Mitsubishi Electric City Multi PFAV-P500VMH-E, Руководство по обслуживанию

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VIII
Control ]
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HWE07150 GB
-6- Compressor Frequency Control
ΠThe evaporation temperature is varied during cooling operation and the condensing temperature is varied during heating op-
eration depending on the capacity required.
ΠThe table below summarizes the operating frequency ranges of the inverter compressor during normal operation.
ΠThe OS in the multiple-outdoor-unit system operates at the actual compressor frequency value that is calculated by the OS
based on the preliminary compressor frequency value that the OC determines.
The maximum frequency during heating operation is affected by the outdoor air temperature to a certain extent.
(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.
ΠThe 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.
Œ Operating temperature is 115°C [239°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
Π30 seconds after either compressor start-up or the completion of defrost operation
Π30 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).
Model
Frequency/cooling (Hz) Frequency/heating (Hz)
Max Min Max Min
250 model 97 15 120 15