Frequency Control - Mitsubishi Electric PURY-M200YNW-A1 Service Handbook

[5-2 Outdoor Unit Control ]
5-2-5

Frequency Control

Depending on the capacity required, the frequency of the compressor is controlled to keep constant evaporation temperature
(0°C [32°F] = 0.71 MPa [103 psi]) during cooling operation, and condensing temperature (49°C [120°F] = 2.88 MPa [418 psi])
during heating operation.
The table below summarizes the operating frequency ranges of the inverter compressor during normal operation.
Model
M200
M250
M300
M350
M400
M450
M500
EM200
EM250
EM300
EM350
EM400
EM450
EM500
The maximum frequency during heating operation depends on the outside air temperature and the dipswitch settings.
(1) Pressure limit
The upper limit of high pressure (63HS1) is preset, and when it exceeds the upper limit, the frequency is decreased every 15
seconds.
The actuation pressure is when the high-pressure reading on 63HS1 is 3.58MPa[519psi].
(2) Discharge temperature limit
Discharge temperature (TH4) of the compressor in operation is monitored, and when it exceeds the upper limit, the frequency
is decreased every minute.
Operating temperature is 110°C [230°F].
(3) Periodic frequency control
Frequency control other than the ones performed at start-up, upon status change, and for protection is called periodic frequen-
cy control (convergent control) and is performed in the following manner.
Periodic control cycle
Periodic control is performed after the following time has passed
30 seconds after either compressor start-up or the completion of defrost operation
30 seconds after frequency control based on discharge temperature or pressure limit
The amount of frequency change
The amount of frequency change is controlled to approximate the target value based on the evaporation temperature (Te) and
condensing temperature (Tc).
BS_05_M
Frequency/cooling
Max Min
52Hz 18Hz
65Hz 18Hz
74Hz 18Hz
95Hz 18Hz
97Hz 37Hz
111Hz 37Hz
120Hz 37Hz
52Hz 18Hz
65Hz 18Hz
74Hz 18Hz
95Hz 18Hz
97Hz 37Hz
111Hz 37Hz
120Hz 37Hz
Frequency/heating
Max Min
58Hz 18Hz
74Hz 18Hz
92Hz 18Hz
107Hz 18Hz
113Hz 37Hz
124Hz 37Hz
140Hz 37Hz
58Hz 18Hz
74Hz 18Hz
92Hz 18Hz
107Hz 18Hz
113Hz 37Hz
124Hz 37Hz
140Hz 37Hz
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