Standard Checks; Temperature And Pressure Sensors - Daikin EWYD-BZ Series Installation, Maintenance & Operation Manual

Standard checks

Temperature and pressure sensors

The unit comes factory-equipped with all the sensors listed below. Periodically check that their measurements are correct
by means of reference instruments (manometers, thermometers); correct the wrong readings as necessary using the
microprocessor keypad. Well-calibrated sensors ensure better efficiency for the machine and a longer lifetime.
Note: refer to the microprocessor use and maintenance manual for a complete description of applications, settings and
adjustments.
All sensors are preassembled and connected to the microprocessor. The descriptions of each sensor are listed below:
Outlet water temperature sensor – This sensor is located on the evaporator outlet water connection and is used by the
microprocessor to control the machine load depending on the system's thermal load. It also helps control the
evaporator's antifreeze protection.
Inlet water temperature sensor – This sensor is located on the evaporator inlet water connection and is used for
monitoring the return water temperature.
External air temperature sensor – Optional. This sensor allows to monitor the external air temperature on the
microprocessor display. It is also used in the "OAT setpoint override".
Compressor discharge pressure transducer – This is installed on every compressor and allows to monitor the
discharge pressure and to control the fans. Should the condensation pressure increase, the microprocessor will control
the compressor load in order to allow it to function even if the compressor gas flow must be reduced. It also contributes
to the oil control logic.
Oil pressure transducer - This is installed on every compressor and allows to monitor the oil pressure. The
microprocessor uses this sensor to inform the operator on the conditions of the oil filter and on how the lubrication
system is functioning. By working together with the high- and low-pressure transducers, it protects the compressor from
problems deriving from poor lubrication.
Low-pressure transducer – This is installed on every compressor and allows to monitor the compressor suction
pressure along with low pressure alarms. It contributes to complementing the oil control logic.
Suction sensor – This is installed on each compressor and allows to monitor the suction temperature. The
microprocessor uses the signal from this sensor to control the electronic expansion valve.
Compressor discharge temperature sensor – This is installed on each compressor and allows to monitor compressor
discharge temperature and oil temperature. The microprocessor uses the signal from this sensor to control the liquid
injection and to shut down the compressor in case that the discharge temperature reaches 110°C. It also protects the
compressor from pumping liquid refrigerant at start-up.
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