OV Fault Code 8 - AirVolution/AirLegacy Troubleshooting (Public)

A OV fault (fault code 8 on the touchscreen) is a mains overvoltage fault. The VFD has detected that the input power has exceeded the drive's rating. 

Important Note: If you are seeing an "OU" fault code on the VFD screen, this is actually a misread of the OV fault (Overvoltage, Fault Code 8). The display on the VFD can make the letters "O" and "V" appear similar to "O" and "U", leading to confusion. There is no actual "OU" fault code. Please refer to the OV fault code information below.

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.

3. The incoming power is inconsistent. This can be difficult to trace and is most likely the cause of an OV if a fan will run for hours or days without issue before faulting with an OV. This is caused by small, quick spikes in the incoming power that are not detectable unless a power logger is used for a period of time. If this is suspected to be the issue, contact MacroAir Technical Support to review possible solutions.

4. There may be an issue with the motor. Refer to the motor overload troubleshooting.