Applicable Systems
DVP
AH500
AS300
C2000
MS300
Symptoms
The drive trips. The keypad displays E08, indicating output phase loss. The drive detects that one of the three motor output phases is not carrying current.
Possible Causes
- Motor cable disconnected or broken on one phase
- Loose terminal connection on one output phase
- Motor winding open circuit
- Drive output stage failure on one phase
Troubleshooting Steps
- Step 1: Inspect all motor cable connections
All connections are tight - Step 2: Measure continuity of each motor cable conductor
All three phases show continuity - Step 3: Measure motor winding resistance on all three phases
Winding resistances are balanced - Step 4: If no external cause is found, drive output may need service
Drive needs service if phase loss is internal
How to Reset
To reset: 1) Fix the disconnected or broken phase. 2) Press RESET. Caution: Running a three-phase motor with a missing phase causes overheating. The drive trips to protect the motor.
Frequently Asked Questions
- Q: What damage can output phase loss cause?
A three-phase motor running on two phases draws excessive current, causing rapid overheating. Stator windings can burn out within minutes. The drive's phase loss protection prevents this.
- Q: How do I test for an open motor winding?
Measure resistance between each pair of motor terminals (U-V, V-W, U-W). All three readings should be nearly equal. A significantly higher or infinite reading indicates an open winding.
Source: Delta C2000 Series User Manual, 2023
Category: PLC & VFD