Applicable Systems
S7-1200
S7-1500
S7-300
S7-400
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SINAMICS
Symptoms
Rectifier unit not ready. The SINAMICS V90 servo drive has detected that the internal rectifier unit is not ready for operation. The drive cannot enable the motor.
Possible Causes
- Input power phase loss (one phase missing from the 3-phase supply)
- Input voltage too low (below minimum rated voltage)
- Rectifier hardware fault
- Internal power supply to the rectifier stage failed
Troubleshooting Steps
- Step 1: Check 3-phase input power supply at drive input terminals L1, L2, L3
All three phases present; voltage within rated range (342-418V for 380V) - Step 2: Verify input contactor or circuit breaker is closed
Contactor is closed; voltage present at drive input - Step 3: Check for blown input fuses
All input fuses intact; continuity confirmed - Step 4: If input power is good and F07802 persists, the rectifier hardware is defective
Drive replacement required
How to Reset
1) Check 3-phase input. 2) Verify contactor/breaker. 3) Check fuses. 4) Replace drive if rectifier is defective. 5) Reset fault.
Frequently Asked Questions
- Q: Can a single-phase input V90 report F07802?
Single-phase V90 models (e.g., 400W frame) can operate on single-phase 230V. F07802 on these models still indicates input power issues or rectifier fault.
- Q: What input voltage range does V90 accept?
3-phase models: 380-480V AC +/-10%. Single-phase models: 200-240V AC +/-10%. Check the drive nameplate for the rated input voltage.
Source: Siemens SINAMICS V90 Operating Instructions, Edition 01/2023
Category: PLC & VFD