My bad - I did not appreciate your issue was with the EMS control board, and not the HH control board.
I am learning about my EMS system right now, as I have an intermittent flip from 50A to 30/20 amp service on my EMS while on generator power; it should be constant on 50A from my newby knowledge.
I found an online manual for my
Intellitec Model 800; maybe it is similar to yours and may provide some help?
Hope the helps,
Brian