Is this an Evolution controller?
If so, there have been quite a few firmware updates and it probably is a couple behind.
What's the LRA of the cooler?
Yes it is the evolution controller. Last update was about 6 months ago.
The cooler is only a fan and does not have a LRA as a fan. The motor draws only 7 amps running on low and that typically means about 14 amps on start up. That should not cause a significant drop in Hz. I think it's something to do with the electroncs in the low voltage controls.