VFD Fault Code OBF

If a VFD stops due to a fault code and shows on the screen code OBF this is a code meaning there was overvoltage during deceleration. This is most frequently seen on a belt conveyor system where there are many cars loaded and the wash stops for whatever reason. The momentum of the cars can cause the belt to continue forward which is realized by the VFD system. The code typically doesn't mean there is any concern and the wash can simply be restarted. The cause is related to the deceleration rate set in the VFD which is how fast the belt will slow down when it's stopped. To compensate for iniertia you don't want to stop the belt on a dead stop, but rather cost. If the fault occurs frequently you may want to increase your deceleration time therefore reducing the chance of inertia exceeding the decerleration timing of the belt.