Midea M-Thermal Series Service Manual page 22

M‐Thermal Split
When the suction pressure drops below 0.14MPa the system displays P0 protection and the unit stops running. When the
suction pressure rises above 0.3MPa, the compressor enters re‐start control.
5.3 Discharge Temperature Protection Control
This control protects the compressor from abnormally high temperatures and transient spikes in temperature.
Figure 3‐5.3: High discharge temperature protection control
Normal operation
Discharge temperature > 115°C
Discharge temperature < 95°C
High discharge temperature protection, error code P4 is displayed
When the discharge temperature rises above 115°C the system displays P4 protection and the unit stops running. When
the discharge temperature drops below 95°C, the compressor enters re‐start control.
Figure 3‐5.4: Low discharge temperature protection control
Normal operation
Tp ≤ Th for more than 5 minutes
Tp ≥ Th
Low discharge temperature protection, error code EA is displayed
When the discharge temperature(Tp) is below sunction temperature(Th) for more than 5 minutes after compressor
operates for 15 minutes, the system displays EA protection and the unit stops running. When the discharge temperature
rises to 27°C or higher, the compressor enters re‐start control.
5.4 Compressor Current Protection Control
This control protects the compressor from abnormally high currents.
Figure 3‐5.5: Compressor current protection control
Normal operation
Current > Current Current < Current
max max
Compressor current protection, error code P3 is displayed
Table 3‐5.1: Current limitation for compressors
Model name MHA‐V4(6)W/D2N8 MHA‐V8(10)W/D2N8
Compressor model SVB172FNPMC‐L SVB220FLGMC‐L
18A 19A
Current
max
When the compressor current rises above Current the system displays P3 protection and the unit stops running. When
max
the compressor current drops below Current , the compressor enters re‐start control.
max
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