Low duty cycle issues

Hi All,

Im currently in the process of trying to run a brushless compressor to chill water. We replaced the original ESC that was supplied, as it was a locked down oem unit, that wasnt suitable for various reasons. After doing so, we seemed to have picked up an issue.

Mostly at low duty cycles (25-30%) the motor seems very unstable, and on occasion will try and draw up to the limits set in the software. Around this range, it will also intermittently seem to stop and start making a high pitched squeal.

If anyone has seen something like this before, or where I should start as far as changing some settings, it would be greatly appreciated.

Regards,
Nathan