In the graphs here, the current increase caused by reverse rotation can be compared. During the abnormal rotation condition the current is increased nearly 3 times over the normal operation state. This increase in current would lead to permanent damage of the fan electronics if left unchecked. To prevent this, most Sanyo Denki fans include circuitry to shut off the fan operation and prevent any damage. Once the reverse rotation protection has engaged it is unlikely the fan will be able to start without a reset. As part of the installation parameters, the Sanyo Denki catalog recommends starting up all fans at the same time to prevent an imbalance of pressure on all fans within a system. Yet more precautions may still be required to fully mitigate reverse rotation.