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61 

  Once the indoor unit is ON, the water pump will be ON immediately and no error judgement for 9 minutes. 

However, during this 9 minutes operation, if there is any abnormality cause at outdoor or malfunction, the 
compressor should be OFF immediately and restart delay after 3 minutes. 

  The system will start checking on the water flow level after operation start for 9 minutes. If water flow level is 

detected low continuously 10 seconds, the water pump and the compressor will be OFF permanently and 
OFF/ON control panel LED will blink (H62 error occurs). 

  When error happens, the power has to be reset to clear the error. 

  If there is no error indication, the water pump shall be continuously running. 

  The water pump will remain ON when compressor OFF due to thermostat OFF setting is reached. 

  Water pump must always operate during heating mode, deice operation and also during heater ON condition. 

  Water pump will stops 15 seconds after the unit stops operation. 
 

t ≥ 9 min

YES

NO

NO

Flow

S/W

Status

tc < 1min

NG

STOP Water pump

OK

Water Pump Control

ON Water pump

YES

ERROR display at

Control Panel

ERROR reset by

power reset

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

62 

 

+

Power for drive

DC280-373V

-

+

Power for control

DC15±10%

Control Signal
DC0V-DC6V

Feedback Speed
(puls signal)
4puls/rotation

-

Pump

67

5

6

4

2

1

3

VDD

GND

VCC

FG

VSP

 

 

Control signal is analog voltage (DC0V-6V) generated by microcomputer PWM port. 
Microcomputer can change analog voltage by changing PWM duty. 

 

  Set water pump speed to adjust the water flow rate.  
 
Depend on the hyraulic system pressure loss and type, the water flow rate can be adjusted by control panel. 

1  Press SERVICE button for 5 seconds. 
2  Press 

▲ 

button to enter menu S02 and press SET button. 

3  Press SELECT button then press 

▲

/

▼

 button to change SPEED and press SET to confirm. 

4  Press OFF/ON button to quit setting. 

 

0

10 13 20

30

40

50

60

70

1

2

3

4

5

6

7

110

120

130

100

90
80
70
60
50
40
30
20
10

0

WATER FLOW RATE (L/min)

EXTERNAL STAT

IC PRESSURE 

(kPa)

N

O

T 

AP

PL

IC

AB

LE

 R

AN

GE

N

O

T 

AP

PL

IC

AB

LE

 R

AN

GE

 

 

 
Note: 
* Before adjust the water flow rate, make sure that the total water volume in the installation is minimum 50 litres for 
heating side. 
* Please ensure the minimum flow rate is not less than 13l/min and not more than 50l/min. 

63 

  Basically pump speed feedback is control by micon. 

  When pump speed is below low limit or over high limit for a few seconds, micon detect pump error and 

system is stopped. 

  Error detection conditions: 



  Current pump speed < 1000 rpm or 



  Current pump speed > 6000rpm for 10 seconds. 

  Control contents: 



  When error occurs, water pump, heating and heater is stopped for 30 seconds then restart again (Retry 

control). 



  When micon detect error again, system is stopped and error code [H20] is displayed at control panel.  

 

 

Purpose 
Circulate and fill the piping with water during installation time 

  Water pump only circulation can be set from the control panel SERVICE S/W when the operation is in 

Standby Mode. 

  Press the SERVICE S/W for continuous 5 sec to enter Service Mode. 

  In Service Mode, select SR: 02 and press SET S/W to start water pump only operation. 

  3 way valve turn OFF and 2 way valve turn ON. 

  Water pump will stop operation when H62 is triggered. 

  Press the OFF/ON button to stop the water pump only operation. 

 

Purpose 
Ensure the pump down operation when relocating or disposing of the unit. The pump down operation will extract all 
refrigerant from the piping into the outdoor unit. 
 
Controls: 

1  Press the SERVICE S/W for continuous 5 seconds to enter Service Mode. 
2  In service mode, select Sr: 01 and press SET S/W to start Pump Down operation. 
3  There will be no low pressure error and freeze prevention judgement during Pump Down operation. 
4  3 ways valve will shift to room side and 2 ways valve will turn ON. 
5  Press OFF/ON button to stop the unit. 

1  The water flow switch serves as an overload protector that shuts down the unit when the water level is 

detected to be low. 

2  Detection is Lo (0 V) when there is no water flow, and detection is Hi (5 V) when there is water flow. 

 
 

64 

1  When water pump is ON, the system will start checking flow switch status (ON/OFF). 
2  If the flow switch ON for 10 seconds, the system will check on the water inlet temperature for 10 seconds. 

If the water inlet temperature not exceeds 80°C, the water pump shall be continuously running with normal 
mode. 
If the water inlet temperature exceeds 80°C for continuously 10 seconds, the water pump will be OFF 
immediately. 

3  After water pump OFF for more than 10 minutes, it will be ON back and the indoor unit safety control 

checking is restarted. 

 

YES

YES

YES

NO to normal mode

10s

Flow SW ON?

Pump ON

Pump OFF

>10 mins

Water In > 80°C for 10s

 

1  When the power supply is cut off during the operation of Air-to-Water Heatpump, the compressor will re-

operate after power supply resumes. 

 

LED 

Operation 

Color 

Green 

Light ON 

Operation ON 

Light OFF 

Operation OFF 

Note: 

  If Operation LED is blinking, there is an abnormality operation occurs.