Thermal Shutdown

Hi,

We have a doubt regarding thermal shutdown of an IPM. We are using Hitachi ECN30624PN IPM. As per datasheet, the maximum junction temperature of the IPM is 160 deg C. My doubt is that when does the IPM undergo thermal shutdown mode?

Also, when we are using the same IPM for BLDC motor controller, when the motor is rotating in clockwise direction, the IPM is going to shut down mode very fastly. Is this the thermal shutdown or overcurrent protection mode?

The controller is designed such that the motor should rotate in anticlock wise direction. So, when the direction of rotation of the motor changes, does the current drawn by the motor changes? Does the IPM gets heated faster in this case?

Kindly reply please.