[desert_rw]

Hi;
This is my first post to this forum, I have come here searching for suggestions that will lead to a solution for my Milltronics Partner CNC mill. It looks like this is a great community for people with similar interests and skills.
Basically, I have an older (circa 1995) Milltronics “Partner” 3 axis CNC mill that I purchased after refurbishing about 5 years ago. I don’t use the mill a lot and it has run great, always doing a good, accurate job despite my learning curve and mistakes. One of the best features of my rebuilt system has been the absolutely quiet spindle bearings. However, the spindle drive system is now my basic problem.
Whenever I command the spindle to run (example: M3 S2500) it barely moves then the machine enters “E-stop” mode. When I look in the back electrical cabinet I see the Saftronics PC3 variable frequency inverter/drive displaying “Oc”- this indicates “Overcurrent”. The booklet for the inverter claims this is due to 180% of the rated current being drawn. This symptom started soon after I tried to do some rigid tapping thru some ¾ steel plate with a 5/8 tap- the machine did not have enough torque at the slow tapping speed to make it. Basically when I tried the big rigid tapping job the spindle shut down immediately when it reached max torque (current). But now it immediately and almost always goes to “overcurrent” mode when simply starting the spindle under no load at all! I’ve manually checked the spindle and bearings, they are very free turning.
I have jumpered around the “safety loop” at the inverter, the machine no longer enters “E-Stop” mode but the spindle still stops immediately and the Saftronics displays “Oc”- this proves the source of the “E Stop” is the Saftronics inverter. I have also taken the Saftronics PC3 inverter out of the machine (apparently originally made by Yaskawa) and disassembled it completely looking for burned current sensing resistor or anything else odd. Nothing was noted, I cleaned it and re-assembled, installed the wires, and the symptom is still identical (at least I didn’t screw anything up).

When I searched online for this inverter I found that it is no longer made or supported, but I also found that there are at least a dozen variations on this particular inverter from Saftronics (Yaskawa). I’d buy one of the similar inverters on Ebay but I also cannot confirm the ID/model of my inverter (I suspect the original model no was removed by Milltronics). It uses 208 VAC three phase input, and the following markings are inside the unit:
MEC-37AV-0 (on main PCB)
Lot no N4W0005-004-144 (on main PCB)
YPCT31143-1A (on main PCB)
Code no ETP608270 (on main PCB)
SN 129617 (on alum case)
Any suggestions for repair, schematics, replacement (at reasonable cost), etc would be much appreciated. I also don’t know if there is a programming parameter in either the inverter or Milltronics system that needs to be reset, I’ve looked at the programming gobbledygook from Saftronics and it does not make any sense yet.
Apparently there is also a Saftronics PC7 that was intended as a replacement for the PC3- but I’m not sure about the installation changes, programming, etc.
Any thoughts? Ideas? Parts? I would like to use this machine lots more!
Thanks in advance!

[bocko912]

My partner 1D VFD was replaced with a Yaskawa V1000. It works well the only problem that I have is that the spindle will not orient for my tool changer. Other than that no problems.

[jpawelk]

Try to remove the output wires (the 3 wires that goto the spindle motor) and then try and run your spindle. Of course the spindle will not come on due to the removal of the wires. If the drive still displays the OC, then the drive will need repair or replacement. If the alarm does not show, then there is a problem with your spindle motor.

[desert_rw]

JPAWelk;
Thanks for the suggestion- I will try it. I'm reasonably convinced that the motor is OK but you are right- it could be internally shorted and drawing too much current even though it turns freely. That would seem to be a pretty rare failure mode for high end 3 phase motors but still possible.
Thank you

[imsly2]

pmhupman,

This sounds like a lot like an issue I might have just experienced. Tried turning on the spindle, heard a, "pop" and the spindle braking resistor started smoking.
For some reason mine doesn't appear to be going into an over current condition, but it looks like it's sending too much current to the braking resistor.

What model VFD do you have?
How did you go about diagnosing it was this module that failed?

Is that a link to the actual replacement module and place you purchased it from?

Thanks!

[pmhupman]

pmhupman,

This sounds like a lot like an issue I might have just experienced. Tried turning on the spindle, heard a, "pop" and the spindle braking resistor started smoking.
For some reason mine doesn't appear to be going into an over current condition, but it looks like it's sending too much current to the braking resistor.

What model VFD do you have?
How did you go about diagnosing it was this module that failed?

Is that a link to the actual replacement module and place you purchased it from?

Thanks!

Sorry for the late response, but it seems you have already diagnosed the problem. The braking resistor should never be smoking hot unless the transistor controlling the brake is shorted.

I'm here today because my Safetronics VFD died again and I've gone to a new (Toshiba) VFD and am looking for advice in resolving an orient issue.

[imsly2]

Are you making a new thread? I'm interested in any information you come up with. I got a FUGI AF-300 VFD and I still can't changed tools because I haven't sorted how to do the orient. I also overload the regen circuit during some spindle stops because I haven't figured out how to use the ext

[sportybob]

Are you making a new thread? I'm interested in any information you come up with. I got a FUGI AF-300 VFD and I still can't changed tools because I haven't sorted how to do the orient. I also overload the regen circuit during some spindle stops because I haven't figured out how to use the ext

Two new reply's to a thread started in 09. both concerning orient problems.
It is difficult to say whether or not your drive supports the orient / "JOG" function. Check the drive manual for a "programmable out put for the JOG function. Call the mfg to be sure it has a functional JOG with out an additional board.
Some drives require an additional "orient" board to accomplish this.Like the people using the Yaskawa V1000 drive have found out most "sales guys" don't know the difference between a "spindle" inverter and one that runs a conveyor.

You need a drive with at least 2 programmable outputs and several programmable inputs.

I sell and use a drive that works GREAT.

NOTE: If running on 1 phase power the drive should be rated for double the motor HP rating to get full HP out.


PM me for more info.

lets start a new thread for this.

sportybob

[shaffin]

Hello,

I am not sure if this helps but I would like to share my experience with my Milltronics Partner 1 Series H that I just bought used. The PC-3 was dead on it so I had to go through the experience of replacing it with the help of Milltronics of course. This is a summary of my ordeal:

- The techs at Milltronics were very helpful as they mentioned that a direct replacement for my PC-3 was the Yaskawa F7 at this time! So I was able to score a used drive on eBay and settled for the model CIMR-F7U23P7. The tech at Milltronics dont recommend a model but just the drive F7! I had to dig up the model by referencing my motor specs to what drive would be able to handle it, in my case I have a 7HP, 230v, 3Ph motor drawing 19.0A, and CIMR-F7U23P7 was able to handle 19.0A and 230v, 3Ph!

- The Milltronics tech also sent me an instruction manual of the parameters to set and how to configure the F7 drive for my Partner 1, and was impressed as it had a step-by-step method on configuring and setting up the drive (including wiring it). It also addressed the start-up and auto-tuning method that the F7 supported!

I am happy to say that from what I can tell I have been able to replace the PC-3 with the F7, run the spindle (in MDI mode), orient the spindle and perform a tool-change successfully. I am happy to share the instruction manual for those who do want to replace their PC-3 for the F7 drive if you want to PM me you email.

Thanks for all the help this community provides!

Sam.

[sportybob]

Hi Shaffin, , Sorry for the late response.
You have experienced the reason that Milltronics is one of THE best companies to work with. Who else is going to take a second owner and make him feel like a KING?
Even I am surprised that they sent you the "how to" As they sell the replacement f7 drive and would normally pass you of to parts. ( you silver tonged devil, you :;-) )

sportybob

[shaffin]

I totally agree sportybob, I am sold to the Milltronic brand!

[sportybob]

Are you making a new thread? I'm interested in any information you come up with. I got a FUGI AF-300 VFD and I still can't changed tools because I haven't sorted how to do the orient. I also overload the regen circuit during some spindle stops because I haven't figured out how to use the ext

Here is what I pulled from an on line manual. * (see my side notes)

AF-300Mini is a trademark of GE Fuji Drives USA, Inc.

During jogging, the jogging frequency (C20) and acceleration/deceleration time for jogging (H54) will apply. They are
exclusively prepared for jogging and required to be set up individually.
C codes: Control Functions of Frequency
C20 0.00 to 400.00Hz 0.01 Hz Y 0.00 *( usually set to about 3.0 Hz)

H codes: High Performance Functions
H54 ACC/DEC time (Jogging
operation) 0.00 to 3600s 0.01 s Y 6.00

E codes: Extension Terminal
E01 X1 terminal function (Select)
X2 terminal function
X3 terminal function
Selects from the following items by code.
0_(1000)Multistep freq. selection (0 to 7 stage)_SS1_
1_(1001)Multistep freq. selection (0 to 7 stage)_SS2_
2_(1002)Multistep freq. selection (0 to 7 stage)_SS4_
4_(1004)ACC/DEC time selection (2 stages) _RT1_
6_(1006)3-wire operation stop command_HLD_
7_(1007)Coast-to-stop command_BX_
8_(1008)Alarm reset_RST_
9_(1009)Trip command (External fault)_THR_
10_(1010)Jogging operation_JOG_ * ( jog / creep mode )
11_(1011)Freq. set 2 / Freq. set 1_Hz2/Hz1_
19_(1019)Write enable for Keypad (Data changeable)
_WE-KP_
20_(1020)PID control cancel_Hz/PID_
21_(1021)Normal/Inverse mode changeover_IVS_


sportybob

[sportybob]

Sorry for the late response, but it seems you have already diagnosed the problem. The braking resistor should never be smoking hot unless the transistor controlling the brake is shorted.

I'm here today because my Safetronics VFD died again and I've gone to a new (Toshiba) VFD and am looking for advice in resolving an orient issue.

What is the model # of your Toshiba drive???

see response to Imsly2, similar problem I suspect, but with out the model # I have no way to look at "YOUR" drive parameter listing.


sportybob

Bob M

[imsly2]

Here is what I pulled from an on line manual. * (see my side notes)

AF-300Mini is a trademark of GE Fuji Drives USA, Inc.

During jogging, the jogging frequency (C20) and acceleration/deceleration time for jogging (H54) will apply. They are
exclusively prepared for jogging and required to be set up individually.
C codes: Control Functions of Frequency
C20 0.00 to 400.00Hz 0.01 Hz Y 0.00 *( usually set to about 3.0 Hz)

sportybob

Thanks for the Help sportybob! My M19 orientate spindle is finally working and I haven't had it alarm out on me when stopping the spindle yet. Your comment about the Jog decel time gave me the idea to look at my F07 decel time. I increased it from 2.5 sec to 6 seconds and it stopped the regen overload alarm.

Now my tool change is working even better than before!! My tool carousel was drooping down a little so I loosened it up and raised it back up where it was more square to the spindle face, then reset the tool change Z position.

If anyone ever happens to pick up the same inverter as me. Or is anyone needs a reference for a factory set PC3 inverter, here's what I came up with.

Attachment 338572