OSF Fault Code 19 - Direct Drive Troubleshooting (Public)

A OSF fault (fault code 19 on the touchscreen) is a mains overvoltage fault. The VFD has detected that the input power has exceeded the drive's rating. There are two possible causes for this:

1. The input voltage is too high. You may see this if, for example, a 240V 3/PH drive is connected to 480V 3/PH input power.

2. There was a power surge. If the incoming power has returned to acceptable levels, this fault code can be cleared to resume fan operation.

If a drive displays OSF and the above has been checked, a replacement drive may be necessary. Contact MacroAir Technical Support for assistance with ordering any necessary parts.