14.0 Mini Dap4 Control Logic - Data Aire Mini dap4 Installation, Operation & Maintenance Manual

14.0 Mini dap4 CONTROL LOGIC

SYSTEM START DELAY
After the self-test is complete, the Timed Start Delay will be displayed and will start counting down from the pro-
grammed delay. The factory setting is five (5) seconds. The setting is programmed in Menu A – ON/OFF. The range
is from 1 to 600 seconds in 5 second increments.
BLOWER
Centrifugal Fans – The blower(s) will start upon completion of the Timed Start Delay and is programmed and wired to
run continuously during unit operation.
FUNCTIONS
Cooling, reheat, humidification and dehumidification functions are inhibited for one (1) minute after the blower starts.
This allows the temperature and humidity sensors to adjust.
COMPRESSOR COOLING
1. There is a five (5) minute delay between start-to-start of the same primary stage compressor. The delay will be
increased to six (6) minutes for one (1) hour following the detection of a compressor short-cycle condition even if
the compressor short cycle alarm is disabled (Menu K - Alarms and Limits).
2. There is a two (2) minute delay between stop-to-start of the same primary stage compressor.
3. There is a one (1) minute delay between stop-to-start of the same secondary unloader stage compressor or stop-
to-start of a second secondary stage compressor (dual compressor LCS type units only).
4. Compressor staging sequence at each adjustment period:
*LCS models with dual compressors (dual stage)
CHILLED WATER COOLING
(Standard) Chilled water valve "opening" sequence (Increasing Temperature): The chilled water is a two-position
valve that will open on a call for cooling in following sequence:
Valve ON when Current Temperature = Setpoint + Deadband
Valve OFF when Current Temperature = Setpoint
(Optional Modulating CW Valve) Chilled water valve "opening" sequence (Increasing Temperature)
1. The chilled water valve proportionally opens 10% for each 0.1°F above the temperature setpoint plus temperature
deadband.
43 • Mini dap4 User Manual
UNITS WITH STANDARD (DUAL) SCROLL COMPRESSORS
Compressor "ON" sequence (Increasing Temperature)
Cool 1 ON at Temperature Setpoint + Temperature Deadband
Cool 2 ON at Temperature Setpoint + Temperature Deadband + 0.3°F*
Compressor "OFF" sequence (Decreasing Temperature)
Cool 2 OFF at Temperature Setpoint + 0.3°F*
Cool 1 OFF at Temperature Setpoint