Midea ATOM MDV-V56WDHN1(AtB)

 AtomBSeriesVRF50/60Hz 
  19
Part3‐Control
5 ProtectionControl
5.1 HighPressureProtectionControl(excludemodel28)
Thiscontrolprotectsthesystemfromabnormallyhighpressureand protects the compressors from transient spikes in
pressure.
Figure3‐5.1:Highpressureprotectioncontrol 
Notes: 
1. P
c
:Dischargepressure 
Whenthedischargepressurerisesabove4.4MPathesystemdisplaysP1protectionandtheunitstopsrunning.Whenthe
dischargepressuredropsbelow3.2MPa,thecompressorentersre-startcontrol. 
5.2 LowPressureProtectionControl
Thiscontrolprotectsthesystemfromabnormallylowpressureand protects the compressors from transient drops in
pressure.
Figure3‐5.2:Lowpressureprotectioncontrol 
Notes: 
1.
P
e
:Suctionpressure 
Whensuctionpipepressuredropsbelow0.05MPathesystemdisplaysP2protectionandtheunitstopsrunning.Whenthe
suctionpipepressurerisesabove0.14MPa,thecompressorentersre-startcontrol.
5.3 DischargeTemperatureProtectionControl
This control protects the compressors from abnormally high temperatures and transient spikes in temperature. It is
performedforeachcompressor.
Figure3‐5.3:Highdischargetemperatureprotectioncontrol 


Whenthedischargetemperaturerisesaboveorequalto115°CthesystemdisplaysP4protectionandtheunitstopsrunning.
Whenthedischargetemperaturedropsbelow90°C,thecompressorentersre-startcontrol.
P
c
>4.4MPa P
c
<3.2MPa
Normaloperation
Highpressureprotection,errorcodeP1isdisplayed
P
e
<0.05MPa
P
e
>0.14MPa
Normaloperation
Lowpressureprotection,errorcodeP2isdisplayed
Dischargetemperature≥115°C 
Dischargetemperature<90°C 
Normaloperation
Highdischargetemperatureprotection,errorcodeP4isdisplayed