A52x Series Electronic Refrigeration Controller with Adaptive Defrost Technical Bulletin
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Evaporator Fan Drip-Time Delay
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Evaporator Fan Temperature Delay
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Evaporator Fan Time Delay
When the A52x Controller is in a delay period, the delay type and the minutes left in the delay scroll across the
Message Field at the top of the display.
Anti-Short Cycle Delay
Anti-Short Cycle Delay (ASD) maintains the compressor relay off or open for a period of time after the relay cycles
off. This delay prevents the compressor from cycling back on quickly after it has cycled off. Select from 0 to 12
minutes for the Anti-Short Cycle Delay. See Figure 7.
Figure 7: Anti-Short Cycle Delay (ASD) Overriding Load Demand to Maintain Compressor Relay Off
Evaporator Fan Drip-Time Delay
Evaporator Fan Drip-Time Delay holds the compressor relay and the evaporator fan relays off (open) after the
defrost duration terminates. The user-selected drip-time delay allows the evaporator coil to shed additional water
and reduces the moisture that blows into the refrigerated space when the evaporator fans start. Select from 0 to 10
minutes for the Evaporator Fan Drip-Time Delay after the defrost duration terminates. The Evaporator Fan Drip-
Time Delay is not available for Off Cycle (passive) Defrost. See Figure 8 on page 10.
Evaporator Fan Temperature Delay
Evaporator Fan Temperature Delay holds the evaporator fan relay or relays off (open) after the defrost termination,
drip-time delay, and compressor start in cooling mode. This temperature-based evaporator fan delay allows the
evaporator coil to cool down and freeze any moisture before the evaporator fan or fans start. This delay reduces
the moisture and warm air that is blown into the refrigerated space. Select from 20F° to 35F° for the Evaporator
Fan Temperature Delay. See Figure 8 on page 10.
Evaporator Fan Time Delay
Evaporator Fan Time Delay holds the evaporator fan relays off (open) after defrost termination, drip-time delay, and
compressor restart in cooling mode. This time-based evaporator fan delay allows the evaporator coil to cool down
and freeze any moisture before the evaporator fan or fans start. This delay reduces the water and warm air that is
blown into the refrigerated space. The Evaporator Fan Time Delay works with the Evaporator Fan Temperature
Delay. If the evaporator coil reaches the evaporator fan temperature value before the time delay, the fan turns on. If
the time delay expires first and the coils are not at the temperature value, the fan turns on. Select a time delay from
0 to 15 minutes to allow the evaporator to freeze any remaining moisture, before the evaporator fans turn on.
