V6R VRF 50Hz
46
Midea V
6
R
Series S
er
vice M
anual
8
Other Control
8.1
Overload control
Overload control is used to maintain comfort requirement (i.e. outlet air temperature) and keep proper system pressure.
Figure 3-8.1:
Overload control
Notes:
1.
Indoor unit operation ratio = Indoor unit operates capacity index (in the same mode)/ outdoor unit capacity index
8.2
Pump-down Control
Recover refrigerant to outdoor unit
Recover refrigerant to outdoor unit is used to recover the refrigerant from indoor units and MS box before service work. The
LED display r001 in this control.
Table 3-8.1: Recover refrigerant to outdoor unit
Component
Wiring
diagram label
Startup
control
Normal control
Pump down
ODU
Inverter
compressor A
INV1
Tes = -15°C
Upper limit: 60 Hz
30Hz
Inverter fan 1
FANA
PI control
PI control
Inverter fan 2
FANB
Four way valve
ST1
OFF
OFF
OFF
Electronic
expansion valve
EEVA
Refer to
startup control
in cooling
operation
2880pls
2880pls
EEVC
0pls
0pls
Solenoid valve
SV5
ON
ON
SV8A
ON
ON
SV7
OFF
OFF
MS01
Electric ball
valve
EVBA
Cooling only normal control
EVBB
EVBC
Electronic
expansion valve
EEVA
MS04-12
Solenoid valve
SV(n)A
SV(n)B
SVP
Electronic
expansion valve
EEVA
IDU
Fan
Fan
Electronic
expansion valve
EEV
Ending conditions
30min or Pe< 0.2MPa
Meet any points below:
•
Pump down time elapses 5min.
•
Pe < 0.12MPa
•
T7C1_Max ≥ 105°C
•
Pc ≥ 3.6MPa
Notes:
1.
Pc: Discharge pressure Pe: Suction pressure
2.
Tes : Target evapating temperature T7C1: Compressor discharge temperature
Indoor unit operation ratio
≥
130%
Indoor unit operation ratio <105%
Normal operation
Overload control, indoor units operates in
low fan speed