Verify that all electrical connections are secure and that there are no signs of damage or wear on cables and connectors.
Here is the breakdown and common solutions for this fault.
Does this fault happen or randomly during operation ? siemens drive fault code 7902
In technical terms, the drive’s internal motor model compares the expected motor speed (based on the setpoint) against the actual speed feedback (or an estimated value). If the deviation between what should be happening and what is happening exceeds a predefined threshold for a set amount of time, the drive shuts down and raises the F7902 fault to prevent damage to the mechanics, the motor, or the drive itself.
This fault, often displayed as F07902 or simply 7902 on the drive’s operator panel, indicates a critical mismatch between the commanded speed and the motor's actual behavior. Simply put, the drive is demanding motion, but the motor is not responding appropriately. If you are facing this issue, this comprehensive guide will walk you through everything you need to know, from the fundamental cause of the error to advanced parameter adjustments that can resolve it. Verify that all electrical connections are secure and
In some applications, immediate trip on overtemperature is too aggressive. You can modify the response:
Begin with verifying that the PLC master is actively exchanging cyclic data with the drive’s configured station address. Then check hardware integrity of the bus cable and termination. If the issue persists, match telegram settings exactly between the drive (P0922) and the master’s hardware configuration. In technical terms, the drive’s internal motor model
The motor is struggling to turn the mechanical load.
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).