PGO PG Disconnection Detected Error in Yaskawa G7 Drive

PGO (PG Disconnection Detected) in the Yaskawa G7 Drive indicates that the Pulse Generator (PG) feedback signal has been lost or is abnormal while the drive is outputting frequency. The G7 continuously monitors encoder (PG) feedback to ensure accurate speed control. If the PG signal is interrupted, wired incorrectly, or unavailable during operation, the drive generates the PGO error and may stop the motor to prevent unstable operation.

PGO PG Disconnection Detected Error in Yaskawa G7 Drive


This error generally indicates a problem with the encoder (PG), PG wiring, power supply, or brake circuit, rather than the inverter power section.

Possible Causes

  • Broken or disconnected PG wiring.
  • Incorrect PG wiring.
  • No power supplied to the PG encoder.
  • Faulty PG encoder.
  • Loose encoder connector.
  • Damaged encoder cable.
  • Brake applied to the motor, preventing encoder rotation.
  • Open circuit in the brake circuit.
  • Faulty encoder interface.
  • Electrical noise affecting the PG signal.

Solutions

  1. Check for a break in the PG wiring.
    • Repair or reconnect any broken or disconnected wiring.
  2. Verify that the PG is wired correctly.
    • Correct any wiring errors according to the drive and encoder wiring diagrams.
  3. Check the PG power supply.
    • Ensure the encoder is receiving the correct supply voltage.
  4. Check the motor brake.
    • Verify that the brake releases correctly and check for an open circuit when using a brake-equipped motor.
  5. Inspect encoder connectors for loose or damaged pins.
  6. Replace the encoder if it is defective.
  7. After correcting the problem, reset the error and verify normal encoder feedback.

Additional Information

The Pulse Generator (PG) provides speed feedback to the Yaskawa G7 drive for accurate closed-loop motor control.

The PGO error is generated when the drive detects that the expected PG feedback is missing or invalid while the inverter is operating.

According to Yaskawa, the recommended corrective actions are to:

  • Repair any broken PG wiring.
  • Correct PG wiring errors.
  • Ensure proper power is supplied to the PG.
  • Check the motor brake for open-circuit conditions if one is installed.

Unlike a motor overload or overcurrent fault, PGO is a feedback signal fault that affects speed regulation rather than the inverter output stage.

Common Symptoms

  • Drive displays PGO PG Disconnection Detected.
  • Motor stops unexpectedly during operation.
  • Speed feedback is lost.
  • Closed-loop control becomes unavailable.
  • Drive trips shortly after starting.
  • Encoder speed reading is missing or unstable.
  • Motor brake may fail to release properly.
  • Repeated encoder-related faults after reset.
  • Inaccurate motor speed regulation.
  • Drive cannot operate in closed-loop mode until the fault is corrected.

Recommended Troubleshooting Sequence

  1. Verify that the error is PGO PG Disconnection Detected.
  2. Disconnect power and follow lockout/tagout procedures.
  3. Inspect the PG cable and connectors.
  4. Check for broken or disconnected wiring.
  5. Verify the encoder wiring against the wiring diagram.
  6. Measure the encoder supply voltage.
  7. Confirm that the encoder is powered correctly.
  8. Check that the motor brake releases fully and inspect for open-circuit conditions.
  9. Test or replace the encoder if necessary.
  10. Restore power and reset the error.
  11. Verify stable encoder feedback during operation.
  12. Test the drive under normal operating conditions.

PGO PG Disconnection Detected Check Table

Check PointAction
PG wiringRepair broken or disconnected wires
Encoder wiringVerify correct wiring
Encoder power supplyConfirm correct supply voltage
Encoder connectorInspect for loose or damaged pins
PG encoderTest and replace if faulty
Motor brakeVerify brake release and check for open circuit
Encoder feedbackConfirm stable speed feedback
Drive operationVerify normal closed-loop operation after repair

Preventive Maintenance Tips

  • Inspect encoder cables regularly for wear or damage.
  • Keep encoder connectors clean and securely fastened.
  • Periodically verify encoder supply voltage.
  • Protect encoder wiring from electrical noise by using proper shielding and grounding.
  • Test motor brake operation during preventive maintenance.
  • Route encoder cables separately from power cables.
  • Replace damaged encoder cables promptly.
  • Record recurring PGO errors to identify intermittent wiring or encoder issues.
  • Verify encoder alignment after motor maintenance.
  • Follow Yaskawa preventive maintenance recommendations for encoder feedback systems.

Proper inspection of the PG wiring, encoder power supply, encoder connections, motor brake, and feedback circuit will help prevent recurring PGO PG Disconnection Detected errors in Yaskawa G7 drives, ensuring reliable speed feedback, accurate closed-loop motor control, and long-term system performance.

Comments

Post a Comment

Popular posts from this blog

Allen Bradley Kinetix 5500 Drive Fault Codes List

Complete guide to Allen Bradley Kinetix 5500 fault codes. Troubleshoot FLT codes, Single-Cable (DSL) feedback errors, shared bus faults, and perform diagnostics via Studio 5000. Kinetix 5500 Fault Codes Reference Table Kinetix 5500 Fault Codes Reference Table Kinetix 5500 Fault Codes Reference Table Fault Code and Meaning Cause and Remedy FLT S03 – MTR OVERSPEED FL Motor Overspeed Factory Limit Fault Cause: Motor speed has exceeded 125% of its maximum speed. Remedy: Check control loop tuning. FLT S04 – MTR OVERSPEED UL Motor Overspeed User Limit Fault Cause: Motor speed has exceeded motor overspeed user limit. Remedy: Check control loop tuning. Increase the Motor Overspeed UL attribute value. FLT S05 – MTR OVERTEMP FL Motor Overtemperature Factory Limit Fault Cause: Calculations based ...
Read more

Danfoss VACON 100 FLOW Drive Fault Codes List

Access the complete reference guide for Danfoss VACON 100 FLOW drive fault codes. Learn to diagnose Multipump communication errors, dry run faults, and use Vacon Live software. VACON 100 FLOW Fault Codes Reference Table VACON 100 FLOW Faults and Alarms VACON 100 FLOW - Fault Tracing Fault Code and Meaning Cause and Remedy Fault Code 1, ID 1 Overcurrent (Hardware Fault) Cause: There is too high a current (> 4 × IH) in the motor cable. a sudden heavy load increase a short circuit in the motor cables the motor is not the correct type the parameter settings are not properly made Remedy: Check the loading. Check the motor. Check the cables and connections. Make an identification run. Set the acceleration time longer (P3.4.1.2 and P3.4.2.2). Fault Code 1, ID 2 Overcurrent (Software Fault...
Read more

ABB ACH580 Drive Fault Codes List

Access the complete reference guide for ABB ACH580 HVAC drive fault codes. Learn to diagnose issues via the Hand-Off-Auto panel, BACnet integration, and Fireman’s Override. The ABB ACH580 is the industry-standard flagship drive for HVACR applications. Designed to control air handling units, cooling towers, and chillers, it ensures critical comfort and safety in buildings. When a malfunction occurs, the dedicated Hand-Off-Auto (HOA) control panel displays a 4-digit code alongside plain-text diagnostics, often integrated directly into the Building Management System (BMS). This guide provides the most updated reference to help you interpret these codes and maintain building environmental standards. ACH580 Fault Codes Reference Table Use the search bar below or browse the table to identify your specific error code: ABB ACH580 Drive Fault Codes List ABB ACH580 Drive Fault Codes List Fault Code and Meaning Cause and Remedy A2B1...
Read more