LIN (nn LINK FAULT) fault will appear when there is a communication error between the cell control board and the main control board. It will occur when a response has NOT been returned within 1 ms or longer in the communication cycle between the boards. 

First Cell		Second Cell		* Third Cell
nn Link Fault	Related Phase	nn Link Fault	Related Phase	nn Link Fault	Related Phase
A1 LINK FAULT	U Phase	A2 LINK FAULT	U Phase	A3 LINK FAULT	U Phase
B1 LINK FAULT	V Phase	B2 LINK FAULT	V Phase	B3 LINK FAULT	V Phase
C1 LINK FAULT	W Phase	C2 LINK FAULT	W Phase	C3 LINK FAULT	W Phase

* Note: A third cell is only available on certain MV1000 models. 

The following steps will help when troubleshooting a LIN (nn LINK FAULT) fault: 

1. If the control board was recently replaced on a MV1000 drive, the kVA must be set to match the proper model number.
   • Refer to document: Setting the proper kVA code for oPE01 fault on a MV1000 drive
2. If the LIN (nn Link Fault) continues, turn off power to the drive.
3. Match the fault with the cable connection

   First Cell		Second Cell		Third Cell
   nn Link Fault	Cable Connection	nn Link Fault	Cable Connection	nn Link Fault	Cable Connection
   A1 LINK FAULT	U78	A2 LINK FAULT	U81	A3 LINK FAULT	U84
   B1 LINK FAULT	U79	B2 LINK FAULT	U82	B3 LINK FAULT	U85
   C1 LINK FAULT	U80	C2 LINK FAULT	U83	C3 LINK FAULT	U86

4. Make sure the optical fiber cable between the control board and the cell control board is seated securely and correctly. Re-seat as necessary.
   
5. Apply power to the MV1000.
6. If the fault continues the fiber cable, control board or the cell control board may need to be replaced.