[igrau]

Hi,

I did what I should not have and did 3 upgrades (spindle motor quick disconnect to prep for rapid turn, the smart cool and the power meter) at the the same time on my series 3, very shortly (say about 45 seconds over two cycles) after powering up the spindle at 250RPMs with no load it died. - lesson learned one upgrade at a time.

Smart cool works, every thing works, except spindle.
It spun for about 15 second the night I installed it and it was in the right direction sounded right so I called it and went to bed happy, next morning I wanted to verify the speed of the spindle and while getting the optical revolution counter ready the spindle just stopped, tried e-stop, reset, power cycle nothing brought it back

1. Spindle door switch is making good contact past the trip point as that can prevent the VFD from coming on.
2. Spindle lockout key works, have used it to clear the codes and it was not moved when this started.
3. Double checked all my wiring at motor electrical box and owed out every cable form VFD to motor and all looks good, no shorts between lines nor opens on lines. No poor connections with stringers.
4. C2 contractor (controls power to the VFD motor drive):
   
   1. Only engages if I disconnect the 3 motor lines from the VFD (400, 401, 402) but as expected gives an error code, it looks like tr r5 - suspect this is indicating open load, did not trace this as i expect an error.
   2. C2 contractor does not engage if I leave the 3 motor lines connected to the VFD , have finally gotten it to show me an error code and its 01.AC - which the manual describes as "VFD output instantaneous over current" infers a short to the motor or at the motor, not sure why its now showing a code all of a sudden, but while in the early debug I got nothing (hum, maybe early debug was misleading due to issues with 105/105A (spindle door open as the contact on the shorting bricks at the bottom of the cabinet are weak at best, wires come out easily and are a pain to put back in) anyway I got a code and its telling me ohm things out.
   
   
5. few more observations:
   
   1. Getting same result with path pilot as with manual controls which bypass the parallel printer cable/ribbon cable - so its not these cables. (also both reverse and forward do the same and I would suspect they are on different wires of these cables)
   2. FU01 and FU02 fuses are good
   3. By the way the motor is wired as a delta not a Y, did not change this.
   4. Also tried sticking in the PCNC 1100 programming key (when mill was fully off) in the VFD, powering it back on and testing spindle, but that did not help.

Here is the key help I would really appreciate - I measured around 3.2 - 3.3 ohms between any of the 3 lines at the VFD (wires 400, 401,402) after disconnecting them from the VFD but leaving them connected at the motor, does this sound right? Can anyone measure to confirm this is expected, I find it hard to believe that I killed the motor, but would really like to know if this matches readings for other PCNC 1100 spindles.

Will look for a VFD self test in the morning.

Any debug suggestions welcomed

Thanks

PS: Tormach support (the reason I went with PCNC 1100) called back and was great to talk with, gave many ideas and insight based on no error codes, but with a full time week day job, I only get to debug at times when Tormach support is closed, so hoping community can help me get this system back up - thanks

[mactec54]

igrau

I's this mod a disconnect between the motor from the VFD or just disconnects the starter/contactor for the VFD input power, so it turns off the power to VFD

Turning ON/OFF a VFD within a short time frame is not a good idea

[igrau]

@maxtec54

Its the motor from VFD, for easy swap of motors to say the rapid turn motor.

[mactec54]

@maxtec54

Its the motor from VFD, for easy swap of motors to say the rapid turn motor.

That a very bad idea, to have a switch between a VFD and motor, it is very easy to damage both motor or VFD by having a switch in this position

[wvines]

I measured the resistance on my series 2 machine. There was 4.3 to 4.6 ohms between each of the lines.

[tmarks11]

3.2 ohms is about what I would expect.

Check from each phase to ground and see if there is a short, with the motor plugged into the disconnect, measured from the three wires at the VFD (with them removed from the VFD terminals).

Grounding is far more likely to be the issue.

Does the C2 contactor not even try to cycle shut when you manually power the spindle from the front pane; keyswitch (can you here it "clunk")? Your machine control board shouldn't know that the VFD is seeing a shorted condition until the VFD powers on. This is a very strange scenario.

I would take four wires (phases + ground) and run them straight from the vfd to the junction box on the motor, and see if that works. That would isolate the problem as the section of wiring you messed with.

[tmarks11]

I measured the resistance on my series 2 machine. There was 4.3 to 4.6 ohms between each of the lines.

Was that with the wires disconnected from the VFD?

[wvines]

Was that with the wires disconnected from the VFD?

Yes. But it measures the same whether it's connected or not.

[igrau]

@maxtec54

Hum, its a Tormach kit to do this not my own design. It allows one to physically unplug one motor and plug in another - power must be off to do the change also requires changing the VFD programming stick. Curious, what makes this a bad idea?

[igrau]

@wvines - Thank you soooo much for taking the time to do this on your machines with VFD disconnected - THANKS

[igrau]

@tmarks11 - many many thanks for the comments

You are right the c2 contractor does engage both with key + closed door + manual start button or with key + closed door + path pilot. Yes like you said its the power to the VFD and I see the contractor sink in to make contact in both cases and in both the VFD quickly goes form 00 to 01.AC. My poor wording was related to when I got no codes as the unit was not powering up likely form poor 105 contact.

Measured ohms to ground on the 3 lines to the motor at the VFD end (disconnected from VFD) and get ~167-173k ohms to GND, is this also in line with your expectation. I noted it takes my ohm meter a while to settle down as if there is some capacitance but I don't see any other than parasitics of wires running next to each other.

Yup will try the jumper wire idea next but suspecting its not that as the measurements seem about right to me on the VFD end to the motor - please tell me if you thing I am wrong.

Thanks again, very much appreciate your time and ideas

Regard

[mactec54]

@maxtec54

Hum, its a Tormach kit to do this not my own design. It allows one to physically unplug one motor and plug in another - power must be off to do the change also requires changing the VFD programming stick. Curious, what makes this a bad idea?

If it where to be switched at the wrong time you will damage the VFD, there are special switches that can do this, but not at the small machine Hobby level

They should never have done this most VFD Drive Manufacturers do not recommend to do this as per snip attached

[wvines]

Weird problem. The motor resistances look OK. I would be suspicious of an intermittent problem with one of the control connections to the VFD, especially since you recently installed the load meter.

You may have done this already, but I would wiggle the wires and check the connections between the VFD and control board.

[igrau]

thanks for the info, unfortunately the design in the 1100 is essentially doing the don't do items on both sides

Granted the right side can't happen at the wrong time since one has to open the spindle cabinet and that opens the C2 relay (aka the one on the left in your pic) before the human can unplug the right side one - I know I have not unplugged the right side one when power on and I know all the connections on the right side to the motor were very tight as I double checked them last night.

Am wondering if the c2 opening while spindle was running may have killed/deprogrammed part of my VFD as I noticed a poor connection on 105/105A and it may have signaled the controller (via an open between 105 and 105A loop) that the cabinet was just opened and caused it to do a abrupt shutdown by opening C2. I think this could have happened when the spindle was running the last time (post the upgrade) and I was about to read out the RPMs when it died. But as I think about this its really is no different than what the estop does (well so I think)

Will look into this and the particular VFD that Tormach uses to see if this applies to this design too, but honestly I suspect it would have been a big issue by now if it does

thanks a lot for the tip @mactech54

[igrau]

@wvines, agreed its very odd, will recheck the control wires and remove the two for the power meter

Do you (or anyone) know if the VFD stick programs 100% of the VFD parameters or just a few high level parameters. Seems like programming is as simple as power down put stick into vid slot, power up, turn on c2 and that's it - or am i leaving out a critical step? I am asking as I am also wondering if the programming got corrupted and putting in the stick is fooling me into thinking i did a full reprogram.

Still need to go through the vfd manual to see if it has a self test that I can run. Or it give more clues to the error code. Plus try the direct wire to the motor.

thanks

[wvines]

I'm pretty sure the memory stick completely re-programs all of the VFD parameters.

BUT, there are a series of steps you have to do to get it to load from the stick. They are detailed starting on page 4 of the load meter installation instructions.

ETA: Actually, since you have a newer machine this probably isn't true anymore. The VFD on my machine is locked and requires a code (129) to change parameters. So.... nevermind. And good luck!

[nitewatchman]

If it where to be switched at the wrong time you will damage the VFD, there are special switches that can do this, but not at the small machine Hobby level

They should never have done this most VFD Drive Manufacturers do not recommend to do this as per snip attached

I don't think the situation you are describing exists here. If is like the High Speed Spindle Connection used on my machine, it is simply a plug connector that allows one motor to be disconnected from the drive and another reconnected in its place. The drive is reprogramed to match the exchanged motor using a dongle key that plugs into the front of the drive. There is no switch located downstream of the drive.

I use this on my 1100 for the 24K High Speed Spindle and it has worked quite well. You may see this in the last photo I posted on the fan shroud conversion kit.

The problem you are describing is very strange. Most VFD's will trip on an open leg or single phase event also, the drive sees a current imbalance and shuts down. If your connection is like mine, there is a terminal strip that connects the female socket to the VFD motor mains. You might disconnect these wires on both sides of the terminal block and lug then together. If it works then reattach the wires tot he terminal blocks until it either fails or continues to work. Only issue I had with mine was phasing. The HS Spindle could not be easily change so the connection box had to be first phased to get correct rotation of the HS Spindle and then the standard spindle rephrased to set its rotation.

gary

[nitewatchman]

@wvines, agreed its very odd, will recheck the control wires and remove the two for the power meter

Do you (or anyone) know if the VFD stick programs 100% of the VFD parameters or just a few high level parameters. Seems like programming is as simple as power down put stick into vid slot, power up, turn on c2 and that's it - or am i leaving out a critical step? I am asking as I am also wondering if the programming got corrupted and putting in the stick is fooling me into thinking i did a full reprogram.

Still need to go through the vfd manual to see if it has a self test that I can run. Or it give more clues to the error code. Plus try the direct wire to the motor.

thanks

Your last post jogged my memory and when I installed my kit it also tripped the drive when I first started it. I found that after the High Speed Motor was connected it would start, turn the spindle about 1/2 turn and trip. After checking all the wiring again I went back to the dongle pulled it and replugged it in. I then learned that on mine at least a fair amount of force was required to insert it to full depth in the slot. After it fully seated everything worked as expected.

[igrau]

@Wvines - Very interesting my load meter did not have those steps as the kit did not include a VFD programming stick, I happen to have the programming stick because I bought a rapid turn. Technically I should not need the stick for the load meter as my machine is a series 3 so I bought the cheaper 32096 kit.

Very oddly in the rapid turn manual https://www.tormach.com/uploads/1038...A_WEB-pdf.html pg 18 it simply shows the programming sequence I wrote below (they did it in a more elaborate from but the gist is there.) I don't see other VFD references in the manual with the key steps that your manual reference showed - thanks!!!

here is a picture of my load meter's page 4, its a 32096 - Load Meter (PCNC 1100 Series 3)

Attachment 345890

Anyway when I try the programing after the first M press I get
01 (flashing) 0.0
pressing m again
I get
01 (not flashing) code (flashing) <--- code being the actual 4 characters "code" not a number as expected.

Need to school up on the interface before I try and correct address this - may be since mine start from the tr code 01.ac

Thanks again super helpful to have the real programing sequence - am hopeful that a reprogram will make it work as a new $400 VFD will be painful

PS rechecked the VFD control wires, no difference
Removed the load meter, no difference
Supply to the VFD from C2 is at the expected 240AC between the 2 lines.
Not yet tried the direct wires (pain to get that back alan off the motor to reach its electrical box with my custom enclosure (pics will follow soon in a separate post)

Thanks again

[wvines]

Yeah, I just edited my post to tell you to ignore it. The newer Tormachs must ship with the VFD unlocked to support the HS spindle and RapidTurn.
Sorry about that!