| Drive Family | Fault Code | Notes | |--------------|------------|-------| | Sinamics S120 | F07902 | Also logs additional info in r0949 (phase affected: 1=U, 2=V, 3=W) | | Sinamics G120 (CU240E) | F07902 | Can be temporarily inhibited via p2118/p2119 (not recommended for permanent fix) | | Masterdrives (6SE70) | F023 or F024 (older codes) | 7902 appears as “Phase failure output” in newer software versions | | Simotion / Sinamics S150 | F7902 | Same root cause; check also motor holding brake wiring |
The power unit cannot supply the required startup current. 3. Troubleshooting & Solutions (Step-by-Step) Follow these steps to diagnose and clear the fault: Re-commission Motor Data (Crucial): Perform a factory reset of the converter. Set p0010 = 1 (Quick commissioning). Enter exact motor nameplate parameters: Rated voltage ( ), current ( ), power ( ), Power Factor ( ), and speed ( Set p3900 = 3 (Quick commissioning for motor parameters). siemens drive fault code 7902
Set p1200 = 1 if the motor is still turning when the start command is given. Hardware Inspection: | Drive Family | Fault Code | Notes
Siemens drives do not rely solely on external sensors. They use internal at the inverter’s output stage. When the motor is running, the drive expects balanced currents. If one phase deviates by more than a programmable tolerance (typically set via parameter p3230 in Sinamics), the drive triggers fault 7902. Set p0010 = 1 (Quick commissioning)
"It’s a 7902," Marcus said, reading the 7-segment display on the BOP (Basic Operator Panel). "Just '7902'. I tried resetting it, but it just clicks and throws the same code again."