P1 Precharge

What does 11101 mean?

The DC bus voltage did not meet the conditions required to close the molded case switch (MCS) within the timeout period for port 1. This includes ensuring the DC bus input is not overvoltage or undervoltage, and the DC bus delta voltage (Vbus_in - Vbus_out) is less than 25V. Failure to precharge can prevent the drive from starting.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check for proper operation of the molded case switch (MCS) and its auxiliary contacts; ensure they are responding correctly.

2. 4

   Inspect the precharge circuitry and components (e.g., resistors, contactors) for signs of failure, damage, or loose connections.

3. 5

   Ensure the precharge timeout period is adequately configured for the system's capacitance and startup requirements.