Possible Problems At Commissioning; Operational Checks - Carrier 50FF 020-093 Installation, Operation And Maintenance Instructions

13 - COMMISSIONING
Control of the refrigerant charge
■ Each unit is shipped with an exact charge of refrigerant for
proper operation.Refrigerants available are: R-410A or R-454B.
Important: the type of refrigerant included in the unit can be
consulted on the name plate, see section 4.3.
■ To make sure that the unit is fi lled with the correct charge of
refrigerant, check the values of overheating and subcooling,
circuit by circuit, with the system running at full capacity.
If the refrigerant charge is lower than required, the suction
pressure will drop and overheating on the compressor inlets
will be high. This can cause an interruption in operation due to
activation of the refrigerant charge safety device.
To adjust the refrigerant charge, each circuit has a schrader-
type valve in the liquid line, before the dryer fi lter.
■ Verify the absence of any leaks of the refrigerant. In case of
a leak:
- Completely drain the refrigerant charge using a specifi c
recovery machine for the type of refrigerant included in the
unit (R-410A or R-454B). Repair the leak.
Important: Always follow the recommendations given in
section 2.2 "Safety standards for refrigerant".
- Next, reload the refrigerant into the unit according to charge
data provided in a table of the chapter on "Maintenance" and
in the unit's name plate.
- Add the refrigerant via the charging valve, located in the
liquid line, using the appropriate equipment and tools, with
the compressors stopped, monitoring the pressures to control
any anomaly.

13.2 - Possible problems at commissioning

All indications given in this manual must be respected and
complied with to guarantee a correct operation of the units.
Next, several possible operation problems are stated which could
happen if the conditions of the commissioning are not appropriate.
■ Air fl ow lack: very high diff erences between inlet and outlet
temperatures, originated by a high pressure drop in the ducts,
or by other causes that impede the correct circulation.
■ Air recirculation in the unit, originated by some obstacle in the
air aspiration or outlet.
■ Noise problems because of excessive air fl ow in the grille.
■ Water overflowing to the pan problems, originated by an
excessive fl ow, an incorrect siphon installation or because a
defective unit level.
■ Refrigerant circuit humidity problem, because of an incorrect
vacuum realization.
Charging valve

13.3 - Operational checks

Check the unit operation by verifying the electronic control and
the safety devices.
■ It is also recommendable to create a report, taking note of the
date, which includes the following information:
- the nominal voltage;
- current absorbed by the compressors, fans and other
electrical components;
- signifi cant temperatures in the cooling circuit (see attached
table);
- other aspects considered interesting such as alarms detected
by the electronic control of the unit.
The recording of these parameters whilst the unit is running
allows controlling the installation performance and it is the
best possible way to avoid breakdowns since the analysis of
these data makes early detection of anomalies possible or the
provision of the necessary means available to ensure that they
do not take place.
Operating readings
Cooling MODE
Suction pressure
Suction temperature (1)
Compressor
Condensation pressure
Condensation temperature (2)
Gas inlet temperature
Liquid outlet temperature (3)
Air
Air inlet temperature
condenser
Outdoor temperature
Air outlet temperature
Air inlet temperature
Air outlet temperature
Air
evaporator
Liquid inlet temperature
Evaporation outlet temperature (4) ºC
Subcooling (2) - (3)
Overheating (4) - (1)
Heating MODE
Suction pressure
Suction temperature (1)
Compressor
Condensation pressure
Condensation temperature (2)
Liquid inlet temperature
Gas outlet temperature (4)
Air
Air inlet temperature
evaporator
Outdoor temperature
Air outlet temperature
Air inlet temperature
Air outlet temperature
Air
condenser
Gas inlet temperature
Liquid outlet temperature (3)
Subcooling (2) - (3)
Overheating (4) - (1)
bar
ºC
bar
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
bar
ºC
bar
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
ºC
67