Midea MGB-D30W/RN1

MCAC-ATSM-2011-12 Air-cooled modular chiller unit 50Hz
151
high-pressure protection of the system B and discharge temperature switch protection (protection code P2);
low-pressure protection of the system A (protection code P1);
low-pressure protection of the system B (protection code P3);
Constant speed compressor: connection of discharge temperature switch and high-pressure switch of the system in series.
13 Inlet water temperature sensor (fault code EF)
14 Shell and tube low-temperature ant-freeze sensor (fault code Eb)
15
Water flow detection (fault code of the main unit E0) is only valid for the main unit but invalid for subordinate units.
1) Main unit: if abnormal water flow occurs for the first and second time, the main unit board will display fault code E9. If
abnormal water flow occurs the third time, the main unit board will display fault code E0 (off-power recovery is needed), and
the wired controller will display fault code E0 (fault is displayed only after 3 detection).
2) Subordinate unit: (water flow detection will not be done).
16 Power phase detection(fault code E8)
17 Electronic expansion valve of the system B
18
Electronic expansion valve of the system A
Electronic expansion valve is used to control refrigerant flow under different operating modes and different loads.
19
Auxiliary electric heater
Attention: the control port value of auxiliary electric heater actually detected is ON/OFF but not 220-230V control power
supply, so special attention should be paid when installing the auxiliary electric heater.
Attention!
Under heating mode, when the main unit board detects total water outlet temperature to be lower than 45℃, the switch will be
closed, and the auxiliary electric heater will begin to work; when the total water outlet temperature is higher than 50℃, the
switch will be opened, and the auxiliary electric heater will stop working.
20
PUMP.
Attention: the control port value of the pump actually detected is ON/OFF but not 220-230V control power supply, so special
attention should be paid when installing the pump.
1) After receiving start-up instruction, the pump will be started up instantly, and will maintain start-up state always in the
process of operation.
2) In case of refrigerating or heating shutdown, the pump will be shut down 2 minutes after all modules stop operating.
3) In case of shutdown under the pump mode, the pump can be directly shut down.
21
One compressor of the system B(B1);
Neutral wire;
Four-way valve of the system B;
Neutral wire.
22
Numerical code tube.
1) In case of stand-by, the address of the module is displayed;
2) In case of normal operation, 10. is displayed (10 is followed by dot).
3) In case of fault or protection, fault code or protection code is displayed.
23
One compressor of the system A(A1);
Neutral wire;
Four-way valve of the system A;
Neutral wire.
24 Outdoor fan A, controlled by T4.
25 Outdoor fan A, controlled by T4.
26 PWM pressure relif valve control(for digital compressor)
27 Input of transformer, 220-230V AC current. (only valid for the main unit)
28
Input of three-phase four-wire power supply (fault code E1)
Three phases A, B and C of power supply should exist simultaneously, and the difference of phase angle should be 120º
among them. If the conditions are not met, fault of phase sequence or phase lack may occur, and fault code will be displayed.