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83•dap4UserManual

e) Ifdehumidicationisprogrammedfor“1Cinlimit”or“2Cinlimit”thedehumidication

cooling will be inhibited by reheat if the return air temperature drops below Temperature

 Setpoint-TemperatureDB-2degF.Dehumidicationwillbeinhibiteduntilthereturnair

temperature rises above the Temperature Setpoint. Compressor short-cycle time will not

be violated.

f) Ifdehumidicationisprogrammedfor“1CNoLimit”or“2CNoLimit”,dehumidication 

 remainsonuntilthehumiditysetpointisreached.Inthismode,dehumidicationhas

priority and overcooling is disregarded. The reheat sequence will remain the same.

g) Thereisaone(1)minutedelaybetweenstop-to-startofdehumidicationcooling.

Compressor short-cycle time delay will not be violated.

h) Thereisave(5)minutedelaybetweendehumidicationandhumidication.

i) Relative humidity control mode is not recommended for discharge temperature control,

Dewpoint control method should be used in this case.

j) Thecompressorstagingsequencefordehumidicationcoolingisasfollows:

A. Relative humidity control mode:

a) Single Variable speed compressor system

 Dehumidicationcycleson

-- If unit is not in cooling mode, the variable speed compressor turns on when humidity

is at Humidity Setpoint (HSP) + Humidity Deadband (HDB).

Compressor will modulate its speed from 0% to 100% in 1%RH above Humidity

Setpoint +Humidity DB. For instance:

If Humidity = Humdity Setpoint + Hum Deadband, VFD will run at 0VDC

If Humidity = Humdity Setpoint + Hum Deadband + 0.1%, VFD will run at 10%

If Humidity = Humdity Setpoint + Hum Deadband + 0.2%, VFD will run at 20% Etc.

 -- Ifcoolingrequiresduringdehumidicationcycleanddehumidicationmodeisset

  to“1Cinlimit”thetemperaturecoolingcontrolwilloverridethedehumidication

  coolingcontrol.Ifdehumidicationmodeissetto“1CNolimit”,unitwillcontinueto

  nishthedehumidicationcyclethenswitchtotemperaturecontrolcoolingmode.

 Dehumidicationcyclesoff

-- Variable speed compressor C1 starts to ramp down in 0.1 % RH decrement when

Humidity drops to Humdity Setpoint + 1%. Compressor decreases 10% speed for

each 0.1%RH.

-- When Humidity equals Humdity Setpoint, compressor runs at its minimum speed

(0 VDC).

-- When Humidity is at Humidity Setpoint – 0.5 % and compressor minimum runtime

  expired,compressorturnsoff(NO2startsignalturnsoff).

b) DualDXcircuitwithavariablespeedcompressorandaxedspeedcompressor

Data Aire dap 4 User Manual

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