Available Sensors; Pressure Transducers; Temperature Sensors; Thermistors - Daikin EWWQ-G Operation Manual

EWWQ090G ÷ EWWQ720L - R410A - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410A - Condenser less
EWHQ100G ÷ EWHQ400G - R410A - Heat pump scroll chillers
EWAQ- - R410A - Air-cooled scroll chillers
EWAQ- - R410A - Air-cooled scroll chillers
EWYQ- - R410A - Air-cooled scroll heat pumps
again. The alarm must be reset on the switch itself and on the Unit Controller. The triggering
pressure value cannot be changed.

Relief Safety Valve
If the pressure becomes too high in the refrigerant circuit, the relief valve will open to limit the
maximum pressure. If this happens switch off immediately the machine and contact your local
service organization.

1.4 Available sensors

1.4.1 Pressure transducers

Two electronic sensors are used to measure the evaporating and condensing pressure of each
circuit. The range of each sensor is clearly indicated on the sensor casing.

1.4.2 Temperature sensors

The evaporator and condenser water sensors are installed in the entering and leaving side.
Additionally each circuit installs a suction temperature sensor to monitor and control the
superheated refrigerant temperatures.

1.4.3 Thermistors

Each compressor is equipped with PTC thermistors which are immersed into motor windings for
motor protection. Thermistors trip to a high value in case the motor temperature reaches a
hazardous temperature.

1.5 Available Controls

In the following the different functions will be distinguished between Water Cooled (W/C) and Air
Cooled (A/C) units and Cooling Only (C/O) and Heat Pumps (H/P). If not specified one specific
function can apply to any W/C unit independently from being a C/O or H/P unit.

1.5.1 Evaporator - Condenser pumps

The controller can regulate one or two evaporator pumps and takes care of automatic change-over
between pumps. It's also possible to prioritize the pumps and temporarily disable one of the twos.
The controller can also regulate an unique condenser water pump (W/C units only).

1.5.2 Compressors

The controller can regulate two or four compressors installed on one or two independent refrigerant
circuit. All the safeties of each compressor will be managed by the

1.5.3 Expansion Valve

The controller can regulate an electronic expansion valve per each refrigerant circuit to guarantee
the best operation for the refrigerant circuit.

1.5.4 Four Way Valve

The controller can command a four way valve per each refrigerant circuit where required. The
valve is used to reverse the unit mode from Cool to Heat.
EWWQ - EWLQ - EWHQ
EWAQ - EWYQ
Air or Water cooled scroll chiller &
heat pump
D-EOMHW00107-15EN
Air and Water cooled scroll chillers & heat pump
controller.
Operation Manual
Operation
Manual
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