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F18 or F19 Code Help – Encoder Phase Loss

F18 & F19 (MMX/MMV™ Only): Encoder Phase A or Phase B

Code Meaning: Power loss in phase A (F18) or phase B (F19) wiring from the encoder and/or main power loss to the encoder.

Further Information/Troubleshooting Tips:

  1. Check the encoder coupling. Make sure it is not loose and make sure the encoder does not tilt or wobble while the motor is being driven. Tighten couplings and brackets as necessary. If the physical elements of the encoder appear fine, check the wiring next.
  2. Measure the DC voltage from the drive to the encoder at 0V and +V. If no voltage can be measured there, remove the leads from those terminals and re-measure. If a voltage is present when no leads are connected, verify the wiring for your encoder and test again.
  3. If voltage is present at 0V and +V, measure for DC voltage across terminals A+/A- (for F18) and B+/B- (for F19). You should have voltage similar to the voltage across 0V and +V (it may be positive or negative). If you do not see the appropriate voltage on the phase terminals, verify the wiring and connections for your encoder and test again. If the wiring is correct, and the problem persists, you may have a problematic encoder.

Call PE® for further assistance.