Function PACD011001C2
258 Function Urban Multi “MX1R, ME1R Series” Using R-407C
1.14 Control During Low Outdoor Air Temperature Cooling
When the outdoor air temperature is low in cooling operation, outdoor unit fans, electronic expansion valve
and compressors are controlled as follows in order to primarily maintain high pressure and to protect drop
in refrigerant circulation caused by drop in high pressure.
CU-5
CU-8·10
Note:
Step No. changes according to high pressure, low pressure and frequency.
(Step No. increases with reduction of high and low pressure.)
Low Outdoor Air Cooling in Conditions (Steps 1-1, 2, 3)
Operating status Electronic expansion valve Fan Frequency (Hz)
Normal operation Fully open H Changes according to operating
status
Low outdoor temperature
cooling operation
Step 1 Fully open L 76
Step 2 Fully open OFF 48
Operating status Electronic expansion valve Fan Frequency (Hz)
M1F M2F 8K 10K
Normal operation Fully open H ON Changes according to operating
status
Low outdoor temperature
cooling operation
Step 1-1 Fully open L ON 96 116
Step 1-2 Fully open H OFF 86 106
Step 1-3 Fully open L OFF 76 96
Step 2 Fully open OFF OFF 62 76
Normal operation
Step 1-1
Step 1-2
«
carried out 30
continuous
seconds
«
carried out 30
continuous
seconds
¥ carried out 30
continuous
seconds
Step 1-3
¥ carried out 30
continuous
seconds
• Cooling with compressor running
(doesn't include oil return)
&
• High pressure < 10 kg/cm² (0.98MPa)
• EV = 2000 pulses
(completely open)
or
• High pressure > 15.2 kg/cm²
(1.489 MPa)
• Compressor off
or
• Other than cooling
(includes oil return)
or
• High pressure < 22 kg/cm²
(2.156 MPa)
Conditions satisfied
(M017)
«
¥