Riello Array AR 399 SE Installation, Operation And Service Manual page 35

− CH Mode 1 - Room Themostat & Outdoor Reset: this mode
requires an outdoor sensor, in addition to the room ther-
mostat. The system functions similar to CH mode 0, except
the Tempererature Setpoint is automatically calculated
based on the Reset curve. Curve parameters are available
on the Reset curve screen (through the Settings screen).
Fig. 32 Reset Curve screen
By adjusting the parameters on the screen, the reset curve will
modify its shape and sloper to meet the needs of the specific ap-
plication.
°C °F
93 200
Reset Curve
82 180
Design Boiler
71 160
60 140
49 120
38 100
Reset Cuve
27 80
Boiler Mild
Weather 16
60
20
°F
-6
°C
Reset Curve
Outdoor Design
Fig. 33 Reset Curve
− CH Mode 2 - Full Outdoor Reset: just an outdoor sensor
is required. The Temperature Setpoint is still automatically
calculated based on the Reset curve. If a room thermostat
is installed, it activates the Night setback function (setpoint
reduction during the night) but it does not affect the CH
demand.
− CH Mode 3 - Permanent Demand: the system works simi-
larly to Mode 0. Supply temperature is kept at the Setpoint
level steadily. If a room thermostat is installed, it activates
the Night setback function (setpoint reduction during the
night) but it does not affect the CH demand. Module pump
is always ON.
− CH Mode 4 - Analog Input to Setpoint: the Temperature
Setpoint is given by an analog signal provided by a remote
control such as a Building Management System or a system
controller. A heat demand will be generated by an input of
1.5 Volts or higher. Modulation will occur between 2 and 9
Volts. Voltage below 1 Volt will shutoff any demand.
Ver X.X.XX
Reset Curve Boiler
Maximum
Reset Curve Boiler
Minimum
OUTDOOR TEMP. (°C/°F)
40 60 80 100
4 16 27 38
1) Reset Curve Outdoor Mild Weather
2) Warm Weather Shutdown
NOTE: after selecting CH mode 4, enable it either:
jumpering "Enable/Disable" pins (#11-12) on Terminal strip
−
or
− accessing the list of parameters through the Service display
and move parameter #124 from 1 (default value) to 0.
CH Setpoint
Maximum
CH Setpoint
Minimum
1.0
OFF ON/OFF
Hysterese
Fig. 34 10VDC Control mode
NOTE: Scale the analogue signal to match the system
temperature requirements. scaling the temperature
range using the boiler parameters will artificially limit the
maximum operating temperature of the boiler.
Domestic Hot Water (DHW) function can be enabled using the pa-
rameter 35 on Service display.
Three modes are available:
− DHW mode 0 - DHW function disabled.
− DHW mode 1 - Tank with sensor: hot water is stored in
a tank where the temperature is measured by a sensor.
Either a pump or a 3-way valve can be used to switch to
DHW mode. When the DHW demand is on, the boiler is PID
modulated to achieve the supply temperature made by the
DHW store setpoint increased by an adjustable extra tem-
perature. DHW store setpoint is manually set on the CH/DHW
Setpoints screen (through the Settings screen).
Fig. 35 CH/DHW Setpoints
35
COMMISSIONING
1.5 2.0
Voltage
ON
Ver X.X.XX
9