1Powerful motor controller supports that no need to connect bypass contactor, which can be economical and practical. 2Fit for soft start of water pump, fan, vehicle and ordinary single-phase motor, such motor start module keeps super simple wiring. 3Made of materials in high quality, motor start board can be easy to use in the practical life, which makes itself getting great popularity. 4Single-phase motor start module supports the ability to replace adjustable auto-transformer, inverter soft start, etc. 5No extral step is required when you use such motor start board to controll and the operation is simple.Item Type: Motor start board Type: Module / Module + Radiator (optional) Model: SSR-100WA-R(4KW)(with soft start without soft stop) Voltage Compatibility: Single-phase 220VAC, 2-phase 380VAC, Frequency: 50-60Hz Soft Start Time : Adjustable from 0-30 seconds (the soft start time refers to the whole process of 0-220V, 0-380V) Starting VoltageAdjustable from 0-50% to the rated voltage (220-380V) Two Ways to Use: 1. When the switch is closed, the main power supply is energized and the soft start begins. 2. Use the switch to control, start by closing the soft start, open the stop When the starting potentiometer is adjusted to half, the starting is 200V, The maximum time of the soft start potentiometer is 30 seconds, which corresponds to the full range of 380V. For Example: When Completely Adjusted to Minimum: Initial voltage 0V soft start 0 seconds (0 seconds is not recommended) Power Supply 220V: When completely adjusted to half, the initial 55V, soft start time is about 22 seconds Power Supply 380V: When completely adjusted to half, the initial 95V, soft start time is about 22 seconds Power Supply 220V: When completely adjusted to the maximum, the initial voltage of 110V to 220V takes 15 seconds Power Supply 380V: When completely adjusted to the maximum, the initial voltage 190V to 380V takes 15 seconds Size1 : Approx. 92mm / 3.6in Approx. 74mm / 2.9in Approx. 47mm / 1.9in Approx. 104mm / 4.1in Approx. 35mm / 1.4in Approx. 43mm / 1.7in Size 2: Approx. 125mm / 4.9in Approx. 80mm / 3.1in Approx. 110mm / 4.3in Approx. 28mm / 1.1in Approx. 100mm / 3.9in1 x Module