Daikin EWADC12C-XL [300/304] Standard checks

Maintenance ESIE10-01

5–10 Part 5 – Maintenance

1.3 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) and

correct any wrong readings as necessary, using the microprocessor keypad. Well-calibrated sensors

guarantee greater machine efficiency and a longer life.

N.B.: refer to the microprocessor use and maintenance manual for a complete description of the

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 for the monitoring of the external

air temperature on the microprocessor display. It is also used to carry out the 'OAT setpoint

override'.

■ Compressor discharge pressure compressor – 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 split. It also contributes to the oil control logic.

■ Oil pressure transducer – This is installed on every compressor and allows you 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 compressor – This is installed on every compressor and allows to monitor the

compressor suction pressure along with the low pressure alarms. It also contributes to the oil

control logic.

■ Suction sensor – This is installed optionally (if the electronic expansion valve has been

requested) on every compressor, and allows for the monitoring of suction temperature. The

microprocessor uses the signal from this sensor to control the electronic expansion valve.

■ Compressor discharge temperature sensor – This is installed on every compressor and allows

to monitor the compressor discharge pressure along with the oil temperature. The microprocessor

uses the signal from this sensor to control liquid injection and shut down the compressor should

discharge temperature reach 110°C. It also protects the compressor from pumping liquid at

start-up.