ESIE15-13B
Troubleshooting by Remote Controller
Service Diagnosis
195
Check for Inadequate Refrigerant
As criteria for judging whether refrigerant is inadequate or not, refer to the following operating conditions.
<Diagnosis of inadequate refrigerant>
In cooling operation
(1) As suction superheat degree increases due to refrigerant shortage, the electronic expansion valve tends
to open (opens fully) in order to avoid overheat operation.
(2) In response to decreased evaporator capacity caused by refrigerant shortage, capacity is controlled in the
inverter in order to maintain low pressure, which results in a decrease in frequency.
(3) Because of (1) and (2) above, the compressor frequency decreases despite a large difference (large load)
between temperature set by the remote controller and indoor suction temperature, resulting that cooling
capacity becomes unavailable.
(4) If refrigerant shortage worsens, the electronic expansion valve remains fully open and suction superheat
degree further increases. In addition, because the compressor frequency drops to the level of the lowest
frequency (52 Hz) and the refrigerant flow rate decrease, low pressure cannot be maintained.
*3 This measured temperature is used to calculate the equivalent saturation pressure of the
refrigerant.
(Refer to P.200.)
CHECK 10
Cooling
*1
High Pressure
Intermediate heat
exchanger
thermistor (*3)
*2
Low Pressure
Pressure sensor
Cooling
Suction superheat degree
Compressor frequency
Electronic expansion valve
Adequate level
As compressor frequency
decreases, high pressure
decreases.
(Maintains a certain
level of low pressure)
Actual high
pressure
When the refrigerant flow rate
decrease, it is impossible to
maintain a low pressure.
As the electronic expansion valve
opening degree reaches the maximum,
suction superheat degree increases.
Inadequate
In response to decreased evaporator capacity
caused by refrigerant shortage, capacity is
controlled in the inverter in order to maintain a low
pressure, which resulting in a decrease in frequency.
Avoid overheat operation by
changing SH target value
(Degree of inadequate refrigerant)
High pressure
(
∗
1)
Low pressure
(
∗
2)
Abnormal refrigerant
shortage
The maximum opening degree of the
electronic expansion valve (480 pulses)
Refrigerant
shortage warning
Reaches the lowest frequency
Summary of Contents for GQI-Eco Series
Page 2: ......
Page 6: ...ESIE15 13B iv Table of Contents...
Page 14: ...Introduction ESIE15 13B xii...
Page 18: ...Outlook Outdoor Units ESIE15 13B 4 General Information 2 Outlook Outdoor Units...
Page 22: ...Operating range ESIE15 13B 8 General Information...
Page 108: ...Emergency Operation ESIE15 13B 94 Field Setting...
