[jacof]

Good day
Can anybody help.
Got these errors on a lathe. DNG 720 .4 OR 5 COMES ON DEPENDING HOW FAST IT MOVES.
Already changed the servo drive , cable for encoder , cable for motor, encoder it self, swapped the plugs on the axis card and rechecked all the parameters.
This all happens with the motor shaft disconnected from the ballscrew. Hope there is some one that can help.!!!!!!!!!
THX

[ifixcnc]

720 4: an improper current alarm (HCAL)
5: excessive current alarm (OVC)
Check the motor leg to leg, should be low Ohms and balenced. And leg to ground, should show as an open on high Ohms. A megger is best for leg to ground.

[hub]

I have different servos & drives but I got a over current error (like you). It was a mechanical fault, one of my thrust bearings had died & jammed the machine.
Check if your mechanical components are fine & smooth running. The fault is in some of those I think.

[ifixcnc]

This all happens with the motor shaft disconnected from the ballscrew, I think that eliminates the mechanical parts.

[hub]

This all happens with the motor shaft disconnected from the ballscrew, I think that eliminates the mechanical parts.

Yes, you're correct, I missed that sorry.
Maybe its the motor then. If it has brushes, change to new ones. If not the windings might be damaged..

[jacof]

720 4: an improper current alarm (HCAL)
5: excessive current alarm (OVC)
Check the motor leg to leg, should be low Ohms and balenced. And leg to ground, should show as an open on high Ohms. A megger is best for leg to ground.

Thanx for your reply s.
Think I already used a megger.Will recheck and let you know.THX

[jacof]

This is a AC Servo motor , and the motor is disconnected from the ballscrew , so that eliminates the bearings/ mechanical.
Thx for the reply

[jacof]

This is a AC Servo motor , and the motor is disconnected from the ballscrew , so that eliminates the bearings/ mechanical.
Thx for the reply

Good day.
Re-megger the motor and cable. All o.k. Made new cables and run them to a working axis proving that my cables are o.k
Then ran them as is back to the axis giving fault.Same fault which means motor is faulty/ not compatible.
Supplier is sending another servo motor today.
Will keep you posted.
THX

[jacof]

720 4: an improper current alarm (HCAL)
5: excessive current alarm (OVC)
Check the motor leg to leg, should be low Ohms and balenced. And leg to ground, should show as an open on high Ohms. A megger is best for leg to ground.

Hi ifixcnc.
Tried the other motor send to me. Same fault.
Going to strip the machine tomorrow morning and put the working servo motor on the axis giving fault.
Motors are the same except for the break which does not matter as the break motor is disconnected from the machine mechanically.
I do suspect the servo motors to be faulty as they are 2nd hand and can not be guaranteed to be working.( some customers can not afford to pay for new equipment)
The problem is to prove it , which I hope to do tomorrow.
Thx

[hub]

Yes, you're correct, I missed that sorry.
Maybe its the motor then. If it has brushes, change to new ones. If not the windings might be damaged..

Could you maybe check the current when running the servo? (Measure or maybe the servo tuning software has an option to monitor current?) Should be low if not connected to the machine if the servo is ok.

[jacof]

Could you maybe check the current when running the servo? (Measure or maybe the servo tuning software has an option to monitor current?) Should be low if not connected to the machine if the servo is ok.

Hi HUB.
Finally got to the problem today.
Found that the first motor they send was not compatible to the servo drive.
The second motor was compatible , but only realised today that the control s software was to old to accommodate the alpha C servo motor.
Normally you just change par.8_20 for motor model and the control will set the rest of the pre-setted parameters , but my control is to old.
Have to set all servo par. manually.
Well , learned the hard way to either check everything manually, or get the customer to get the right spec parts.
Really appriciate all the input I got from you guy.
As for your question , the current went up to +200% when switching control ready.
THX

[hub]

Ok, glad you got it figured out.