Contactor failure is one of the common malfunctions in frequency converter operation. For Oulu frequency converters, a contactor fault is displayed as ERR/FU17 on the operation panel. The causes and troubleshooting methods for contactor failure are as follows:

1. Abnormal drive board or power supply: Replace the drive board or power board.

2. Contactor malfunction: Replace the contactor.

3. Abnormal lightning protection board: Replace the lightning protection board.

4. Modify parameter P9-12 to 01/00: Disable the relay protection function.