7.3.1 Main water pump
7.3.1.1 Continuous operation “Always ON”
7.3.1.2 Sniffing operation “Sniffing cycle”
7.3 Water pump management
Fundamentally, ON/OFF of the Main water pump links to ON/OFF of the compressor, but the setting ON/OFF of
the pump during compressor OFF states, due to reaching the Room set point shall be set in the following
parameters;
Always ON, apart if any alarms are active or if the HP unit is in OFF mode
ON/OFF based on Buffer tank temperature
ON/OFF based on Sniffing cycle
If the Buffer tank temperature probe is enabled, the Main water pump turns ON if the Buffer tank temperature is
lower than Outgoing water set point (Fixed or calculated by Climatic curve) – Hysteresis, in Heating mode, or
higher than Outgoing water set point (Fixed or calculated by Climatic curve) + Hysteresis, in Cooling mode. When
the Buffer tank temperature reached the set point (Fixed or calculated by Climatic curve), the main pump turns
OFF.
When the HP unit is set to “Heating” or “Cooling” mode (i.e. not in standby) the Main water pump will always
remain ON.
When the HP unit is set to standby, the pump will remain OFF and will only be started in the conditions described
in paragraph on 7.4 Frost protection.
In order to minimise energy consumption, the Main water pump can be configured to start only when there is
demand from the temperature controller.
The pump will be activated periodically, for a time set by parameter. Five seconds before the cycle ends, if the
Outgoing water temperature is lower than “water set point – hysteresis”, in Heating mode, or higher than “water
set point + hysteresis” in Cooling mode, the compressor will be activated and the pump will remain ON. When the
compressor stops, the pump will continue running for a time set by parameter, after which it will be switched OFF
and will repeat the Sniffing cycles.
The interval between one Sniffing cycle and the next is set by a parameter.
Note1: the “Sniffing cycle” is allowed only for space Heating/Cooling. If the HP unit is working to produce DHW the
Main water pump has to run continuously.
Parameters
Level
Parameter
Function description
Display & Input value
Remarks
Group Code
Default
min.
Max.
Unit
I
42
00
T ype of configuration of Main water pump.
0=Always ON
1=ON/OFF based on Buffer tank temperature
2=ON/OFF based on Sniffing cycle
0
0
2
-
To be set to
the following
combinations.
Par5111=0
→Par4200=0 or 2
Par5111=1
→Par4200=0 or1 or 2
I
51
11
T erminal 11-12 : Buffer tank temperature probe
0=disable
1=enable
0
0
1
-
65
7. Unit Management
Summary of Contents for AEYC-0639U-CH
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