PM935 Hitachi WJ200 setup

[kb58]

Having finally gotten everything up and running, I thought that I'd give back to the group. The following is how to configure the Hitachi WJ200 VFD to control a PM935 mill with its 3-phase motor. The following assumes that a remote speed pot, forward switch to terminal 1, reverse switch to terminal 2, and Jog to Terminal 3:

Disclaimer: These settings worked for me, but these are not all the settings in the VFD, so it doesn't get around having to learn the unit.

Configure start/stop switch inputs, pg 4-16
A002 = 01
Set Fwd to terminal “1”, C001 = 00
Set Rev to terminal “2”, C002 = 01

Configure remote speed pot, pg 4-28
Pot on terminals “H”, “O”, and “L”
A001 = 01
A005 = 02 (confirm) (“AT” defaults to off, so selects pot by default)

DC braking, pg 3-26
A051 – 01 (enable during Stop)
A052 – brake applied below this frequency
A053 – Wait time before braking
A054 – Braking power, 0-100%
A055 – Braking duration, shorten this some?
A059 – Carrier frequency during braking

AC Braking, pg 3-71
Connect resistor to terminals “+” and “RB”
B095 Dynamic braking control, 01 = enable during Run
B096 Activation level, 360
B090 Dynamic braking usage, % per 100-seconds, 0.0-100.0%
B130 Overvoltage Suppression = 1 (enabled)

Jogging, pg 3-21, 4-19
Set terminal input, C003 = 06
Frequency, A038, try 4.0 Hz
Jog deceleration, a039 = 2 (DC braking and stop)

Notes:
· A038 must be > B082, or the value is zero
· Press Jog, then Fwd or Rev

Carrier frequency, B083, pg 3-69
B083, increase to decrease whine. 5 – 12KHz (motor runs warmer), set to 10
B089, automatic carrier freq reduction (to a minimum of B083), set to 01

Unattended Start, pg 4-25
Set terminal input, C004 = 13. Wire input “4” permanently high

Stop/Restart Mode, pg 3-72
B091, 00 = controlled deceleration
B088, 02 = resume motor drive at current spin-down speed (active frequency matching)

If you decide to try the "auto tune" feature:

Auto tune, pg 3-104, 3-108.
Auto tune selection, H001 = 02 (enabled with motor rotation)
Motor constant selection, H002 = 02 (use auto tuned data)
Motor capacity, H003 =2.2
Poles, H004 = 4

Notes:
· DC braking must be disabled (A051 = 0)
· Simple positioning P012 = 0

 

[mksj]

Nicely done. I have done a few VFD system builds for the 935/949 mills using the Hitachi WJ200. I use it with a latching relay system with momentary buttons, but one could also use 3 wire control which works well. I like to mount the run controls in a pod on the knee as opposed to overhead. I have not found the need to use DC injection, but as you have done an external braking resistor is required.

One thing to note is that the 935/949 use the same 2 speed constant Hp motor, which runs at either 4 pole or 2 pole. I wire the motors up on their 4 pole setting (1720 RPM) and run the VFD maximum frequency to 120 Hz which will give you the same RPM as 2 pole. You can also wire up a back gear sensor switch so that the mill rotation is always the same.

 

[kb58]

Looks like we have different motors. My PM935 has a 4-pole only motor.

 

[rogerl]

KB58:
Do you have any photos of the installation of the drive on the machine? I am curious on how and where you mounted it to the machine.

Thanks
Roger L

 

[kb58]

Yeah, I have pictures scattered all over this site,
https://www.hobby-machinist.com/attachments/img_20190202_192752-jpg.286929/

Which is from this thread: https://www.hobby-machinist.com/threads/another-pm935-base.76545/

 

[Karl_T]

.... You can also wire up a back gear sensor switch so that the mill rotation is always the same.

Tell me more. Which sensor and how did you mount it?

 

[rogerl]

What speed pot did you use and where did you mount it? I am assuming that you are using the existing on / off switch for forward and reverse.

Thanks
Roger L

 

[kb58]

All the electrical parts came from www.digikey.com. The pot, bottom-left, is 2K ohm (per the Hitachi manual) and just because I could, it's 5-turn. The Rev/Off/Fwd switch is wired into inputs 1 and 2. It would have been cheaper to use the existing factory Rev/Off/Fwd switch, but that's yet another control on the opposite side of the mill. Also, I've read that some high power switches (ironically) have trouble switching small "delicate" signals, like the logic level signals used to tell the VFD what to do. The "E-stop" button is simply in series with the Rev/Off/Fwd switch, which opens the circuit when pushed. Everything is in an aluminum case, mounting below the DRO. The red and green buttons were installed before realizing that one rotary switch for Rev/Off/Fwd could be used instead of separate Start, Stop, and Reverse buttons.

The very cool spindle light/tach sensor was not my idea; user "mksj" here came up with the design and I just copied it. Both the spindle light and the tachulator (also in the aluminum box) are powered by a cheap 12VDC, 2A wall adaptor.

An amusing aside is that when manually cutting out the rectangular hole for the LED display, I thought, "it would sure be nice to have a mill do this, but I can't until this is wired up."

 

[Stonebriar]

A very nice looking control box.

 

[rogerl]

I am setting up a WJ200 VFD on my PM-935 mill and I can not get to some of the parameters to set them. I can not see any of the H, P, or U function groups. I tried to do the initial setups in section 2 and I could not see parameter A082 . My display jumps from A045 to A085. I tried to set B012 and my display jumps from B011 to B037. Like I said above I can not see the H group to set H004. What am I doing wrong?
I was able to get the motor to run at 60 HZ forward and reverse from the selector switch. The motor had a rather loud whine when B083 was set to 2. I changed B083 to 10 and it is much quieter. If I call tech support at Precision Mathews will they be able to help with the drive questions I have?
Any information will be great.