P2 Precharge

What does 11201 mean?

The DC bus voltage did not meet the conditions required to close the molded case switch (MCS) within the timeout period for port 2. 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.

• Input AC line voltage (Port 2) is significantly outside the drive's specified operating range (e.g., below 340V AC or above 480V AC).
• Failure of the precharge resistors (Port 2) due to an open circuit, preventing proper DC bus charging.
• Precharge contactor (Port 2) stuck open or its coil failed, preventing the main DC bus connection from closing.
• Shorted DC link capacitors or a permanent short on the DC bus (Port 2) preventing precharge completion.
• Faulty DC bus voltage measurement circuit (Port 2) providing incorrect precharge status to the controller.

Click steps to track your progress.

1. 1

   Measure the 3-phase AC input voltage at terminals R, S, T (Port 2) to ensure it is within the drive's specified limits.

2. 2

   Measure the resistance of the precharge resistors (Port 2) to confirm they are not open circuit or shorted.

3. 3

   Verify the operation of the precharge contactor (Port 2) by checking coil voltage and contact continuity across its main poles.

4. 4

   Measure the DC bus voltage across the positive and negative terminals (Port 2) during an attempted precharge cycle.

5. 5

   Isolate the drive output by disconnecting the motor (Port 2) and attempt precharge to rule out motor or cable faults.