Trane Thermo King Magnum Plus Operator's Manual page 15

SPECIFICATIONS
MP-4000 CONTROLLER SPECIFICATIONS (CONTINUED)
Chilled Mode (continued)
Frozen mode
Reset to Base Time
Defrost Termination:
Defrost (Coil) Sensor
Termination Timer
Power Off
12
There is an interval set for defrosting, however, the defrost timer is built intelligent - it
detects whether or not there is ice building up on the coil. If there is no ice building up
on the coil, it extends the defrost interval, and if there is Ice building up earlier on the
coil it reduces the defrost interval. The maximum interval is 48 hours.
Every 8 hours of compressor operation. Defrost interval increases 2 hours each
timed defrost interval. Maximum time interval in Frozen mode is 24 hours.
Defrost timer resets if the unit is off more than 12 hours, setpoint is changed more
than 5 C (9 F) or PTI pretrip test occurs.
Chilled mode: Terminates defrost when coil sensor temperature rises to 18 C (65 F).
Frozen mode: Terminates defrost when coil sensor temperature rises to 18 C (65 F).
Terminates defrost after 90 minutes at 60 HZ operation if coil sensor has not
terminated defrost (120 minutes at 50 Hz operation)
Turning Unit On/Off switch Off terminates defrost