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3.5.4 Pump control
The control is able to manage one or two pumps
inside the unit. The pump is activated if the spe-
cific
parameter
is
configured
(PUMPCONFIG)
and if the unit is in heating or cooling mode.
The start-up delay value of the compressor, with respect to
the pump, is set to 1 minute (default) but it can be extended
to 15 minutes. In this case the pump will work with compres-
sor stopped for a time equal to the set delay value.
If the unit stops the pump stays ON for 20 seconds.
However, if the unit changes mode (heating/cooling), the
pump carries on working. The pump instead stops if the
unit is in lockout condition due to an error, unless the an-
ti-freeze protection is triggered. Moreover, it can be started
if the electric heating element of the plate exchanger is trig-
gered. Refer to the specific paragraph for pump control de-
tails in case of installation of two machines in Master/Slave
configuration.
3.5.5 Control point
The control point is the water temperature value that the
unit must reach. The exchanger entering water temperature
is already set while the leaving temperature can be set, ho-
wever only by the Technical Support Service. The control point
value is calculated as:
Control point: Active seReset
3.5.6 Active setpoint
Up to two setpoints can be selected in cooling mode and two
in heating mode. Usually, the second value is matched to pe-
riods in which the unit is not active.
This value can be selected:
• from the control panel (GENUNIT menu).
• from dry contacts
• from CCN
• through timer setting
The tables below list the selections available according to the
control type (from panel or in remote). The parameters listed
are:
• Local setpoint selection: the value to be entered
is in the GENUNIT menu, LSP_SEL parameter.
• Time schedule 2: Select the SCHEDULE sub-menu to access
the CONFIG menu.
• Setpoint selection contact: this parameter identifies con-
tact status (open or close).
Heating / cooling
operation mode
Local
setpoint
selection
Calendar 2
status
Active setpoint
Cooling
sp 1
-
Cooling setpoint 1
Cooling
sp 2
-
Cooling setpoint 2
Cooling
auto
occupied
Cooling setpoint 1
Cooling
auto
unoccupied
Cooling setpoint 2
Heating
sp 1
-
Heating setpoint 1
Heating
sp 2
-
Heating setpoint 2
Heating
auto
occupied
Heating setpoint 1
Heating
auto
unoccupied
Heating setpoint 2
OPERATING MODE: FROM CONTROL PANEL
PARAMETER STATUS
Heating / cooling
operation mode
Contact setpoint
selection
Active setpoint
Cooling
sp 1 (open)
Cooling setpoint 1
Cooling
sp 2 (closed)
Cooling setpoint 2
Heating
sp 1 (open)
Heating setpoint 1
Heating
sp 2 (closed)
Heating setpoint 2
OPERATING MODE: REMOTE PANEL
PARAMETER STATUS
3.5.7 Reset
The Reset parameter aim is to change the active setpoint va-
lue (in cooling mode it increases the value while in heating
mode it decreases it) in order to reduce the capacity reque-
sted to the machine. The change of this value is a conse-
quence of a drop of the outside temperature value or drop
of the temperature differential in the plate exchanger and
is aimed at improving machine performance. As one might
notice from the graph below, the reset value is a curve where
the values can be set from the control panel by accessing the
RESETCFG menu. Parameters to be set are the following:
• Maximum reset value (A)
• Outside
temperature
value
(or
variation
of
exchanger temperature) for which the reset value is =0 (B)
• Outside
temperature
value
(or
variation
of
exchanger temperature) for which the reset value is ma-
ximum (C)
Example of reset value trend with unit in cooling mode.
3.5.8 Demand limitation
This function is used to limit unit power consumption. Basically,
the unit cannot exceed a setpoint limit value that can be set from
the control panel accessing the SETPOINT menu. In this case,
the dry contacts will be used.
3.5.9 Capacity control
With this function, the machine adjusts the compres-
sor so that the temperature of the exchanger leaving wa-
ter is kept to the set value (setpoint). The control pa-
nel constantly measures the temperature of the unit
entering and leaving water as well as the difference
of temperature with the setpoint. Based on the read values,
it decides to change machine capacity by acting on the com-
pressor. If the compressor is started too frequently or is kept
Reset value
Outdoor temperature (OAT)
Heat exchanger delta T
% Building load
A
°C
3
100
D
B
C
10
3.0
20
5.0
°C
0
%
