Midea Aqua Tempo Super II Series User manual

Commercial Air Conditioners
Service
Manual

Aqua Tempo Super II
201709 1
CONTENTS
CONTENTS
Part 1 General Information............................................................................ 3
Part 2 Component Layout and Refrigerant Circuits ..................................... 5
Part 3 Control ............................................................................................... 15
Part 4 Diagnosis and Troubleshooting......................................................... 33

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Aqua Tempo Super II
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Part 1 - General Information
Part 1
General Information
1 Unit Capacities and External Appearance ................................................... 4
2 Water outlet temperature range ................................................................ 4

M-Thermal Mono
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Midea Aqua Tempo Super II Service Manual
1Unit Capacities and External Appearance
Table 1-2.1: Aqua Tempo Super II unit capacity range and unit appearances
Capacity
30kW
60kW
Model
MC-SU30-RN1L
MC-SU30-RN1L
Appearance
Power supply
380-415V/3Ph/50Hz
2Water outlet temperature range
Table 1-2.1: Aqua Tempo Super II unit water outlet temperature range
Mode
Range
Cooling
Normal
5-20°C
Low water outlet
0-20°C
Heating
Normal
25-55°C
Note:
1. Use dial switch S5_1 on the main PCB to select the water outlet temperature range.

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Part 2 - Component Layout and
Refrigerant Circuits
Part 2
Component Layout and
Refrigerant Circuits
1Layout of Functional Components ...........................................................6
2Piping Diagrams .....................................................................................10
3Refrigerant Flow Diagrams.....................................................................13

Aqua Tempo Super II
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Midea
Aqua Tempo Super II
Service Manual
1Layout of Functional Components
MC-SU30-RN1L
Figure 2-1.1: MC-SU30-RN1Lfront view
Figure 2-1.2: MC-SU30-RN1L rear view
Fan motor
Electric
control box
Manual air
purge valve
Safety
valve
Manual water
drain valve
Water flow switch
Water side heat exchanger
Water inlet pipe
Water outlet
pipe
DC inverter
compressor
Accumulator Oil separator
Wired
controller

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Part 2 - Component Layout and
Refrigerant Circuits
Figure 2-1.3: MC-SU30-RN1L top view
Low pressure
switch
Solenoid valve
SV4
High pressure
sensor
Four-way valve
High pressure
switch
Electronic
expansion valve
Discharge
temperature
switch
High pressure
gauge point
Low pressure
gauge point
Accumulator

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Aqua Tempo Super II
Service Manual
MC-SU60-RN1L
Figure 2-1.4: MC-SU60-RN1Lfront view
Figure 2-1.5: MC-SU60-RN1L rear view
Fan motor
Electric
control box
DC inverter
compressor
Oil separator
Accumulator
Accumulator
Water side
heat exchanger
Water flow
switch
Air purge valve
Safety valve
Water inlet pipe
Wateroutlet
pipe
Manual water
drain valve

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Part 2 - Component Layout and
Refrigerant Circuits
Figure 2-1.6: MC-SU60-RN1L top view
High pressure
sensor
High pressure
switch
Four-way valve
Electronic
expansion valve
Low pressure
switch
Solenoid
valve SV4
Discharge
temperature
switch
High pressure
gauge point
Low pressure
gauge point

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Service Manual
2Piping Diagrams
MC-SU30-RN1L
Figure 2-2.1: MC-SU30-RN1L piping diagram
TP1
TP2
T3
T4
EXV
SV4
Twi
Two
Taf1
Tz/7
Taf2 Tw
ST1
12
3
4
5
6
7
8
9
10
11
Th
Legend
1Compressor Tp1 Discharge temperature sensor 1
2Low pressure switch Tp2 Discharge temperature sensor 2
3Discharge temperature control switch T3 Air side heat exchanger refrigerant outlet
temperature sensor
4Highpressureswitch T4 Outdoor ambient temperature sensor
5Oil separator TZ/7 Air side heat exchanger refrigerant total outlet
temperature sensor
6Air side heat exchanger Taf1 Water side heat exchanger anti-freezing
temperature sensor 1
7Pressure sensor Taf2 Water side heat exchanger anti-freezing
temperature sensor 2
8Accumulator Twi Water side heat exchanger water inlet temperature
sensor
9Water side heat exchanger Two Water side heat exchanger water outlet
temperature sensor
10 Water flow switch Tw Combined water outlet temperature sensor
11 Filter Th Air suction temperature sensor
EXV Electronic expansion valve SV4 Oil return solenoid valve
ST1 4-way valve

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Part 2 - Component Layout and
Refrigerant Circuits
MC-SU60-RN1L
Figure 2-2.2: MC-SU60-RN1L piping diagram
Legend
1Compressor Tp1 Discharge temperature sensor 1
2Low pressure switch Tp2 Discharge temperature sensor 2
3Discharge temperature control switch T3 Air side heat exchanger refrigerant outlet
temperature sensor
4Highpressureswitch T4 Outdoor ambient temperature sensor
5Oil separator TZ/7 Air side heat exchanger refrigerant total outlet
temperature sensor
6Air side heat exchanger Taf1 Water side heat exchanger anti-freezing
temperature sensor 1
7Pressure sensor Taf2 Water side heat exchanger anti-freezing
temperature sensor 2
8Accumulator Twi Water side heat exchanger water inlet temperature
sensor
9Water side heat exchanger Two Water side heat exchanger water outlet
temperature sensor
10 Water flow switch Tw Combined water outlet temperature sensor
11 Filter Th Air suction temperature sensor
EXV Electronic expansion valve SV4 Oil return solenoid valve
ST1 4-way valve
Tp2
T3
T4
SV4
Tp1
Twi
Tz
Capillary
Taf1
EXV
ST1
Taf2
1.1
3
1.2
4
5
6
7
8
9
Two Tw
10
11
Th

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Key components:
1. Compressor
Maintains pressure differential between high and lowpressure sides of the refrigerant system.
2. Fan
Ventilates the air side heat exchanger.
3. Oil separator:
Separates oil from gas refrigerant pumped out of the compressor and quickly returns it to the compressor. Separation
efficiency is upto 99%.
4. Accumulator:
Stores liquid refrigerant and oil to protect the compressor from liquid hammering.
5. Electronic expansion valve (EXV):
Controls refrigerant flowand reduces refrigerant pressure.
6. Four-way valve:
Controls refrigerant flow direction. Closed in cooling mode and open in heating mode. When closed, the air side heat
exchanger functions as a condenser and water side heat exchanger functions as an evaporator; when open, the air
side heat exchanger functions as an evaporator and water side heat exchanger function as a condenser.
7. High and low pressureswitches:
Regulate refrigerant system pressure. When the refrigerant system pressure rises above the upper limit orfallsbelow
the lower limit, the high or low pressure switches turn off, stopping the compressor.
8. Discharge temperature switch:
Protects the compressor from abnormally high temperatures and transient spikes intemperature.
9. Air purge valve:
Automatically removes air from the water circuit.
10.Safety valve
Prevents excessivewater pressure by opening at 43.5psi (3bar) and discharging water from the water circuit.
11.Water flow switch:
Detects water flow rate to protect thecompressor and water pump in the event of insufficient water flow.
12.Water pump:
Circulates water in thewater circuit.
13.Pressure sensor
Measures refrigerant system pressure.
14.Crankcase heater
Prevents refrigerant from mixing with compressor oil when the compressors are stopped.
15.Water side heat exchanger electric heater
Protects thewater side heat exchanger from ice formation.
16.Water flowswitch electric heater:
Provides additional heating when heating capacity provided by the heat pump is insufficient due to low ambient
temperatures, it also protects external water pipes from freezing.
17.Solenoid valveSV4
Returns oil to the compressor. It opens after 17 minutes of compressor operation, closes after 3 minutes, then opens
again for 3 minutes at 17 minute increments.

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Part 2 - Component Layout and
Refrigerant Circuits
3Refrigerant Flow Diagrams
Heating operation
Figure 2-3.1: Refrigerantflowduring heating operation
Cooling and defrosting operation
Figure 2-3.2: Refrigerantflowduring cooling and defrosting operations

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Service Manual

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Part 3 - Control
Part 3
Control
1 General Control Scheme Flowchart ..................................................... 16
2 Stop Operation.................................................................................... 17
3 Standby Control .................................................................................. 17
4 Startup Control.................................................................................... 18
5 Normal Operation Control................................................................... 20
6 Protection Control............................................................................... 23
7 Special Control .................................................................................... 29
8 Role of Temperature Sensors in Control Functions............................... 31

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1General Control Scheme Flowchart
Sections 3-2 to 3-7 on the following pages detail when each of the controls in the flowchart below is activated.
Note:
1. Numbers in the top right-hand corners of boxes indicate the relevant section of text on the following pages.
S5_4 on main
PCB set to ON
Conditions met
for defrosting
Thermo on
Special control
Outdoor unit duty cycling
Additional control
Defrosting operation
7
Stop operation
Abnormal shutdown
System stops
2
Standby control
Crankcase heater control
Water pump control
3
Startup control
Compressor startup delay control
Compressor startup program
Startup control for heating operation
Startup control for cooling operation
4
Thermo on
Normal operation control
Component control during normal operation
Compressor output control
Compressor step control
Water pump select control
Four-way valve control
Electronic expansion valve control
Outdoor fan control
5
Protection control
High pressure protection control
Low pressure protection control
Discharge temperature protection control
Compressor and inverter module protection control
Voltage protection control
DC fan motor protection control
Water side heat exchanger anti-freeze protection control
Air side heat exchanger high temperature protection control
Water side heat exchanger temperature difference protection control
Water side heat exchanger low temperature protection control
6

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Part 3 - Control
2Stop Operation
The stop operation occurs for one of the following reasons:
1. Abnormal shutdown: in order to protect the compressors, if an abnormal state occurs the system makes a 'stop with
thermo off’operation and an error code is displayed on the outdoor unit’s PCB digital displays and on the user
interface.
2. The system stops when the set temperature has been reached.
3Standby Control
3.1 Crankcase Heater Control
The crankcase heater is used to prevent refrigerant from mixing with compressor oil when the compressors are stopped.
The crankcase heater is controlled according to the outdoor ambient temperature and discharge temperature. When the
outdoor ambient temperature is above 40°C, the crankcase heater is off; when the outdoor ambient temperature is below
35°C, the crankcase heater is controlled according to discharge temperature. Refer to Figures 3-3.1 and 3-3.2.
Figure 3-3.1: Crankcase heater controlled according to outdoor ambient temperature
Figure 3-3.2: Crankcase heater controlled according to discharge temperature
Notes:
1. Tp1: discharge temperature sensor 1, Tp2: discharge temperature sensor 2.
3.2 Water Pump Control
When the outdoor unit is in standby, the circulator pumps run continuously。
Ambient temperature < 35 oC
Ambient temperature > 40 oC
Crankcase heater off
Crankcase heater is controlled according to discharge temperature
Max (Tp1, Tp2) < 40 oC
Max (Tp1, Tp2) > 50 oC
Crankcase heater off
Crankcase heater on

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4Startup Control
4.1 Compressor Startup Delay Control
In initial startup control and restart control (except in defrosting operation), compressor startup is delayed such that a
minimum 7 minutes has elapsed since the compressor stopped, in order to prevent frequency compressor on/off and to
equalize the pressure within the refrigerant system.
4.2 Compressor Startup Program
In initial startup control and in re-start control, compressor startup is controlled according to outdoor ambient
temperature and discharge temperature. Compressor startup follows one of two startup programs until the target rotation
speed is reached. Refer to Figures 3-4.1, 3-4.2.
Figure 3-4.1: Compressor startup program1 when ambient temperature is above 10°C
Notes:
1. Once the first, 60-second stage of the program is complete, the program proceeds to the subsequent stages in a
step-by-step fashion and exits when the target rotation speed has been reached.
Figure 3-4.2: Compressor startup program1when ambient temperature is at or below 10°C
Notes:
1. Once the first, 90-second stage of the program is complete, the program proceeds to the subsequent stages in a
step-by-step fashion and exits when the target rotation speed has been reached.
42rps
60S
56rps
34rps
66rps
76rps
80rps
90rps
90S
90S
90S
90S
180S
60S
180S
100rps
Target rotation speed
Compressor
rotation speed (rps)
Time (s)
105rps
300S
42rps
90S
28rps
120S
34rps
60S
42rps
90S
56rps
60S
76rps
60S
66rps
60S
80rps
90S
90rps
180S
100rps
180S
Target rotation speed
Compressor
rotation speed (rps)
Time (s)
105rps
300S

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Part 3 - Control
4.3 Startup Control for Heating Operation
Table 3-4.1: Component control during startup in heating mode
Component
Wiring diagram
label
30kW
60kW
Control functions and states
Inverter compressor A
COMP A
●
●
Compressor startup program selected according to
ambient temperature and discharge temperature1
Inverter compressor B
COMP B
●
DC fan motor A
FAN A
●
●
Controlled according to ambient temperature
DC fan motor B
FAN B
●
Electronic expansion valve
EXV 1
●
●
Position (steps) from 0 (fully closed) to 480 (fully
open), controlled according to outdoor ambient
temperature, unit capacity.
Four-way valve
STF1
●
●
On after the compressor startup for 10s
Solenoid valve (oil balance)
SV4_1
●
●
Closed for 200s, open for 600s, then closed
Water pump1
PUPM1
●
●
On
Water pump2
PUPM2
●
●
Water side heat exchanger heater 1
EVA-HEAT 1
●
●
According to water side heat exchanger
anti-freezing temperature (Taf)
Water side heat exchanger heater 2
EVA-HEAT 2
●
Water flow switch heater
W-HEAT1
●
●
Controlled according to ambient temperature, water
inlet temperature and water outlet temperature
Electric auxiliary heater
E-HEAT_L/
E-HEAT_N
●
●
Controlled according to ambient temperature and
total water outlet temperature after the compressor
is on
Crank case heater 1
HEAT1
●
●
Controlled according to ambient temperature and
discharge temperature
Crank case heater 2
HEAT2
●
Notes:
1. Refer to Figure 3-4.1, Figure 3-4.2 and in Part 3, 4.2 “Compressor Startup Program”.
4.4 Startup Control for Cooling Operation
Table 3-4.2: Component control during startup in cooling mode
Component
Wiring diagram
label
30kW
60kW
Control functions and states
Inverter compressor A
COMP A
●
●
Compressor startup program selected according to
ambient temperature and discharge temperature1
Inverter compressor B
COMP B
●
DC fan motor A
FAN A
●
Controlled according to air side heat exchanger
refrigerant total outlet temperature (Tz/7)
DC fan motor B
FAN B
●
Electronic expansion valve
EXV 1
●
●
Position (steps) from 0 (fully closed) to 480 (fully
open), controlled according to outdoor ambient
temperature, outdoor unit initial frequency
Four-way valve
STF1
●
●
Off
Solenoid valve (oil balance)
SV4_1
●
●
Closed for 200s, open for 600s, then closed
Water pump1
PUPM1
●
●
On
Water pump2
PUPM2
Water side heat exchanger heater 1
EVA-HEAT 1
●
●
According to water side heat exchanger
anti-freezing temperature (Taf)
Water side heat exchanger heater 2
EVA-HEAT 2
●
Water flow switch heater
W-HEAT1
●
●
Controlled according to ambient temperature, water
inlet temperature and water outlet temperature
Electric auxiliary heat
E-HEAT_L/
E-HEAT_N
●
●
Off
Crank case heater 1
Heat 1
●
●
Controlled according to ambient temperature and
discharge temperature
Crank case heater 2
Heat 2
●
Notes:
1. Refer to Figure 3-4.1, Figure 3-4.2 and in Part 3, 4.2 “Compressor Startup Program”.