Data Aire dap 4 User Manual

82•dap4UserManual
 3. TheEnergySaver/AuxiliaryChilledWaterCoolinglogicwillbethesameasthe 
chilled water cooling logic of the discharge air temperature control, this means dap4
uses a preset PID loop to control the CW valve to maintain a discharge air
temperature setpoint.
4. Low discharge temperature alarm limit must be set in menu K-Alarms & Limits. If
Discharge temperature drops below this limit, compressors will be inhibited for at
least 15 minutes and discharge temperature rises above this limit.
5. If discharge temperature drops below the limit while the variable speed compressor
  nishingitsminimumruntimetheCWshouldcloseuntildischargetemperaturerises
above the limit.
6. The following is the compressor staging sequence.
Compressors on cycle with energy saver
-- Variable speed compressor C1 comes on at Temperature Setpoint + temperature
deadband + STS band. Once variable speed compressor comes on it will use PID
logic to maintain temperature setpoint + 1Deg F (to make sure CW is fully utilized).
 -- FixedspeedcompressorC2(*)comesonatTemperatureSetpoint+Temperature
Deadband + 1°F + STS DB and variable speed compressor C1 has operated at
95% for at least the C2 on delay. When C2 comes on, variable speed compressor
C1 will drop its speed to minimum speed for a delay modulation period.
Compressors off cycle during energy saver mode
 -- Fixedspeedcompressorc2(*)cyclesoffatTemperatureSetpoint+STSDBfora
C2 off delay duration and variable speed compressor C1 runs at 100% .
-- Variable speed compressor C1 cycles off at Temperature Setpoint Compressor will
not violate its minimum runtime and short cycle regulation.
* This applies on dual compressor system.
3. Dehumidication mode
Dehumidicationiscontrolledbasedonreturnairconditionsandhasvecontrolmodes:None,
1C In limit (one compressor within reheat limit), 1C No limit (one compressor without reheat limit),
2C In limit (two compressors within reheat limit) and 2C No Limit (two compressors without reheat
limits).
a) Therearethreedehumidicationcontrolmodesforsinglecompressorunit:None,1Cin
limit and 1C No limit.
b) Therearevedehumidicationcontrolmodesfordualcompressorsunit.
c) Reheatisrequiredfordehumidication.
d) Dehumidicationcoolingcanbecontrolledbyrelativehumidityand/ordewpoint.

Data Aire dap 4 Specifications

General

Brand	Data Aire
Model	dap 4
Category	Control Unit
Language	English