Motor Soft Starter Protection Functions

We make our motor soft starters have all kinds of protection functions to protect the safety of the soft starter and the motor. You can choose the correct protection Class and parameters according to your application conditions.

Over-Heat Protection: When soft starter inner temperature is up to 80℃±5℃, the soft starter will turn to Over-Heat protection, when be down to 55℃, this protection removes.

Input default phase protection: delayed time < 3s

Output default-phase protection: delayed time < 3s

Three-phase unbalance protection: delayed time < 3s, when the current among three phrases is more than 50%±10%, the protection will be valid.

Starting overcurrent protection time: The diagram of over current 5 times of set rated working current curve diagram like:


Working over-load protection time: the starter will be in inverse time thermal protection on. Base of the Max working current of motor, (show on above diagram)

Low voltage protection delay time: When power voltage is less than 40%, the protection delayed time < 0.5S; When power voltage is less than 80%, the protection delayed time < 3S.

Over-voltage protection delay time: When power voltage is more than 130%, the protection delayed time < 0.5S; When power voltage is more than 120%, the protection delayed time < 3S.

Load short-circuit protection delay time: The protection delayed time < 0.1S.

Motor underload protection delay time: The protection range (10% - 90%) is set by PU, the delayed time is 5 seconds. When PU < 10, the protection is invalid.