Troubleshooting Overheat and X disconnect alarms

I have a Hardinge ST-220B that I am still struggling to get up and running for the first time. To start, I have a #1 alarm (overheat) on my main spindle amp. The thermostat is NO and I have continuity in the overheat circuit all the way back to the pins in the plug on the amp side. That leaves the amp itself being the culprit, right? Is there anything I can do to test / repair short of replacing the amp?

Second, while trying to sort out that problem, I came into the shop a couple of days ago to find I had a whole list of alarms on my X axis all related to the same thing:

416: X axis disconnect
300: X axis needs zrn
306: X axis battery zero
360: X axis pulse coder
400: X axis over load

And then today additionally:

Y axis needs zrn


My batteries are fresh and did not die. I have tested the continuity of the servo feedback cable and all wires have continuity with the following exception: there are two solid black wires in the motor side plug that and only one in the amp side plug. None of the black wires have continuity. Is it possible one black wire leaves the cable sheathing and go somewhere else that I can not see, and the other is broken somewhere along the way?

Unfortunately, I do not have a wiring diagram for this machine so I'm sure what wires do what but the fact that I also lost the Y axis zero today tells me this is again a drive problem as the X and Y share the same drive.

I'm at a loss for what to do next. Any advice or direction will be greatly appreciated.

I would swap the feedback cables for X and Y at the drive. Swap them while it's off. Then power up and see what alarms you get. Don't try to jog the machine. Your cables should be 114CBL and 62CBL. Report back here what you find. We're trying to see if the problem is with the encoder and cable or the drive.

I wouldn't worry too much about those black wires right now. They're probably just not used.

If you don't already have it, I can send you procedures for setting your zero positions on all the axes once you get this sorted.

Thanks, wmpy. I will do that when I'm in the shop next.

Update:
I made a little progress today but it raised more questions. Found where both the black wires went and they have continuity so my servo feedback cable is good or so it seems. After putting the cable back together, I'm no longer getting the X disconnect or over load alarms but still getting X and Y needs zero (expected) and X battery at zero alarms.

Its as if the drive isn't recognizing the battery but if the battery circuit was broken in the drive, I would think I was see an alarm for the Y axis battery too since they share the drive though.

Side note in case its relevant...
I also have a #1 alarm (motor overheat) on my main, and as of yesterday, now my sub spindle amps. I've tested the circuit for the main thermostat and it is closed as it should be yet I'm still getting the alarm. Haven't dug into the circuit on the sub yet.

I had the 01 alarm recently and found that the fan in the top of the drive was stopped. It wasn't actually overheating as the machine had only just been turned on. I tested with the drive next to it and as soon as I pulled the fan up and it disconnected it threw the 01 alarm. These are the fans on the top of the drive, not on the heatsink behind.

Jon, was that on a spindle or a servo amp? I've read that a #1 alarm indicates a bad drive fan on servo amps and a overheat of the spindle motor on spindle amps. If you resolved this alarm with a new drive fan on a spindle amp, I'll definitely look into that as well.

Looking at the fans on the drives is worth a shot. I had a machine where a small piece of junk fell into one of those drive fans after moving the machine. It prevented the fan from spinning and threw an alarm. While you're in there, make sure all the fans are spinning. It's good preventive maintenance. Just be careful sticking your head in the control cabinet with the power on.

If you have two drives with the same fans, just switch them and see. Can't hurt.

I want to think you guys for your help and give an update...

The issues with the X and Y axis appear to be resolved after dismantling the feedback cable for the X axis and cleaning it up. Still not sure why the Y was affected but nonetheless, those alarms are cleared aside from needing to zero the X and Y again. I will be doing that soon once I wrap my head around the X zero procedure. The Y zero procedure is pretty straight forward but the X zero procedure doesn't make a lot of sense to me. I'm sure I'm just missing something.

The #1 alarm on the main spindle amp...
So, I finally just paid a Fanuc tech to come out and I'm glad I did. I would have never figured the problem out on my own because the information he gave me, I haven't seen anywhere while researching and he stated that it isn't well known. You guys my know this but I wanted to share this info in case it helps you somewhere down the line. It turns out that getting digits displayed on the amp isn't always an alarm. Sometimes it just indicates an error, and although it means something isn't communicating properly, an error does not stop the machine from running the way an alarm does. This was the case with my amp. I had not tried running the spindle with a program (short sighted, I know). I had only used the "spindle orient" button to turn the spindle. It would orient but then give me an "01" on my drive. The tech said everything was working properly and he could not find any errors in communication. He said 99% of the time, if I need to orient the spindle, it will be done through programming and not using the orient button. Therefore, its unlikely the error will ever cause a problem in functionality.

Oh, and I did attempt to check the fan. Due to the age of my drives, the amp has to be removed from the machine to get to the fan. After disconnecting all wiring and mounting screws, I could not get the seal to break so the amp could be removed. Before forcing it, I called Fanuc to make sure I wasn't missing anything. Last thing I wanted to do was break something. That call led to me scheduling a tech cause they did not think it was the fan, nor had any other suggestions without running diagnostics.

Glad you got this sorted. Too bad you had to pay a tech to come out, though.

For the spindle orient pushbuttons, I only use those when tightening and loosening the collet nuts on the spindles. I don't know of any other use.

Let me know if you need help setting the X zero. I have a procedure for it. Unfortunately, this machine eats batteries more than any machine I've ever used, so I've done it a few times.

wmpy said:

For the spindle orient pushbuttons, I only use those when tightening and loosening the collet nuts on the spindles. I don't know of any other use.

Click to expand...

Be very careful doing that. Push the spindle off the encoder while tightening a nut, and it may do a full revolution trying to re-orient. If it does that while you're holding a wrench on the spindle, you're probably not going to have a great day.

TeachMePlease said:

Be very careful doing that. Push the spindle off the encoder while tightening a nut, and it may do a full revolution trying to re-orient. If it does that while you're holding a wrench on the spindle, you're probably not going to have a great day.

Click to expand...

I agree with this, but on this particular machine (Hardinge ST-220), pressing the spindle orient button performs a spindle orient and lock. The operator's manual instructs users to use this button when changing collets. But, yes, on any other machine, be very careful using spindle orient and then applying any torque on the spindle.