IOM – FLEXY II – 1007 – E Page 91
REFRIGERATION
FAULT POSSIBLE CAUSE AND SYMPTO MS SOLUTION
Meas ure t he s uperheat and s ub-cooling:
Good if 5° C <SC <10° C a n d 5 °C <SH <1 0°C
Bad if SC>10°C and SH too Low Refrigerant charge too low
Check superheat adjustment and charge unit (a
leak check must be carried out)
In Heat Pump Mode the temperature difference
between T outdoor and Tev ap. (Dew) is too high
5°C < Delta T < 10°C excellent
10°C < Delta T < 15°C acceptable
15°C < Delta T < 25°C too high
If too high c hec k the coils are clean or check coil
internal pressure drop between the liquid line and
the suction line
Good if < 3bar
Too high if > 3bar (coil bloc k ed)
Refrigeration circuit blocked in distribution
Stop the f an and create icing of the coil.
Check all circuits freeze evenly across the whole
surface of the coil
If som e parts of t he c oil do not f reeze this c ould
indicate a problem with the distribution
Liquid line drier blocked. High temperature
difference between inlet and outlet of the drier
Change f ilter drier
Contaminant in the expansion valve
Attempt to free the valv e adjusting element by
freezing the valv e and then heating the
thermostatic element. Replace the v alve if
necessary
Expansion valv e not adjusted properly Adjust the expansion Valv e
Ice plug in the expansion v alve.
Heat the main body of the valve. If the LP
increases and then decreases gradually, empty
the circuit and replace the drier.
Incorrect insulation of the thermostatic bulb of
the expansion valv e
Superheat too low: adjust superheat
Mov e t he therm os t at ic elem ent along the pipe
Insulate the Thermostatic element of the valve
Low Pressure Switch cut out point too high
Check the cut out pressure of the Low Pressure
switch: It must be 0.7+/- 0.2bar and must closes
at 2.24 +/- 0.2 bar
LP PROBLEMS and
LP CUT OUTS
LP cut out due to not enough def rost on heat
pumps
Adjust the CLIMATIC settings to extend the
def rost cycles or shorten the time between
def rosts
Incorrect Airflow rates
Heat pump mode:
Check the filter before the indoor coil
measure and estimate the airflow rate
increase the speed of the fan
Cooling mode:
Check the condenser fan (Amps)
HP PROBLEMS AND
HP CUT OUTS
Mois t ure or c ont am inants in t he system
Summer operation
Sev eral hours after the unit has stopped, check
the correspondence between the measured
pressure and the outdoor temperature
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