[Will_0000]

Recently put in a Leadwell MCV 760AR with 4th axis. Got it powered up the other day and after clearing a few alarms it has been jogging around fine. Today it brought up the following:
S01 Servo Alarm 046
The mill powers up fine and the hydraulics come on with the interlocks disappearing on the control screen on the x,y & z axis. You can jog the bed around fine. After about 20 seconds the hydraulics drop out and the alarm code appears. The interlock sign for the 4 axis has never gone.

Any ideas as I don't have an alarm list and descriptions.

Many thanks

Will

[Rokkin]

Motor Overheat

[Will_0000]

Can't be as the alarm comes on from a cold start and the motors haven't been running. A sticking or faulty sensor? I am not sure how it is measured?

[Night Shift Wiz]

Can't be as the alarm comes on from a cold start and the motors haven't been running. A sticking or faulty sensor? I am not sure how it is measured?

Motor overheat is triggered from a thermal switch contact inside the motor. Jumper out the two wires and see if it clears the alarm.

[Will_0000]

Thanks, the thermal switch is reading normally closed as I believe it should. Also placed a jumper on the two contacts but the alarm is still there.

Any other thoughts?

Thanks

Will

[Night Shift Wiz]

If you jumpered the terminals on the servo board to eliminate any wiring problems, then it has to be the drive. Try swapping drive boards with another axis.

[Will_0000]

Not sure the best way of doing that as it is a single servo pack with all three drives in it.

With regards

Will

[Night Shift Wiz]

Is the 046 a controller alarm or the alarm that flashes on the servo drive? They are not always the same.

[Will_0000]

The display on the control say:
S03 Servo alarm 046

The drive also flashes 46 in-between two 56's

With regards

Will

[Night Shift Wiz]

Not familiar with your particular drive, but all the Mitsubishis I've worked on have similar alarm codes. 046 is motor overheat. 056 is problem in other drive.

You said you have a 4th axis? The drive you are having a problem with has 3 axis? Is there another drive for the 4th? Your first post said S01 alarm 046. Now it says S03 alarm 046. Is it moving between drives? Are you sure you jumpered the overheat terminals on the right drive? Maybe jumper all of them to be sure.

Some drives might have a parameter to disable/enable motor overheat sensor. I have no parameters for your drive. Did you try Mitsubishi Electric Automation Inc. - MEAU Home for manuals?

[Will_0000]

On my first post it was a typing error it has always been 03. The drive has always shown on F1 46 F2 56 F3 56 which is meant to indicate the X axis.

I have re jumper-ed all the cables at once and the S03 alarm has gone but been replaced by:

S01 Alarm 0032 which is supposed to be a Power module overcurrent.

I have since plugged the y and z cables back and the S03 has not come back so it seems to be on the x axis.

The 4 axis is plugged into it's own drive but I have tried disabling the 4 axis in the parameters but I still get the alarms so I don't think it is connected with it.

With the S03 alarm you could turn the machine on with no alarm shown, hydralics would kick in and it would function correclty for 20 seconds until the alarm registered, with the S01 alarm now it won't start the hydralics or function at all.

With regards

Will

[Night Shift Wiz]

So the alarm changed and also jumped from S3 to S1. I've had problems with multiple random alarms in the past where the cause was a faulty power supply control voltage (5, 12, 24 Volts). That might be something to check, both the NC and the servo/spindle PS. Many times it's a shorted sensor wire somewhere in the machine pulling the voltage down.

If you truly do have an overcurrent problem, first disconnect the UVW wires going to the motor. Check the motor for shorts to ground. If you still get the alarm with motor wires disconnected you probably have a shorted power transistor. Leave motor disconnected and measure resistance between UVW terminals and the + and - terminals of the inverter/Power Module bus. You should have at least a few hundred ohms or more. If not, replace transistor or the entire power module.

[Will_0000]

Thanks, I don't think it is a true overcurrent problem and that alarm is supposed to relate to a spindle error and not drive error.

I decided to prove out the motors as a starting point, placed the X axis on the Y axis, this generated no fault on the Y, so the motor must be good.

In doing so I striped back the connectors to inspect and found on the smaller plug (encoder) that there was a loose wire (yellow) There is a soldered pin with no wire on it.
This would slightly tie in with the fact that before we powered down the mill the bed was moved all the way forward to load the 4 axis and perhaps this wire was pulled.

The pin with the missing wire is pin E, I can't find a diagram of what this pin is supposed to do?

With regards

Will