MAXA HWA1-A 0140, Manual

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HWA1-A
Air/water chillers with axial fans
19
14.5.2 ADJUSTABLE SETPOINTS
Setpoint type Setpoint (summer/winter) Summer Winter
First setpoint (°C) Coo/Hea 7 (5÷18) 45 (35÷57)
Second setpoint (°C) Co2/He2 18 (7÷23) 35 (25÷45)
For setting the setpoint from the conboard control panel, you can use the SET button.
The second setpoint is greater than the first setpoint in the summer and lower in the winter:
•
in the summer: T2 >= T
•
in the winter: T2 <= T
14.5.3 COMMUTATIONS
The commutation sequence from first (normal) set-point to the second setpoint:
•
in the summer: Commutation of the 3-way valve only when the second set-point -5°C is achieved.
•
in the winter: commutation of the 3-way valve only when the second set-point +5°C is achieved (at any case after 5min
from setpoints modification, the commutation of the valve will be carried out)
The commutation sequence from second set-point to the first setpoint:
•
Commutation of the 3-way valve
•
Modification of the operating setpoint after a lap of time equal to the required time for opening of the 3-way valve.(default
b04=30s
from maintainer menu)
14.6 MANAGEMENT OF A SECONDARY CIRCULATOR (RELAUNCHING PUMP)
As an alternative to the double set-point function, it is possible management of a secondary or relaunching circulating pump to
serve the plant system.
An ambient thermostat must be appropriately configured (NC state) connected on the terminals DI3E-DI3E.
−
Thermostat contact normally open
→
the secondary circulator will be activated;
−
− Thermostat contact normally closed
→
the secondary circulator is off with a delay given by P02 (post-pumping)
To enable this function, enter at the parameters menu PRG
→
PSS
→
PRG
→
(introduce the maintainer password)
→
PRG
→
PAr
→
PRG
→
CnF
Parameter Unit Value Description Terminals Note
H57 Num 19 Digital input for thermostat call
ID3E
ID3E
-
H90 Num 43 Under voltage output for secondary circulator
DO5E(phase)
DO5NE(neutral)
Under voltage output single phase
230Vac, 50Hz, 5A resistive, 1A
inductive to connect relay coil for
obtaining a free contact.
The thermoregulation of the pump is depending on the thermostat call.
With Heat Pump in Off, the secondary circulator will stop operation independently than the thermostat call.
14.6.1 ANTIFREEZE CONTROL OF PLANT SECONDARY PUMP
If the remote plant sensor is configured, there is an antifreeze control on the secondary circulator.
If the regulation temperature is too low and the pump is off, it will start automatically to operate in case of:
Pa
P04: Setting parameter of pump operation in antifreeze cycle
Pa P05: Pump hysteresis in antifreeze cycle
15 SIGNALIZATIONS ’ MANAGEMENT
On the DO5E/DO5NE (Parameter H90 ), you can set a 230Vac signal output by setting the following user parameters by entering
the installer password in the controller situated on the front panel.
ON
OFF
Sensor of regulation
P04 Pump antifreeze setting
P05