Motor Softstarter

Hi everybody,

I need some help with softstarters. I have a 3-phase 15kW motor which is used to drive a large blower fan and Im planning to use a softstarter to start the motor to limit the starting torque. The motor nominal speed is 1460 rpm and this speed is reduced to about 500 rpm by a gearbox coupled to the fan. The motor rotates the fan in the clockwise direction.

The problem is that the fan may rotate in any direction when the motor is not running due to the wind blowing into its blades. When there is very strong winds the fan may rotate at speeds close to 500 rpm or even more. Its not a problem as long as the wind blows the fan in the clockwise direction. It may be a problem when the wind blows the fan in counter clockwise direction.If when this happens the softstarter starts the motor, will the regenerative braking action harm my softstarter?

Furthermore, the start ramp will be used to brake the motor rather than starting it, thus the motor will be started as if it was operated direct online.How can i solve this problem?

You can buy an 'Inverter' ready made, i.e. from Panasonic. Inverters - INVERTER - Panasonic Electric Works UK Ltd. -

Standard off the shelf factory made VFD (Variable Frequency Drive) will do everything you need and more. Plus meet codes and will save much time and money.