mundoclima Aerotherm V17, SO30161, SO30162, SO30163, SO30164 Service Manual

BIBLOC UNIT - AEROTHERM V17

Service Manual

www.mundoclima.com

Thank you very much for purchasing our product.
Before using your unit, please read this manual carefully

and keep it for future reference.

2nd Version

SO30160 to SO30172

English

CONTENTS

MUNDOCLIMA AEROTHERM V17 - BIBLOC

CONTENTS

Part 1 General Information ............................................................................ 3

Part 2 Component Layout and Refrigerant Circuits ..................................... 5

Part 3 Control ............................................................................................... 13

Part 4 Diagnosis and Troubleshooting ......................................................... 27

201703 1

MUNDOCLIMA AEROTHERM V17 - BIBLOC

2 201703

General Information

1 Unit Capacities ........................................................................................... 4

2 External Appearance .................................................................................. 5

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Part 1

Part 1 - General Information

201703 3

1 Unit Capacities

Table 1-1.1: Capacity range

C

apacity

4kW

6kW

8kW

10kW

12kW

14kW

16kW

Capacity

12kW

14kW

16kW

Table 1-2.1: Capacity range

Capacity

8kW

16kW

16kW

Model

Compatible OU model

1.1 Outdoor Unit Capacities

MUNDOCLIMA AEROTHERM V17 - BIBLOC

BIBLOC

V17 (1Ph)

BIBLOC

V17 (3Ph)

SO30160

SO30167

1.2 Hydronic Box Capacities

SO30160 to SO30161

SO30161

SO30168

SO30170

SO30162

SO30169

SO30163 to SO30166

SO30163

SO30171

SO30164

SO30165

SO30166

SO30172

SO30167 to SO30169

4 201703

2 External Appearance

Table 1-2.1: Outdoor unit appearance

4/6kW

8kW

10/12/14/16kW

2.1 Outdoor Unit Appearance

MUNDOCLIMA AEROTHERM V17 - BIBLOC

2.2 Hydronic Box Appearance

Table 1-2.1: Hydronic box appearance

Part 1 - General Information

201703 5

Part 2 - Component Layout and Refrigerant Circuits

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Part 2

Component Layout and

Refrigerant Circuits

1 Layout of Functional Components ......................................................... 6

2 Piping Diagrams .................................................................................... 9

3 Refrigerant Flow Diagrams .................................................................. 12

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1 Layout of Functional Components

Figure 2-1.1:

top view

Figure 2-1.2:

front view

MUNDOCLIMA AEROTHERM V17 - BIBLOC

1.1 Outdoor Unit Layout

Models 4 to 8kW

Air side heat exchanger

Electronic expansion
valve

Liquid

G

ic control box

Electr

side stop valve

as side stop valve

Fan motor

4-

way valve

essure sensor

Pr

essure switch

Low pr

gh pressure switch

Hi

DC inverte

Accumulator

parator

Se

6 201703

r compressor

Part 2 - Component Layout and Refrigerant Circuits

Figure 2-1.4:

top view

Figure 2-1.5:

front view

Models 10 to 16kW

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Air side

heat exchanger

Upper fan motor

Lower fan motor

4-way val

Gas s

Liqui

d side stop valve

tric control box

Elec

ve

ide stop valve

Pressure

igh pressure switch

H

ow pressure switch

L

sensor

Electronic expansion valve

Separator

DC inverter compressorAccumulator

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1.2 Hydronic Box Layout

Figure 2-1.6:

oblique view

tric control box

Elec

Water si

de heat exchanger

MUNDOCLIMA AEROTHERM V17 - BIBLOC

r purge valve

Ai

ectric heater

Backup el

on vessel

Expansi

valve

Safety

ow switch

Water fl

mp

Water pu

nometer

Ma

8 201703

Part 2 - Component Layout and Refrigerant Circuits

2 Piping Diagrams

Figure 2-2.1:

piping diagram

Legend

1

Compressor

7

Electronic expansion valve

2.1

Discharge pipe temperature sensor

8

Accumulator

2.2

Outdoor ambient temperature sensor

9

Stop valve (liquid side)

2.3

Air side heat exchanger refrigerant outlet temperature sensor

10

Stop valve (gas side)

2.4

Suction pipe temperature sensor

11

Pressure sensor

3 4

-way valve

12

Separator

4

Air side heat exchanger

13.1

Low pressure switch

5

Distributor

13.2

High pressure switch

6

Filter

2.1 Outdoor Unit Piping

Models 4 to 8kW

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Key components:

1. Accumulator:
Stores liquid refrigerant and oil to protect compressor from liquid hammering.

2. Electronic expansion valve (EXV):
Controls refrigerant flow and reduces refrigerant pressure.

3. 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.

4. High and low pressure switches:
Regulate refrigerant system pressure. When refrigerant system pressure rises above the upper limit or falls below the
lower limit, the high or low pressure switches turn off, stopping the compressor.

5. Separator:
Separates liquid refrigerant from gas refrigerant to protect compressor from liquid hammering.

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Figure 2-2.2:

piping diagram

Legend

1

Compressor

8

Accumulator

2.1

Discharge pipe temperature sensor

9

Stop valve (liquid side)

2.2

Outdoor ambient temperature sensor

10

Stop valve (gas side)

2.3

Air side heat exchanger refrigerant outlet temperature

sensor

11

Pressure sensor

2.4

Suction

pipe temperature sensor

12

Separator

3

4-way valve

13.1

Low pressure switch

4

Air side heat exchanger

13.2

High pressure switch

5

Distributor

14

Solenoid valve

6

Filter

15

Capillary

7

Electronic expansion valve

Models 10 to 16kW

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Key components:

6. Accumulator:

7. Electronic expansion valve (EXV):

8. Four-way valve:

9. High and low pressure switches:

10. Separator:

11. Solenoid valve:

Stores liquid refrigerant and oil to protect compressor from liquid hammering.

Controls refrigerant flow and reduces refrigerant pressure.

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.

Regulate refrigerant system pressure. When refrigerant system pressure rises above the upper limit or falls below the
lower limit, the high or low pressure switches turn off, stopping the compressor.

Separates liquid refrigerant from gas refrigerant to protect compressor from liquid hammering.

Protects the compressor. If compressor discharge temperature rises above 100°C, 6. Solenoid valve opens and sprays a
small amount of liquid refrigerant to cool the compressor. Solenoid valve closes again once the discharge temperature
has fallen below 90°C.

10 201703

Part 2 - Component Layout and Refrigerant Circuits

2.2 Hydronic box Piping

Figure 2-2.1:

piping diagram

Legend

1

Air purge valve

2

Backup electric heater

Expansion vessel

Refrigerant liquid

13.2

Water side heat exchanger refrigerant inlet (liquid pipe) temperature
sensor

5

Refrigerant gas side

13.3

Water side heat exchanger water outlet temperature sensor

6

Water side heat exchanger

13.4

Water side heat exchanger water inlet temperature sensor

7

Water flow switch

13.5

Backup electric heater water outlet temperature sensor

8

Water pump

14.1

Anti-frozen electric heater for water side heat exchanger

9

Manometer

14.2

Anti-frozen electric heater for water inlet pipe

10

Safety valve

MUNDOCLIMA AEROTHERM V17 - BIBLOC

11 Water outlet
12 Water inlet

3

4

13.1

side

Water side heat exchanger refrigerant outlet (gas pipe) temperature
sensor

Key components:

1. Air purge valve:
Automatically removes air from the water circuit.

2. Safety valve:
Prevents excessive water pressure by opening at 43.5 psi (3 bar) and discharging water from the water circuit.

3. Expansion vessel:
Balances water system pressure. (Expansion vessel volume: 3L.)

4. Water flow switch:
Detects water flow rate to protect compressor and water pump in the event of insufficient water flow.

5. Backup electric heater:
Provides additional heating capacity when the heating capacity of the heat pump is insufficient due to very low
outdoor temperature. Also protects the external water piping from freezing.

6. Manometer:
Provides water circuit pressure readout.

7. Water pump:
Circulates water in the water circuit.

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3 Refrigerant Flow Diagrams

Figure 2-3.1: Refrigerant flow during heating or domestic hot water operation

Figure 2-3.2: Refrigerant flow during cooling and defrosting operations

Heating and domestic hot water operation

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Cooling and defrosting operation

12 201703

Part 3 - Control

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Part 3

Control

1 Stop Operation ........................................................................................ 14

2 Standby Control ....................................................................................... 14

3 Startup Control ........................................................................................ 15

4 Normal Operation Control ....................................................................... 17

5 Protection Control ................................................................................... 19

6 Special Control ......................................................................................... 22

7 Role of Temperature Sensors in Control Functions ................................... 24

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MUNDOCLIMA AEROTHERM V17 - BIBLOC

1 Stop 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 PCB digital displays and on the user
interface.

2. The system stops when the set temperature has been reached.

2 Standby Control

2.1 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 outdoor ambient temperature and the compressor on/off state. When the
outdoor ambient temperature is above 8°C or the compressor is running, the crankcase heater is off; when the outdoor
ambient temperature is at or below 8°C and either the compressor has been stopped for more than 3 hours or the unit has
just been powered-on (either manually or when the power has returned following a power outage), the crankcase heater
turns on.

2.2 Water Pump Control

When the outdoor unit is in standby, the internal and external circulator pumps run continuously.

14 201703

Part 3 - Control

Figure 3-4.1: Compressor startup program

1,2

when ambient temperature is above 4°C

Notes:

stages in a

Figure 3-4.2:

compressor startup program1 when ambient temperature is at or below 4°C

Notes:

stages in a

step-by-step fashion and exits when the target rotation speed has been reached.

MUNDOCLIMA AEROTHERM V17 - BIBLOC

3 Startup Control

3.1 Compressor Startup Delay Control

In initial startup control and in restart control (except in oil return operation and defrosting operation), compressor startup
is delayed such that a minimum of the set re-start delay time has elapsed since the compressor stopped, in order to
prevent frequent compressor on/off and to equalize the pressure within the refrigerant system. The compressor re-start
delays for cooling and heating modes are set on the user interface. Refer to the M-Thermal Split Engineering Data Book
Part 3, 8.5 “COOL MODE SETTING Menu” and Part 3, 8.6 “HEAT MODE SETTING Menu”.

3.2 Compressor Startup Program

In initial startup control and in re-start control, compressor startup is controlled according to outdoor ambient
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 and 3-4.3.

Compressor rotation
speed (rps)

Targ

82rps

40s

et rotation speed

Target rotation

Time (s

speed

Time (

)

s)

86rps

66rps

32rps

60s

36rps

90s

42rps

40s

42rps

60s

40s

56rps

40s

38rps

40s



1. Once the first, 40-second stage of the program is complete, the program proceeds to the subsequent

step-by-step fashion and exits when the target rotation speed has been reached.

2. This program is used on all M-Thermal Split models: 4kW to 16kW, single phase and three phase.

Models 4 to 8kW

Compressor rotation
speed (rps)

38rps

32rps

40s

90s

0

56rps

40s

40s

66rps

40s

1. Once the first, 40-second stage of the program is complete, the program proceeds to the subsequent

201703 15

Figure 3-4.3:

compressor startup program1 when

ambient

Notes:

second stage of the program is complete, the program proceeds to the

stages in a

step-by-step fashion and exits when the target rotation speed has been reached.

I

C

to

ambient

temperature1

DC fan motor / Upper DC fan motor

Fan
Lower DC fan motor

E

Position (steps) from 0 (fully closed) to 480 (fully
open),

outdoor ambient
temperature, discharge temperature and suction
superheat

Four-way valve

ST

On

Notes:

2. Refer to

Table 3

-5.3 in Part 3, 5.6 “Outdoor Fan Control”.

Wiring diagram

l

abel

I

Compressor startup program selected

to

ambient

temperature1

DC fan motor / Upper DC fan motor

FAN1 / FAN_UP

Fan
Lower DC fan motor

FAN_DOWN

E

Position (steps) from 0 (fully

closed) to 480 (fully

open), controlled according to

outdoor ambient
temperature, discharge temperature and

suction

superheat

Four-way valve

ST

Off

Notes:

2. Refer to Table 3-5.3 in Part 3, 5.6 “Outdoor Fan Control”.

Models 10 to 16kW

temperature is at or below 4°C

Compressor rotation
speed (rps)

MUNDOCLIMA AEROTHERM V17 - BIBLOC

66rps

60s

56rps

40s

40s

38rps

40s



1. Once the first, 40-

24rps

90s

33rps

90s

42rps

3.3 Startup Control for Heating and Domestic Hot Water Operation

Table 3-4.1: Component control during startup in heating and domestic hot water modes

Component

nverter compressor COMP ƽ ƽ

lectronic expansion valve EXV ƽ ƽ

Wiring diagram

label

4-8kW 10-16kW

FAN1 / FAN_UP ƽ ƽ

FAN_DOWN ƽ

Target rotation sp

82rps

40s

eed

Time (s)

subsequent

Control functions and states

ompressor startup program selected according

run at maximum speed2

controlled according to

ƽ ƽ

1. Refer to Figure 3-4.1, Figure 3-4.2 and Figure 3-4.3 in Part 3, 4.2 “Compressor Startup Program”.

3.4 Startup Control for Cooling Operation

Table 3-4.2: Component control during startup in cooling mode

Component

nverter compressor COMP ƽ ƽ

lectronic expansion valve EXV ƽ ƽ

1. Refer to Figure 3-4.1, Figure 3-4.2 and Figure 3-4.3 in Part 3, 4.2 “Compressor Startup Program”.

4-8kW

ƽ ƽ

ƽ

ƽ ƽ

10-16kW

Control functions and states

according

run at maximum speed2

16 201703

Part 3 - Control

Wiring diagram

I

Controlled

from

hydronic system

DC fan motor / Upper DC fan motor

FAN1 / FAN_UP

Controlled

outdoor heat exchanger

pipe temperature

Lower DC fan motor

FAN_DOWN

E

Position (steps) from 0 (fully closed) to 480 (fully
open)

discharge

temperature

, suction superheat and compressor

speed

F

O

I

ƽ

Controlled

from

hydronic system

DC fan motor / Upper DC fan motor

FAN1 / FAN_UP

Controlled according to outdoor heat exchanger pipe
temperature

Lower DC fan motor

FAN_DOWN

E

Position (steps) from 0 (fully closed) to 480 (fully
open)

according to discharge

temperature

and compressor

speed

F

O

4 Normal Operation Control

4.1 Component Control during Normal Operation

Table 3-5.1: Component control during heating and domestic hot water operations

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Component

nverter compressor

label

COMP

lectronic expansion valve EXV

our-way valve ST

Table 3-5.2: Component control during cooling operation

Component

nverter compressor

Wiring diagram

label

COMP

4-8kW

ƽ ƽ

ƽ ƽ

ƽ ƽ

ƽ ƽ

10-16kW

ƽ

4-8kW 10-16kW

ƽ

ƽ ƽ

ƽ

Control functions and states

according to load requirement

according to

, controlled according to

n

Control functions and states

according to load requirement

lectronic expansion valve EXV

ƽ ƽ

, controlled

, suction superheat

our-way valve ST

ƽ ƽ

ff

4.2 Compressor Output Control

The compressor rotation speed is controlled according to the load requirement. Before compressor startup, the
M-Thermal Split outdoor unit determines the compressor target speed according to outdoor ambient temperature, leaving
water set temperature and actual leaving water temperature and then runs the appropriate compressor startup program.
Refer to Part 3, 4.2 “Compressor Startup Program”. Once the startup program is complete, the compressor runs at the
target rotation speed.

During operation the compressor speed is controlled according to the rate of change in water temperature, the refrigerant
system pressure and the refrigerant temperature.

4.3 Compressor Step Control

The running speed of four-pole compressors (used on 5-7kW models) in rotations per second (rps) is half the frequency (in
Hz) of the electrical input to the compressor motor. The running speed of six-pole compressors (used on all other models)
in rotations per second (rps) is one third of the frequency (in Hz) of the electrical input to the compressor motor. The
frequency of the electrical input to the compressor motors can be altered at a rate of 1Hz per second.

201703 17

Table 3-5.3: Outdoor fan speed steps

Fan speed index

Upper fan1

Lower fan2

Upper fan1

Lower fan2

600

Notes:

Engineering Data Book

Engineering Data Book

Part 2, 4 “Wiring diagram”.

MUNDOCLIMA AEROTHERM V17 - BIBLOC

4.4 Four way Valve Control

The four-way valve is used to change the direction of refrigerant flow through the water side heat exchanger in order to
switch between cooling and heating/DHW operations. Refer to Figures 2-3.1 and 2-3.2 in Part 2, 3 “Refrigerant Flow
Diagrams”.

During heating and DHW operations, the four-way valve is on; during cooling and defrosting operations, the four-way
valve is off.

4.5 Electronic Expansion Valve Control

The position of the electronic expansion valve (EXV) is controlled in steps from 0 (fully closed) to 480 (fully open).

 At power-on:

y The EXV first closes fully, then moves to the standby position (304 (steps)). After 30 seconds the EXV moves to an

initial running position, which is determined according to operating mode and outdoor ambient temperature.
After a further 150 seconds, the EXV is controlled according to suction superheat and discharge temperature.
Once a further 6 minutes have elapsed, the EXV is then controlled according to suction superheat, discharge
temperature and compressor speed.

 When the outdoor unit is in standby:

y The EXV is at position 304 (steps).

 When the outdoor unit stops:

y The EXV first closes fully, then moves to the standby position (304 (steps)).

4.6 Outdoor Fan Control

The speed of the outdoor unit fan(s) is adjusted in steps, as shown in Table 3-5.3.

Fan speed (rpm)

4kW

6kW

8kW

10-16kW (1Ph) 12-16kW (3Ph)

0 0 0 0 0 0 0 0

1 300

2 340

3 400

4 450

5 520

6

7 680

8 730

9 800

1. The upper fan is labelled FAN_UP in the wiring diagram. Refer to the M-Thermal Split
Part 2, 4 “Wiring diagram”.

2. The lower fan is labelled FAN_DOWN in the wiring diagram. Refer to the M-Thermal Split

300
340
400
450
520
600
680
730
800

300
340
400
450
520
600
680
730
800

300 - 300 ­330 300 330 300
400 380 400 380
460 440 460 440
520 500 520 500
630 610 630 610
780 760 780 760

- - - -

- - -

-

18 201703

Part 3 - Control

Figure 3-6.1: High pressure protection control

Figure 3-6.2: Low pressure protection control

Notes:

Figure 3

-6.3: High discharge temperature protection control

When P

protection occurs 3 times
in 60 minutes, the HP error is
displayed. When an H

error occurs,
a manual system restart is required
before the system can resume
operation.

MUNDOCLIMA AEROTHERM V17 - BIBLOC

5 Protection Control

5.1 High Pressure Protection Control

This control protects the refrigerant system from abnormally high pressure and protects the compressor from transient
spikes in pressure.

Normal operation

Pc > 4.4MPa Pc < 3.2MPa

High pressure protection, error code P1 is displayed

Notes:

1. P

: Discharge pressure

c

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 refrigerant system from abnormally low pressure and protects the compressor from transient
drops in pressure.

Normal operation

Pe < 0.14MPa

Pe > 0.30MPa

Low pressure protection, error code P0 is displayed

1. Pe: Suction pressure

0

P

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.

Discharge temperature > 115°C

When the discharge temperature rises above 115°C the system displays P4 protection and the unit stops running. When

201703 19

Normal operation

Discharge temperature < 90°C

High discharge temperature protection, error code P4 is displayed

Figure 3

-6.4:Low discharge temperature protection control

Figure 3

-6.5: Compressor current protection control

Table 3

Compressor model

ATF250D22UMT

ATQ420D2UMU

Figure 3-6.4: Compressor voltage protection control

MUNDOCLIMA AEROTHERM V17 - BIBLOC

the discharge temperature drops below 90°C, the compressor enters re-start control.

Normal operation

Discharge temperature ≤ 15°C for

Discharge temperature ≥27°C

more than 5 minutes

Low discharge temperature protection, error code EA is displayed

When the discharge temperature is at or below 15°C for more than 5 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.

Normal operation

Current > Current

Compressor current protection, error code P3 is displayed

Current < Current

max

max

-6.1: Current limitation for compressors

Model name

Current

max

When the compressor current rises above Current
the compressor current drops below Current

Models 4 and 6kW

SNB172FJFMC

18A 20A 31A 15A

Model 8kW

the system displays P3 protection and the unit stops running. When

max

, the compressor enters re-start control.

max

Models 10 to 16kW (1Ph) Models 10 to 16kW (3Ph)

ATQ420D1UMU

5.5 Voltage Protection Control

This control protects the M-Thermal Split from abnormally high or abnormally low voltages.

Normal operation

Voltage ≥ 265V

or Voltage ≤ 172V

Compressor voltage protection, error code H7 is displayed

256V < Voltage < 180V

When the phase voltage of AC power supply is at or above 265V for more than 30 seconds, the system displays H7
protection and the unit stops running. When the phase voltage drops below 265V for more than 30 seconds, the

20 201703

Part 3 - Control

refrigerant system restarts once the compressor re-start delay has elapsed. When the phase voltage is below 172V, the
system displays H7 protection and the unit stops running. When the AC voltage rises to more than 180V, the refrigerant
system restarts once the compressor re-start delay has elapsed.

MUNDOCLIMA AEROTHERM V17 - BIBLOC

5.6 DC Fan Motor Protection Control

This control protects the DC fan motors from strong winds and abnormal power supply. DC fan motor protection occurs
when any one of the following the following three sets of conditions are met:

 Outdoor ambient temperature is at or above 4°C and actual fan speed differs from target fan speed by 200rpm or

more for more than 3 minutes.

 Outdoor ambient temperature is below 4°C and actual fan speed differs from target fan speed by 300rpm or more for

more than 3 minutes.

 Actual fan speed is less than 240rpm for more than 20 seconds.

When DC fan motor protection control occurs the system displays the H6 error code and the unit stops running. After 3
minutes, the unit restarts automatically. When H6 protection occurs 10 times in 120 minutes, the HH error is displayed.
When an HH error occurs, a manual system restart is required before the system can resume operation.

5.7 Water Side Heat Exchanger Anti-freeze Protection Control

This control protects the water side heat exchanger from ice formation. The water side heat exchanger electric heater is
controlled according to outdoor ambient temperature, water side heat exchanger water inlet temperature and water side
heat exchanger water outlet temperature.

In heating mode, if the outdoor temperature falls below 3°C and either the water side heat exchanger water inlet
temperature or water side heat exchanger water outlet temperature are below 25°C, the water side heat exchanger
electric heater turns on. When the outdoor ambient temperature rises above 5°C and either the water side heat exchanger
water inlet temperature or water side heat exchanger water outlet temperature are above 30°C, the water side heat
exchanger turns off.

When water side heat exchanger anti-freeze protection occurs the system displays error code Pb and the unit stops
running.

201703 21

Table 3-7.1: Outdoor unit component control during oil return operation in cooling mode

Inverter compressor

Runs

at oil return operation rotation speed

DC fan motor / Upper DC fan motor

Controlled according to outdoor heat exchanger pipe
temperature

Lower DC fan motor

E

304 (steps)

Four-way valve

ST

Off

Table 3-7.2: Outdoor unit component control during oil return operation in heating and DHW modes

Wiring diagram

label

Inverter compressor

COMP

Runs

at oil return operation rotation speed

DC fan motor / Upper DC fan motor

FAN1 / FAN_UP

Controlled according to outdoor heat exchanger pipe
temperature

Lower DC fan motor

FAN_DOWN

E

ƽ

304 (steps)

Four-way valve

ST

On

MUNDOCLIMA AEROTHERM V17 - BIBLOC

6 Special Control

6.1 Oil Return Operation

In order to prevent the compressor from running out of oil, the oil return operation is conducted to recover oil that has
flowed out of the compressor and into the refrigerant piping. When the oil return operation is being conducted, the
outdoor unit refrigerant system main PCB displays code d0.

Timing of oil return operation:

 When the compressor cumulative operating time with running rotation speed less than 42rps reaches 6 hours.

The oil return operation ceases when any one of the following three conditions occurs:

 Oil return operation duration reaches 5 minutes.
 Compressor stops.
 Mode change command is received.

Tables 3-7.1 show component control during oil return operation in cooling mode.

Component

lectronic expansion valve EXV ƽ ƽ

Wiring diagram

label

COMP ƽ ƽ

FAN1 / FAN_UP ƽ ƽ

FAN_DOWN ƽ

4-8kW 10-16kW

ƽ ƽ

Control functions and states

Tables 3-7.2 show component control during oil return operation in heating and DHW modes.

Component

lectronic expansion valve EXV

4-8kW

ƽ ƽ

ƽ ƽ

ƽ

ƽ

ƽ ƽ

10-16kW

Control functions and states

6.2 Defrosting Operation

In order to recover heating capacity, the defrosting operation is conducted when the outdoor unit air side heat exchanger
is performing as a condenser. The defrosting operation is controlled according to outdoor ambient temperature, air side
heat exchanger refrigerant outlet temperature and the compressor running time.

The defrosting operation ceases when any one of the following three conditions occurs:

 Defrosting operation duration reaches 10 minutes.
 The air side heat exchanger refrigerant outlet temperature is above 8°C for more than 10 seconds.
 The air side heat exchanger refrigerant outlet temperature is above 10°C.

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Part 3 - Control

Table 3-7.3: Component control during defrosting operation

Wiring diagram

label

Inverter compressor

COMP

Runs

at defrosting operation rotation

speed

DC fan motor / Upper DC fan motor

FAN1 / FAN_UP

Off
Lower DC fan motor

FAN_DOWN

E

F

Four-way valve

ST

Off

I

Runs at

rotation

DC fan motor / Upper DC fan motor

Runs at force cooling operation

Lower DC fan motor

E

lectronic expansion valve

304 (steps)

F

O

Wiring diagram

I

nverter compressor

COMP

Controlled

DC fan motor / Upper DC fan motor

FAN1 / FAN_UP

Controlled according to outdoor heat exchanger pipe
temperature

Lower DC fan motor

FAN_DOWN

E

Position (steps) from 0 (fully closed) to 480 (fully
open), controlled

F

O

Tank electric heater

On

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Component

lectronic expansion valve EXV ƽ ƽ

4-8kW

ƽ ƽ

ƽ ƽ

ƽ

ƽ ƽ

10-16kW

Control functions and states

ully open

6.3 Force Cooling Operation

The force cooling operation helps the refrigerant recovering before removal the water side heat exchanger.

The force cool mode can be ended by pushing the button on the outdoor refrigerant system main PCB named “force-cool”
for 5s or this mode will be ended automatic if the system has operated force cool mode for more than 30 minutes.

Table 3-7.4: Component control during force cool operation

Component

nverter compressor

Wiring diagram

label

COMP

FAN1 / FAN_UP

FAN_DOWN

4-8kW 10-16kW

ƽ ƽ

ƽ ƽ

ƽ

Control functions and states

force cooling operation

speed

speed

EXV

our-way valve ST

ƽ ƽ

ƽ ƽ

ff

6.4 Fast DHW Operation

Fast DHW operation is used to quickly meet a requirement for domestic hot water when DHW priority has been set on the
user interface. Refer to the M-Thermal Split Engineering Data Book Part 3, 8.4 “DHW MODE SETTING Menu”.

Domestic hot water demand priority can be ended by changing the switch on controller from "on" to "off".

Table 3-7.5: Component control during fast DHW operation

Component

lectronic expansion valve EXV

our-way valve ST

TBH

label

4-8kW

ƽ ƽ

ƽ ƽ

ƽ ƽ

ƽ ƽ

ƽ

10-16kW

ƽ

ƽ

n

Control functions and states

according to load requirement

according to discharge superheat

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Figure 3-7.1: Location of the temperature sensors on M-Thermal Split systems

Notes:

1. The names and functions of the temperature sensors labelled 1 to 12 in

this figure are detailed in Table 3

-7.1.

7 Role of Temperature Sensors in Control Functions

MUNDOCLIMA AEROTHERM V17 - BIBLOC

24 201703

Part 3 - Control

Table 3-7.1: Names and functions of the temperature sensors

Number

Sensor

code

Discharge pipe
sensor

 Electronic expansion valve control2
 Discharge

super

heat control

 Electronic expansion valve control2

 Discharge superheat control

Outdoor a

temperature

sensor

 Compressor startup control4

xpansion valve control

 Crankcase heater control9

 Compressor startup control4



Crankcase heater

control9

Air side
refrigerant

temperature

sensor

Electronic expansion valve control2

Outdoor fan control3

Water side heat exchanger

refrigerant inlet

temperature sensor

5

Water side heat exchanger

refrigerant outlet (gas pipe)

temperature sensor

Suction pipe

temperature

sensor

Heating

Cooling

Water side heat exchanger

water i

sensor

Tw

Water side heat exchanger

water out

sensor

Tw

_out

Heating

Cooling

DHW

Backup electric heater
o

 Compressor output control5

 Auto mode control

 Compressor output5 and on/off control6
 Auto mode control

 Compressor output control5

 DHW priority control11

Auxiliary heat source

water

outlet temperature sensor

 Auxiliary heat source control
 Compressor output control

Room

 Auto mode control

 Compressor output control5

Domestic hot water
temperature

 Disinfection operation control

 DHW priority control11

Notes:

to refrigerant flow is

refer to

5. Refer to Part 3, 4.2 “Compressor Output Control”.

10.

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Sensor name1

Mode Control functions

Heating

1

2

temperature

mbient

Tp

T4

Cooling

Heating

Cooling

 Outdoor fan control3

 Compressor output control5
 Electronic e
 Defrosting operation control

7

 Low pressure protection control

 Compressor output control5
 Electronic expansion valve control
 Outdoor fan control

3

2

7

2



heat exchanger

3

outlet

T3

Heating

Cooling

 Defrosting operation control7


 Compressor output control
 Outdoor fan control

5

3

Heating

4

(liquid pipe)

T2B

 Compressor output control5

DHW

6

7

8

9

10

11

12

nlet temperature

utlet temperature sensor

temperature sensor Ta

let temperature

water

tank

sensor

T2 Heating  Freeze prevention control10

Th

 Electronic expansion valve control2

Heating

_in

 Freeze prevention control

Cooling

 Compressor output5 and on/off control6
 Freeze prevention control

 Backup electric heater control
 DHW priority control11

 Backup electric heater control

T1

Heating

Cooling

DHW

T1B Heating

Heating
Cooling

 Climate related curve

 DHW tank immersion heater control
 Backup electric heater control

T5 DHW

 Auxiliary heat source control
 Solar energy kit control
 Compressor output control5

10

10

5

1. Sensor names in this service manual referring
named according refrigerant flow during cooling operation
Part 2, 3 “Refrigerant Flow Diagrams”.

2. Refer to Part 3, 4.5 “Electronic Expansion Valve Control”.

3. Refer to Part 3, 4.6 “Outdoor Fan Control”.

4. Refer to Part 3, 3 “Startup Control”.

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6. Refer to Part 3, 1 “Stop Operation”.

7. Refer to Part 3, 6.2 “Defrosting Operation”.

8. Refer to Part 3, 5.2 “Low Pressure Protection Control”.

9. Refer to Part 3, 2.1 “Crankcase Heater Control”.
Refer to Part 3, 2.2 “Freeze Prevention Control”.

11. Refer to Part 3, 6.4 “Fast DHW Operation”.

MUNDOCLIMA AEROTHERM V17 - BIBLOC

26 201703

Part 4 - Diagnosis and Troubleshooting

MUNDOCLIMA AEROTHERM V17 - BIBLOC

Part 4

Diagnosis and

Troubleshooting

1 Electric Control Box Layout ....................................................................... 28

2 PCBs ......................................................................................................... 31

3 Error Code Table ....................................................................................... 45

4 Troubleshooting ....................................................................................... 47

5 Appendix to Part 4 ................................................................................... 98

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1 Electric Control Box Layout

Figure 4-1.1:

electric control box

P

Communication terminal blocks

M

Inverter module

C

Transfor

Figure

Figure 4-1.3:

side view

Transformer

M

module

ors

Communication
terminal blocks

ridge rectifier

Power supply
terminals

1.1 Outdoor Unit Electric Control Box Layout

Models 4 to 8kW

MUNDOCLIMA AEROTHERM V17 - BIBLOC

ower supply terminals

ain PCB

apacitor

mer

Models 10 to 16kW (1Ph)

4-1.2:

electric control box

ain PCB

Inverter

electric control box

Capacit

B

28 201703