Siemens Drive Fault Code 7902 Site
Troubleshooting Siemens Drive Fault Code F07902: Causes and Solutions
Save the parameters from RAM to ROM to ensure the fault does not return after a power cycle. Preventive Measures for Plant Operations
A stalled motor fault rarely stems from a single isolated issue. It is typically triggered by a combination of mechanical resistance, incorrect electrical parameters, or hardware degradation. The root causes generally fall into four categories: 1. Mechanical Blockages and Overload
Verify U-V-W connections for the motor.
Detected at very low speeds/standstill when the speed controller is at its limit. Motor Overspeed siemens drive fault code 7902
Tell me the exact Siemens drive model (e.g., SINAMICS G120 CU240E-2 ) and whether you have an encoder or are running in V/f or vector control.
Inspect the encoder cables for shielding defects, loose connections, or proximity to high-voltage power cables (EMI noise can corrupt encoder signals).
The root causes generally fall into four primary categories:
: The maintenance interval value was set too low during commissioning, causing premature trips. Steps to Troubleshoot and Resolve the Fault Troubleshooting Siemens Drive Fault Code F07902: Causes and
Primarily seen in SINAMICS S120 and G120/G120XA drives using Vector Control (VC) or Sensorless Vector Control (SLVC).
Look at parameter p2175 (Motor stalled speed threshold) and p2177 (Motor stalled delay time). If your application requires a long time to break stiction, safely increase the delay time slightly to see if the drive passes the initialization phase.
| 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 |
Increase the ramp-up time in p1120 .
Check parameters to adjust the stall detection sensitivity. If using an encoder, check for "inverted" encoder signals. Specific Notes for G120XA Converters
Open the motor terminal box. Verify the position of the shorting links (jumpers).
Disclaimer: This information is based on standard SINAMICS G120/S120 documentation and community feedback within the Siemens SiePortal .
. "The load is heavy today. The drive is timing out before the motor can overcome the inertia." The root causes generally fall into four categories: 1
If fault appears at start command: