evaporator fan behavior with the evaporator fan delay-after-defrost feature. The delay time period
is 0 min to 15 min. This feature does not apply if the controller is set to an off-cycle defrost.
Adaptive defrost setup parameters
The following sections provide details about paramaters that are available if you select adaptive
defrost.
Expected defrost duration
The expected defrost duration is the estimated time it takes to fully defrost the evaporator coil
and reach the defrost termination temperature. When you set up the adaptive defrost feature, you
enter the number of minutes for the expected defrost duration. During operation and changing
load conditions, actual defrost durations may vary in length from your defined expected defrost
duration. When this occurs, the system adjusts the defrost schedule.
Defrost interval
The defrost interval is an estimate of the number of hours between the start of consecutive defrost
cycles. You enter the expected defrost interval time in hours for the first defrost interval. The
adaptive defrost feature shortens or lengthens the defrost interval to reach the defrost termination
temperature in the expected defrost duration. This value provides a starting point for the adaptive
defrost algorithm. If the system reaches the defrost termination temperature before the expected
defrost duration elapses, adaptive defrost lengthens the next defrost interval. If the system reaches
the defrost termination temperature after the expected defrost duration time elapses, adaptive
defrost shortens the next defrost interval.
Maximum time between defrosts
Maximum time between defrosts defines the maximum number of hours for any adaptive defrost
interval. If the system calculates a defrost interval that is greater than your defined maximum time,
the controller ignores the calculation and starts the next defrost duration at your defined maximum
time.
Minimum time between defrosts
Minimum time between defrosts defines the minimum number of hours for any adaptive defrost
interval. If the system calculates a defrost interval that is less than your defined minimum time, the
controller ignores the calculation and starts the next defrost duration at your defined minimum
time.
Blackout period
You can schedule a daily blackout period for adaptive defrost applications. This schedule prevents
the occurrence of defrost cycles during the defined blackout period. Blackout periods are typically
scheduled for a regular, predictable period of high cooling demand. To establish a blackout period
for adaptive defrost, set up the blackout start time and blackout parameters in the defrost setup
menu flow.
• Blackout start time: This time is when the blackout period begins. The adaptive defrost
algorithm does not schedule any defrosts from the start to the end of the blackout period.
Edit the real-time value to the time at which the blackout period starts. The real-time value
depends on the time format type selected in the time and date screens in the system setup
menu flow.
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MR5 Series Panel Mount Case Controller Technical Bulletin
Discontinued
