IMPULSE•G+/VG+ Series 4 Technical Manual
November 2022
Page 205
6.2.2 PGO-X-S/PGO-X-H–Pulse Generator Signal Fault
Definition
A Pulse Generator Signal fault indicates that the VFD has detected a problem with encoder feedback. This fault will
typically occur if the VFD doesn’t receive any encoder feedback pulses while it is commanded to run or encoder
wiring has a discontinuity.
NOTE:
The “X” in PGO-X-S and PGO-X-H depicts either a “1” if the PG-X3 is seated in connector CN5-C, or a “2”
if the PG-X3 is seated in connector CN5-B.
Corrective Action
1. Do
NOT
continue to operate the hoist in the event of a PGO-X-H fault or repeated PGO-X-S faults.
NOTE:
Continued attempts to operate the hoist with PGO faults can result in loss of control of the load.
2. As a precaution, the Load Float Time (C08-10), should be set to zero until the source of the PGO Fault has
been determined and corrected. Disable PGO hardware detection with F01-06 or F01-16.
3. Check the alignment of the encoder pulse wheel and sensor head, the encoder shaft coupling, or check for a
failed encoder sensor head. If one of these conditions exists the VFD may get erratic pulse signals or no signal
at all causing a Speed Deviation or PGO fault. Make repairs before attempting to operate the hoist.
4. If the encoder appears to have no mechanical problems, the encoder cable should be checked for damage.
•
Each of the encoder wires should be checked for continuity.
•
The wires should be checked for shorts between any two wires.
•
The wires should be checked for shorts to the shield or ground.
•
Visually inspect the cable for damage that may be causing intermittent problems.
5. If the encoder feedback system checks out, then check for physical obstruction to motor rotation such as the
brake failing to open.
6. After corrective action has been taken and the fault no longer occurs, set the Load Float Time (C08-10) back to
its initial value.
