Grant Aerona 3 HPID10R32, Instructions Manual, Page: 37 / 100

Page 37 Section 8: Operation
! CAUTION !
The water flow rate must be sufficient to achieve an 8K
difference between the flow and return water temperatures.
8.3.7 ADDITIONAL WATER PUMP
Parameter 5148 can be utilised to use an additional water pump.
Parameter 4220 can be used to set the desired type of pump
operation as follows:
1. Depending on main water pump setting
2. Depending on main water pump setting but always OFF when
DHW mode is activated
3. Always ON apart from if any alarms are active or if the heat
pump is in OFF mode
Option 2 is recommended for the majority of applications.
The connection between neutral and terminal 48 (Pump1) is limited
to 1 amp, therefore a relay must be installed if an additional water
pump is used. Refer to Figure 8-9.
Table 8-6: Additional water pump parameters
Level
Parameter
Function description
Display and input value
Remarks
Group Code Default Min. Max. Unit
I 51 48
Terminal 48
0=disable
1=additional water pump
0 0 1 -
I 42 20
Type of operation of additional water pump
0=disable
1=depending on main water pump setting
2=depending on main water pump setting but always OFF
when the DHW mode is activated
3=always ON, apart from if any alarms are activated or if the
heat pump is in OFF mode
0 0 3 -
For details of how to access the parameter settings, refer to Section 9.3.
Additional water pump
230V 50Hz
P
Terminal PCB
Dehumidifier
Neutral
EHS
45
46
47
48
49
N
41
42
43
44
Electric
heater
Heating
Cooling
mode
output
Alarm
Pump1
Pump2
Figure 8-9: Additional water pump
! NOTE !
In reference to option 3 in Section 8.3.7 (and parameter 4220
in Table 8-6), ‘OFF’ mode means there is a power supply to
the heat pump but there is no heating or hot water demand.