How To Replace an MPA Amplifier?

The Compax3 series family servo drives are a higher performing digital servo amplifier available in standard and high voltages for suggested replacement of the analog design MPA amplifiers.

Below table lists each MPA drive, and the recommended replacement drive. When multiple drives are listed as the replacement, it is because one Compax3 drive had slightly less output current capability than the MPA, but it would work in most cases. It should be noted that the MPA drives are rated in Apeak of sine, meaning the MPA-03 has a continuous current rating of 3Apk, and peak current rating of 6Apk. Correspondingly, the Compax3 is rated in Arms, meaning that an S025V2 has a continuous current rating of 2.5Arms, and a peak rating of 5Arms. In order to convert the current rating of the MPA to Arms, divide by 1.414. For example, since the MPA-03 is 3Apk, we divide 3 by 1.414 and get 2.12Arms. Therefore, the S025V2F10I10T10M00 is the recommended replacement for the MPA-03.

Warning: Most MPA drives could run on either single or three-phase power. All Compax3 drives, except the S025V2 and S063V2, are three phase only. The S025V2 and S063V2 are single phase only. If single phase is being currently being used with the MPA, it is important to know if three phase power is available before proceeding with the upgrade.

For full details in upgrading to the Compax3 see the attached document:

How to Upgrade from MPA servo amplifier to the Compax3 digital servo amplifier (updated to rev 3 on 4/6/22)

Crossing over MPA to C3 Pinouts QuickReference

Note the MPA inputs were NPN logic. Ramco Innovations makes a small RCM-1X3 that converts 3 NPN circuits into 3 PNP circuits that's good for 10-30vdc signals and works with the Compax3. It's small and fits onto din rail. This would save re-wiring the controller or PLC:

 https://www.ramcosensors.com/pdf/NPN%20to%20PNP%20Converter%20Modules/RCM%20Series/RCM1x3.pdf