Reading Surge Ratings for Flyback Diodes

Thread Starter


Joined Nov 1, 2010

I am struggling with reading diode specs.
I have a system with a large 36 V DC motor that has a peak inrush current (worst case) current of 250 A. Inrush current limiting has reduces this to less than 180 A.

Given certain mechanical conditions the motor can trigger an over current event in the power supply, causing it to shut down. The motor then dumps the stored energy back into the power system, and causes the polarity to reverse causing issues.

I want to add a flyback diode to prevent this, but would appreciate some pointers on how to select a proper rating for the diode.
I see that many diodes rate their allowable "surge" currents in half sine waves at 50 Hz, and the number of repetitive cycles.

First of all, how do I relate that rating to DC?

Any help is much appreciated!