induce a significant voltage level in the motor casing, which will shock you if you touch it. DAMHIKT..
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#27
Then it is fine as wired, I was unaware that you had 3 phase available. There would also be no derating for the VFD. As mentioned, the ground wire should be connected at both the VFD and the motor, it should not be floating. I normally use shielded motor cable, the shield is only grounded at the VFD end, this is separate to the ground wire. The transformer is only connected to between 2 phases, so something like L1 and L2.
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#28
I was able to make some progress this morning. I think I'm just about there. I cleaned up all the connection at the VFD, wired up the motor, and have my grounds wired as well.

Pics of latest wiring.

Wiring at VFD
IMG_0902.JPG 3 phase power into VFD Blk@R\L1, Red@S\L2, Wht.@T\L3. Also attached at R\L1 and S\L2 are my power wires going to the terminal control board opposite my transformer leads.
IMG_0903.JPG
Motors wires are matched accordingly
IMG_0901.JPG
Grounds are all wired back to the ground location at VFD. The 2 on the left are from the incoming 3 phase power, and from the motor ground. The one on the right is from the ground on the control board/transformer.
IMG_0899.JPG

I have not wired up any of the logic controls yet.

I am ready to flip the breaker back on but would like trained set of eyes to look and see if my wiring looks correct. I can then turn power back on and get to programming the VFD, and get the logic controls wired up. Thanks again to all that have come to help me out. Hope everyone enjoyed their weekend.
 

mksj

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 12, 2014
Messages
1,923
Likes
2,340
#29
Looks good, should be fine to power it up. You can program and auto tune the VFD to the motor via a computer via a USB cable, otherwise do it manually. When auto tuning, the belt needs to be removed from the motor.
 

chocadile

New Member
Registered
Joined
Aug 9, 2016
Messages
25
Likes
4
#30
Thank you Mark, I'll let you know how it goes.
 
[6]
[5] [7]
Top