Main Logic; Control Function Of Outdoor Unit - Gree DC Inverter Multi VRF Service Manual

DC INVERTER MULTI VRF

2 MAIN LOGIC

2.1 Control Function of Outdoor Unit

1) Compressor Capacity Output
It is defined that the full load capacity output of the compressor is 100%.
The compressor capacity output is calculated according to the required indoor load, which is
related to the following factors: whether the indoor unit is started, the set temperature, the indoor
ambient temperature, the outdoor ambient temperature, etc.
Calculation of capacity output of cooling compressor
j
∑
= =
1
i
Q
Calculation of capacity output of heating compressor
j
∑
(
= =
1
i
Q
For inverter compressor
× Q
f = F ,and when
max
Among which:
Q is the calculated compressor capacity output;
f Actual run frequency of inverter compressor;
F Maximum allowable run frequency of inverter compressor;
max
F Minimum allowable run frequency of inverter compressor
min
q Rated capacity of indoor unit
i
q Rated capacity of indoor unit in ON state
iON
q Rated capacity of indoor unit in OFF state
iOFF
A Setting temperature, correction of indoor and outdoor ambient temperature,
i
B Capacity compensation under heating when indoor unit in OFF state,
i
2) Compressor Start Control
The shortest operating time of the compressor is 6 minutes. But when the switching-off signal or
the protection signal is received, the compressor must stop even if the operation of it has not
lasted for 6 minutes.
The shortest stoppage period of the compressor is 3 minutes. The compressor must not be
started at any time within 3 minutes after the compressor is stopped.
If the capacity demand of each indoor unit is 0 when the whole unit group is under heating state,
the compressor must be stopped (if under the heating operation alone the temperature of stop
control is reached, the compressor must be stopped).
Initial Sequence Chart of Cooling/Dry Modes:
During the first starting and frequency-rising process of compressor, the first dwell time is
respective 3min, 5min and 5min when the frequency passed 60Hz, 75Hz and 90Hz. If
high-pressure frequency-reducing and exhausting frequency-reducing happens during the
process, you should quit the initial action, and deal with according to their separate
( )
q A
iON i
×
100 %
j
∑
q
i
=
1
i
+ ×
)
q A q B
iON i iOFF i
j
∑
q
i
=
1
i
f is not 0, the minimum is
×
100 %
F the maximum is
min
CONTROL
F
max
44