Applicable Systems
Engel Victus
Symptoms
The servo drive displays Er.990, warning of an input phase loss. The drive detects that one input phase is missing or the input power wiring is incorrect.
Possible Causes
- One of the three input phases is missing due to a blown fuse
- Input power cable loose or disconnected on one phase
- Phase sequence incorrect or single-phase power connected to three-phase drive
- Input contactor or circuit breaker defective on one phase
Troubleshooting Steps
- Step 1: Measure all three input phases at drive power terminals
All three phases must read within rated voltage range and be balanced within 2% - Step 2: Check input fuses for all three phases
Replace any blown fuses and investigate root cause before re-energizing - Step 3: Inspect input wiring and terminal connections
All terminals must be torqued to specification and cables must be intact - Step 4: Verify phase sequence is correct for the drive
Phase sequence must match drive requirements; incorrect sequence can cause motor reversal
How to Reset
To reset: 1) Restore all three input phases. 2) Verify phase sequence. 3) Power cycle the servo drive. Caution: Running with phase loss causes severe current imbalance and can permanently damage the inverter.
Frequently Asked Questions
- Q: Will Er.990 clear automatically when power is restored?
The warning may clear automatically, but the drive must be power-cycled to fully reset the fault state and resume normal operation.
- Q: Can the injection machine run on two phases temporarily?
No. The servo inverter requires balanced three-phase input. Two-phase operation causes immediate inverter damage due to current imbalance.
Source: Engel Servo Drive Controller Manual, Alarm Code Reference Er.990, MXA82A-064-503-00/F
Category: Injection Molding