OrP Input Phase Loss Fault in Delta C200 Drive

OrP Phase Lacked (Input Phase Loss) in the Delta C200 Drive indicates that the drive has detected the loss of one or more incoming AC supply phases. The drive continuously monitors the three-phase input power to ensure balanced operation. If one input phase is missing, disconnected, or significantly unbalanced, the drive generates the OrP (Phase Lacked) fault to protect the rectifier, DC bus, and power electronics from abnormal operating conditions.

This fault generally indicates a problem with the incoming power supply, input wiring, protective devices, or input rectifier, rather than a fault in the motor.

Possible Causes

• One incoming AC phase is missing.
• Blown input fuse.
• Tripped circuit breaker.
• Loose or damaged input power cable.
• Poor terminal connection at the drive input.
• Single-phasing of the power supply.
• Low input voltage on one phase.
• Severe phase voltage imbalance.
• Faulty upstream contactor.
• Damaged incoming power cable.
• Defective input rectifier module.
• Faulty phase detection circuit.
• Incorrect power supply wiring.
• Utility power supply problem.
• Internal drive hardware failure.

Solutions

• Cycle power to the drive and check whether the fault clears.
• Verify that all three input phases are present.
• Measure the input voltage on all phases.
• Check for blown input fuses.
• Inspect the circuit breaker for proper operation.
• Tighten all input power terminals.
• Inspect input power cables for damage.
• Verify correct input wiring.
• Check the upstream contactor for proper operation.
• Measure phase-to-phase voltage balance.
• Inspect the incoming power supply for interruptions.
• Check the input rectifier if phase loss is not present externally.
• Replace defective fuses, cables, or contactors if necessary.
• Replace the input rectifier or drive if internal hardware is defective.
• Contact Delta technical support if the fault persists after inspection.

Additional Information

The Delta C200 drive continuously monitors the three-phase AC input supply before converting it into DC voltage through the internal rectifier.

If one phase is lost, the drive experiences:

• Reduced rectifier performance.
• Increased ripple on the DC bus.
• Higher current in the remaining phases.
• Increased stress on the input rectifier.
• Reduced output capability.

To prevent overheating and possible damage to the power components, the drive generates the OrP (Phase Lacked) fault and stops operation.

Common causes include:

• Blown input fuses.
• Loose input terminals.
• Failed upstream contactors.
• Utility power interruptions.
• Internal rectifier failures.

Unlike a Motor Phase Loss fault, OrP specifically monitors the incoming AC supply, not the motor output.

Common Symptoms

• Drive trips with OrP Phase Lacked fault.
• Drive will not start.
• Fault appears immediately after power-up.
• One input phase measures low or zero voltage.
• Input fuse repeatedly blows.
• Circuit breaker trips unexpectedly.
• Motor cannot be energized.
• DC bus voltage becomes unstable.
• Fault clears temporarily after power cycling.
• Drive repeatedly trips when the supply becomes unbalanced.

Recommended Troubleshooting Sequence

1. Cycle power to the drive.
2. Measure the voltage on all three input phases.
3. Check for blown input fuses.
4. Inspect the circuit breaker.
5. Tighten all input power terminals.
6. Inspect input power cables.
7. Verify correct phase wiring.
8. Check the upstream contactor.
9. Measure phase voltage balance.
10. Inspect the incoming utility power supply.
11. Check the input rectifier if the supply is normal.
12. Replace defective fuses, cables, or contactors if required.
13. Replace the rectifier or drive if internal hardware has failed.
14. Verify stable three-phase input power.
15. Contact Delta technical support if the fault persists.

Input Phase Loss Check Table

Check Point	Action
Power cycle	Restart the drive
Three-phase input	Verify all phases are present
Input voltage	Measure phase-to-phase voltages
Input fuses	Inspect and replace if blown
Circuit breaker	Verify proper operation
Input terminals	Tighten all connections
Power cables	Inspect for damage
Input wiring	Verify correct phase connections
Upstream contactor	Check proper operation
Phase balance	Verify balanced input voltages
Input rectifier	Inspect if supply is normal
Delta technical support	Contact if the fault remains after inspection

Preventive Maintenance Tips

• Periodically inspect input power terminals for tightness.
• Check input fuses and circuit breakers during scheduled maintenance.
• Measure incoming three-phase voltage balance regularly.
• Inspect power cables for signs of overheating or insulation damage.
• Verify proper operation of upstream contactors.
• Maintain a stable and balanced three-phase power supply.
• Protect the drive from voltage disturbances using appropriate power quality equipment where required.
• Inspect the input rectifier for signs of overheating during preventive maintenance.
• Replace damaged cables, terminals, and protective devices promptly.
• Record recurring input phase loss faults to assist long-term diagnostics.

Proper verification of the three-phase input supply, routine inspection of input fuses, circuit breakers, power cables, terminals, and upstream contactors, along with monitoring of phase voltage balance and timely replacement of defective input components, will help prevent recurring OrP Phase Lacked (Input Phase Loss) faults in Delta C200 drives, ensuring reliable power conversion, stable DC bus operation, and dependable long-term performance of the drive system.