Standard Control - Trane CXAO Installation Operation & Maintenance

7.4

Standard Control

Operations description
Compressors oil level check
Inlet temperature check (overheating)
Water circuits fi lling check
Fans and compressors motors electrical input check
Power supply and auxiliary power voltage check
Refrigerant charge check through sight glass
Compressors carter heaters operation check
Tightening all electrical connections
Coils cleanliness
Compressors and liquid circuit solenoid valve check
Adjusting and safety thermostat calibration check
Fans (if present) and compressors contactors state check
Evaporator heater operation check
Motor and fan (if present) bearing noise check
Pressure vessels conditions check
Temperature and pressure probes
The unit comes factory-equipped with all the sensors
listed below. Periodically check that their measurements
are correct by means of sample instruments
(manometers, thermometers); correct readings if
necessary using the microprocessor keyboard. Well-
calibrated sensors ensure better effi ciency for the unit
and a longer lifetime.
Note: refer to the microprocessor use and maintenance
manual for a complete description of applications,
setting and adjustments.
All sensors are preassembled and connected to the
microprocessor. The descriptions of each sensor are
listed below:
Outgoing water temperature sensor – This sensor is
located on the evaporator outgoing water connection
and is used by the microprocessor to control the unit's
load according to the system's thermal load. It also
performs the evaporator's antifreeze protection.
Ingoing water temperature sensor – This sensor is
located on the evaporator ingoing 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 to carry out the
"OAT setpoint override" .
Compressor delivery pressure transducer – This is
installed on every compressor and allows to monitor
the delivery pressure and to control the ventilators.
Should a increase in condensation pressure arise, the
microprocessor will control the compressor load in order
RF-SVX003A-GB
Recommended frequency
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly
Semiannual
Quarterly
Quarterly
Quarterly
Semiannual
Yearly
to allow it to function even if choked. It contributes to
complementing the oil control logic.
Oil pressure transducer - This is installed on every
compressor and allows to monitor the oil pressure.
Using this sensor, the microprocessor informs the
operator on the conditions of the oil fi lter 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 allow to monitor the compressor intake
pressure along with low pressure alarms. It contributes
to complementing the oil control logic.
Intake sensor – This is installed optionally (if the
electronic expansion valve has been requested) on
each compressor, and allows to monitor the intake
temperature. The microprocessor manages the electronic
expansion valve control by means of this sensor.
Compressor discharge temperature sensor – This is
installed on each compressor and allows to monitor
compressor discharge temperature and oil temperature.
The microprocessor controls liquid injection by means
of this sensor and shuts down the compressor in case
of alarm in the event that the discharge temperature
reaches 110°C. It also protects the compressor from
possible overheating with liquid.
Standard Control
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