[DZANDF]

Greetings all,
Just took delivery on a used 2000 Haas VF3 with Vector drive. Paid for a tech to check it out before we purchased it and it ran fine. Get it home and set it up and on starting it up we get a Alarm 123 Drive Fault that will not reset ( does not give companion low or high voltage alarms ). So started trouble shooting with info from this sight and come up with the following..

The incoming voltage to the drive is 230 +/- 4 volts on all legs. The Drive DC Buss voltage is 330 which agrees withing a few volts of what the controller says the voltage is. The motor leads ohm out at .4 and the regen resistor bank at 8. Neither show any shorts to ground. On the drive the ON light is green, the high voltage light light is on, the fault light is off, and the regen fault light is off. The cabling between the drive and the Mocon & I/O board seems to be fine.

In the “diagnostics vector bits” the spindle fault shows 1. The spindle encoder seems to work as when you turn the spindle by hand as the vector bit for spindle stopped changes state. I disassembled the drive ( after the power had drained off ) did not see any obvious signs of damaged or cracked components. The diode bridge seemed to check out fine, but it should since I was getting DC out of the drive. I did not check the main capacitors, but as long as the unit stays charged they seem to be working.

Called Haas Tech Support and they said the only thing left was to check if the DC buss is shorted by disconnecting the power cable to the axis drives, check the cable to the Mocon board, and check the 12 and 5 volt power to the Mocon Board. Which all checked fine.

Which means it is either the Vector drive or the Mocon is bad. And from what problems people seem to have it seems it most likely is the Vector drive. But before I send of for a rebuild I have 3 questions that I hope some of you can help me with.

First is there anything I missed that I should check?

Second I know I can force a low voltage and high voltage alarm through the cables to the I/O board at J11 and the Mocon Board at J17. But does anyone know what wires to jumper or unplug from the the cable from J3 to J33 to fool the controller to thinking the drive is fine? That way I would know for sure if it is the drive or board that is the problem. I have the schematics that Tayfun did up on the vector drive, but it is way beyond me to read it will enough to know which leads are sending the fault signal and what kind of signal it is sending be it volts, mili-amps or digital.

Third I heard that my local Haas dealer may not be the best bet for service. Does any know of a good independent tech in the Portland Or. area for Haas's?

Thanks for any help at all which you may be able to give.

[DZANDF]

Update,
Talked to a drive rebuilding shop today. Doesn't seem to be any way to easily trick the mocon to think the drive is not faulted. Did give another test to try. While looking at the vector bits on the diagnostics page press RESET several times. If the drive is the problem the spindle fault bit should momentarily go off, then back on. Tried that and it would not go off at all. So he said, it is still most likely (90%) the drive, but now it is possibly the mocon board. So since we have time as we are still using our old CNC, we shipped the drive off to him to test it. Will let you know the results. If it is the Mocon, they also rebuild them.

[Precision MT]

Replace the vector drive, trust me. I rebuild Haas vector drives, I can get you one for a lot less than the HFO will sell it to you, with double the factory warranty (180 days). This is very common, especially after power outages.

[homey263]

It is without a doubt your Vector Drive. If you send it out to be rebuilt, ensure the person doing it does not include the newer "SMART AMP" technology to it that the newer drives come with, otherwise you will have serious issues between the VD and your Servo Amps.

[DZANDF]

We received the report on the drive from the rebuilders. They said it was sending a false thermal alarm to the mocon board. That the drive cleared the alarm when it first started up which was why the drive fault light was not on. But it never stopped sending the fault signal to the mocon. Stated it was the first time they had ever seen that problem.

[snowshooze]

I'd like to hear the rest of this story. 123 at start here too, in TM2