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If you are using an external bypass soft starter, you will encounter a situation where the soft starter cannot switch the bypass. Why is this? How can I resolve this situation?

The external bypass soft starter is the most stable soft starter because the operating current is switched to the bypass AC contactor after the boot process is complete. The soft starter itself is only responsible for monitoring and fault control, so its durability is also at its best and can be used for years without failure.

Why Soft Starter Doesn't Switch Bypass:

1. Start in voltage mode and set the start time. When the start time is reached, the motor will switch regardless of whether the motor starts normally. When it happens that the motor current reaches its maximum, the load on the AC contactor when opening and closing becomes very large, an arc is drawn, and in the worst case, the contactor burns out. The general situation is that there is a voltage drop at the start of the motor, which can cause the voltage to drop too low, or the bypass contactor voltage is not sufficient during switching, resulting in poor contact and affecting normal start. ..

The solution is:

A. Extend the startup time, such as changing his default 16 seconds to his 30 seconds.

B. Change the boot mode and use the current limit boot mode to limit the current to within 300% or 400% of the rated current. The process of starting the soft starter in current limit mode is that the current slowly increases from 0 after pressing the start button and does not increase after reaching the limit. Speed, current below rated current, bypass contactor Turns on and switches to complete the boot process.