Riello TAU Unit 50 Installation And Maintenance Manual page 56

COMMISSIONING AND MAINTENANCE
Mode 4
(Set-point adjustment based on a 0-10V analogical input)
The parameters that control this mode are the following:
Par.
Description
No.
Sets the minimum delivery temperature value in heat-
110
ing mode (Par. 1) = 4.
Sets the maximum delivery temperature value in heat-
111
ing mode (Par. 1) = 4.
The operation set-point is adjusted on the basis of the following
curve:
Temperature
(°C)
Par. 111
Par. 110
0 1.0
ON/OFF
OFF
Hysteresis
The maximum and minimum set-point values are defined re-
spectively by Par. 111 and 110.
When the value of the input voltage is greater than 1.5V, the re-
quest is activated (at minimum setpoint).
For voltage values from 2 to 10, the setpoint varies linearly from
the minimum to the maximum value. If the voltage falls from 10V
to 2V, the setpoint falls linearly and keeps the minimum value
between values 2 and 1V. For values lower than 1 V the demand
ceases.
9
To activate the 0-10V analogue input it is necessary to disa-
ble the input of the room thermostat (TA). To do this, set the
Par. 124 = 0 or else insert a jumper at the TA input (short-cir-
cuit the terminals 15-16).
Modulation
1.5 2.0 10
ON
Voltage (V)
Mode 5
(Adjusting the power based on an analogue input 0-10V)
In this operating mode, the power of the thermal unit (fan
speed) is adjusted by an incoming analogue signal supplied by
an external management system.
The parameters that control this mode are the following:
Par.
Description
No.
Defines the number of fan rpm at max. power (it
92
depends on the model and is defined at Par. 98).
Defines the number of fan rpm at minimum power (it
93
depends on the model and is defined at Par. 98).
The power of the thermal unit is adjusted based on the follow-
ing curve:
Temperature
(°C)
Par.92
OFF
Par.93
0 1.0
ON/OFF
OFF
Hysteresis
The maximum and minimum values of the number of revolu-
tions of the fan are set by parameters 92 and 93 respectively.
When the value of the input voltage reaches or is higher than
1.5V, the request is activated (Par. 93).
The fan speed (thermal unit power) varies linearly in a range
between 2.0 and 9.0 Volts.
The fan speed varies linearly from minimum to maximum value
for voltages between 2.0 and 9.0 volts.
If the voltage falls from 9.0 to 2.0, the control point falls in a
linear manner and maintains the minimum value between 2.0V
and 1.0V. For values below 1 V demand is interrupted.
9
To activate the 0-10V analogue input it is necessary to disa-
ble the input of the room thermostat (TA). To do this, set the
Par. 124 = 0 or else insert a jumper at the TA input (short-cir-
cuit the terminals 15-16).
56
ON
Modulation
1.5 2.0 9
ON Voltage (V)