Surge Absorber @ surge Arrester ??

[azril83]

Hi Guys,
Can anybody explain how does this surge absorber operate for motor starting circuit. Please refer to the attached graph for reference. i have been told that this surge absorber is used for increase back the current when it slowly decrease below its rated current. So, there is 3 steps before the current reach its rated current. can anybody explain?

 

[bacon4life]

Perhaps it is resistor motor starting as explained on page 4 of the link below.

The voltage drop across the resistor adds to the back emf the motor creates, which results in limiting the current. As the motor gets up to speed, the internal voltage increases so the external resistors are bypassed.

http://www.cumminspower.com/

http://www/literature/applicationmanuals/t-030_p159-164.pdf