0F is the lowest setpoint you can have.
Trane has 6 menus in the controller. the other 2 menus are "hidden" and you need the password to access it. Trane hid it really well...in the IOM on page 93...duh!
i think that you may have some inaccurate sensors (sat evap temp and/or comp temp sensor), so i would check them against a well known thermocouple. but like i said earlier, get those values and get your glycol levels up.
74: Run Normal
7E: Run Unload
77: Run Evap Limit
the chiller will run to maintain the load until the "saturated evap temp" hits the number programmed into menu #41. it will then unload (code 77) to maintain the "saturated evap temp" above its minimum setpoint (menu #41). at this point you will start losing your load.