MPA Drive Setup Procedure

[billbrwn]

Looking for an MPA Drive Setup Procedure. A step by step procedure would be nice if I were to replace a burnt out servo amp with another of the same model.

There's tons of info for the MPA drives here: http://www.obsoleteindustrial.com/roundtable/electrical-and-electronic/mts-systems-mpa-460-servo-drive/

Just need a simple drive setup procedure if possible....

Thanks again

[benklassne]

There's plenty of information in the other MPA drive post but I actually have written a simple setup procedure for how I would do it.

So if you have a bad drive and you are replacing it and would like to setup the new drive, this is what I do:

• Remove the cover and duplicate the jumper settings on the new amp to match the old amp
• Set the trim pots to match the old amp (I drew diagrams of the old amp jumpers, dip switches, and trim pots included below).
• Disconnect COM+ and COM- command signal wires
• Adjust the balance pot with a small screwdriver to eliminate any drifting of the motor (by the way, if safety is a concern you should disconnect the load from the motor in case the motor spins unexpectedly)
• With those steps complete, you may be able to run your equipment normally and monitor with an o-scope for overshoot using the VELOCITY and GND test points
• Connecting an o-scope to the CURRENT and GND test points displays the actual current at the instant of motion and may also provide you with some valuable info regarding the drive setup

The initial startup guide in the manual is also good but what I have learned is that you get better results faster when you simply match up the new and old drives exactly first, then go from there with fine tuning.

[allentrop]

I have some experience with these servo amplifiers. Here are bits of info for amplifier setup.

The amplifiers should be checked in an open loop condition by disconnecting the command signal wires COM+ and COM- . You should be able to adjust the balance pot to elimate motor drift or at least get the shaft close to being stationary. Some drifting is OK if you can't stabilize it completely.

By connecting a 9v battery (or as low as a 5v DC supply) to the command signal in series with a push button or an electronic recycler (repeat cycle timer), you can initiate motion. You should only do this with no load attached to the motor shaft because you are going to initiate motion.

Be sure to use an ungrounded plug on the oscilloscope!!! With the scope connected from VELOCITY to GND you can monitor for overshoot. I learned this lesson the hard way because I created some kind of ground loop which skewed by waveform and gave me confusing results so be careful here.

This test point will display the actual velocity of the motion you have initiated.  Any overshoot that shows up can be adjust to a minimum using the LEAD pot.

The scope connected from CURRENT to GND will display the current draw at the instant of the motion and this is also indicated by the bi-color current LED. Red means you working it hard.

The SIGNAL pot will adjust the overall speed of the motor and can be observed using a handheld tachometer while a constant movement is initiated. I was insructed by tech support years ago to leave the signal pot at the midpoint (12:00) if we ever replace an amplifier.

The setup and start up procedure are in the manual are good procedures and should be followed closely.

I have two of these still in service. These are the approximate locations of the pots on my amplifier:

TOP Motor: bal 7:00; cur 2:00; resp 2:00; sig 9:00; lead 5:00
BOTTOM Motor:     bal 2:00; cur 2:00; resp 2:00; sig 9:00; lead 5:00

Maybe this info can help you out too.

[billbrwn]

Thanks guys, I have her dialed in pretty well. Thanks for the good info!!