PWM change causes issue

[dgunawan]

On my 600/12S bird, I use a Scorpion HK3-4025-550, YGE 90HV, iKon FBL, & external BEC Gryphon Quasar Hyper GSR-7075 LMT.

This past weekend I wanted to change my PWM setting on the esc and monitor the temp differences on the esc, lipos, & motor. I've flown 21 flights with 8 kHz, Scorpion's recommended value as found on their website. In some posts, people talked about using a formula to figure the PWM value: Kv x Volts (nominal you are using) x Pole count / 20. So I did the math too: 550 x 44.4 x 10/20 = 12210, or rounded down, 12 kHz.

First flight with 12 kHz seems fine. Second flight, during spool up the motor tried to spin but then stopped, giving 6 beeps for my esc indicating failed startup. Disconnected/reconnected main & Rx lipos, 2nd try, same thing. 3rd try, no power out of my BEC. It doesn't even turn on.

Then I used an unregulated 2S lipo. With 12 kHz, same issue. I finally changed the PWM back to 8 kHz, and everything is peachy.

Anyone has similar issue?