I just wanted to know if in a BLDC motor i am driving and in the initial phase of testing may be i want to try with different switching. In case my switching is wrong and the machine halts or moves back and forth. In these circumstances it is always that mosfet fails, if in case i don't stop switching within some time. I know there is no schematic. But can you please tell from experience.
For testing it is usual to use large IGBT's instead of mosfets - so that if you get it wrong, the IGBT's can blow a fuse or similar and you don't have to replace them on your test rig - which should have PLENTY..! of heatsinking to allow the IGBT's to dissipate heat for short term analysis when you have it wrong.
Choose a 600V 50A or larger IGBT and move to fets when you have all the kinks out of the switching control...