A 590+ with v8 firmware may throw a "PRE SEQ READY" alarm on the keypad when attempting to enable the drive. The manual recommends to simply replace the power board or chassis.
To attempt to determine a root cause check the following points. If all of the below are functioning as intended, the power board or chassis must be replaced as stated in the help file.
- Missing AC Mains
- Check to make sure you are supplying power to each of the three input phases. The 590+ drive will not run properly on single phase supply. Make sure this voltage is nominal to what the drive expects (above the minimum requirement).
- Check the coding fuses
- The exact location of these fuses are dependent upon the frame size of your drive. They include, but may not be limited to: FS1,FS2,FS3 and FS5,FS6
- Consult the 590+ manual for fuse locations from AC mains into the drive.
- The AC contactor should be closed.
- See "CONTACTOR CLOSED" on the "Sequencing" function block. This should be TRUE when you enable the drive. If not, you would normally recieve other faults. Verify your programming logic and additional points in this FAQ: AC Contactor won't close?
- The "PLL STATE" on the "Phase Locked Loop Function" block must be LOCKED
- Normally the PLL will reside in the LOCKED state after close of the 3-phase line contactor. It may cycle through other states when transitioning to LOCKED, but it should be static at LOCKED during operation.
- Right click the function block to observe the help file for a list of the additional states.
10OCT19 CW JD