1995 VMC15 Error#3 Motor overload

[Billet Sean]

I have a VMC 15 and when i go to cold start it in the morning i keep getting "X-axis Faults as Follows: Error# 3, Motor Overload." It happens every morning. But after a bit, it's fine. It still runs good parts. The Y and Z axis are fine. I can jog them around in the morning even when the X axis trips out. As soon as i flip the dial to the X-axis, it trips out. My voltage is good. The machine sounds great. Just not sure what the problem is. It takes about an hour to get the thing up and running in the morning. Any help would be greatly appreciated! Thanks.

[AndyB]

It could be 1 or 2 things : the amp card and/or the servo motor.

to do a quick check on the motor use an ohmeter on the white and brown leads at the amp card - resistance should be 1-3 ohms(approx). if it reads higher or infinity then you have a motor problem.(rebuild or replace motor)

to check the amp card swap the X and Y amp card connections. If the problem moves to Y, then the amp card is bad. If the problem stays in x then the amp card is ok.

also be sure to check the motor connections inside the motor to see there is any moisture/leakage issuses.

[ASIGuy]

Andy is correct. Also, if you have access to a megger this will tell your story. Meg the motor from the amp card. You must remove the white and brown wires from the amp card first as the megger sends big voltage out the test leads and this is not good for the amp card. After the wires are removed, meg each one, one at a time to ground. A good reading is more than 100, 10 - 100 is maybe fine, but less than 10 you will very likely have issues just like this. However, at this point you don't know if it's the wires or the motor. Now you have to disconnect the red and black wires from the white and brown at the motor and check first the red motor wire to the motor case, then the black and you interpret the readings the same. If good, you have a bad wiring harness, if bad, replace the motor.

If you do not have access to a megger, just replace the suspect motor with the Z axis motor because it's the easiest to change out and see if the problem moves with the motor. If so, replace the motor, if not, replace the cabling. FadalCNC.com has motors and cables in stock if you need anything.

[Billet Sean]

I just swapped the amp cards and the problem moved to the Y axis. So I need a new amp card. Glad it's not the motor! Amp cards aren't that much. Thanks for all the input! I appreciate it.

[ASIGuy]

Billet Sean,

Not so quick. There is a turn pot on the edge of he card labeled "Cur" or "Gain" usually. Make sure it is fully clockwise before changing it out. Sometimes it gets shipped from the factory less than full out, or a service tech tunes your amps and tweaks it down for some ungodly reason during his process, so just verify it's maxed out before tossing in the towell on the amp card. Also, anytime you move amps from one slot to another, or replace with new, you will need to re-tune the amp cards in your machine to be sure they are working in harmony. Here is link to the maintenance manual with the full proceedure and I have attached a short version.

http://www.fadalcnc.com/fadal_Tech_Docs1.htm

Under "Maintenance Manuals" look for "Sect 6-Axis Drive Systems" Lots of good stuff in there about your amp cards and how they work.

Good luck.

Brian Denny
ASI Machine & Supply

[Neal]

When your machine is cold, turn on the power but DO NOT hit tthe green button. Look at the controller cards and/or amplifiers. If they are on, you might need the ELE-1633 contactor kit. This replaces a leaking SS relay.

Neal