D-EIMWC01405-18EN- 20/32
The unit controller is a microprocessor control panel designed to perform compressor start up step by step, monitor and
adjust compressor capacity, protecting it, and perform the shutdown sequence in the absence of load or at a set time. The
control panel provides a wide range of data control and registration capacity options. It is important to have good familiarity
with the control system for optimal machine operations. Please note that all units are also provided with the Control Manual.
Fig. 6
– Electrical Panel Layout
3.3
Safeties for each cooling compressor
Motor cooling
High compressor delivery temperature
Compressor suction temperature
Failed start
Low pressure
High pressure
Inverter alarm
3.4
System safeties
Antifreeze
Correct phase sequence and phase failure
Evaporator flow switch
3.5
Regulation type
PID regulation (Proportional - Integrative - Derivative) on the evaporator outlet sensor for perfect water temperature
regulation (
ΔT = ± 0.3° C).
3.6
Compressor Lead-Lag
The water-cooled Daikin EWWD(H)_ DZ units alternate the compressor start sequence (EWWD(H)_DZ dual compressor)
to balance the number of starts and operating hours. Compressors are automatically alternated by the controller.
If the unit is in automatic mode, the compressor with the lowest number of starts is started first. If both compressors are in
operation and one compressor must be turned off, the one with most hours is switched off
3.7
High condensing pressure control
The microprocessor is provided with a transducer to monitor condensing pressure. Although the main purpose of the high
pressure transducer is to maintain proper control of the condensing pressure (by controlling the cooling towers if
connected), another purpose is to send a signal to the microprocessor which stops the compressor in case the discharge
pressure is excessive. If the unit is switched off for high condensing pressure, the microprocessor must be reset manually.
General
door
locking
switch handle
User interface
Emergency button
Switches: Unit On/Off
