How to calculate the inrush current of the shutter motor?
Please be aware of the inrush current of the motor of your shutter when using our shutter relay. The inrush current is mostly not found in the technical data of your motor, but can be calculated in the following way.
Nominal current = Power / 230V
Maximum current = Nominal current x 1,414
Inrush current = Maximum current x 2
A shutter motor with a power of 120W, the calculation would look the following:
Nominal current: 120 W / 230V = 0,52A
Maximum current: 0,52A * 1,414 = 0,74A
Inrush current: 2x 0,74A = 1,48A
A shutter motor with a power of 120W / 0.52A has an inrush current of 1.48A for the first 20-30ms.
Please make sure, that the inrush current of your motor is lower than the maximal load of our shutter relay. Otherwise, the shutter relay can be damaged. If the inrush current of your shutter is higher, please use a suitable cut-off relay between the shutter relay and the motor.