sauter NRT407, Руководство пользователя

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NRT407 manual Part III Configuration 39
Chapter 10 Actuators
NRT can be used with four types of actuators:
•
Analogue 0…10 V actuators
•
Thermal actuators
•
3-point actuators (Increase/Decrease actuators)
•
On/Off spring return actuators
On units without display, it is possible to select if thermal or analogue actuators will be used
via the DIP switches. For other actuators and NRT models, the actuator type is set via NRT
tool or, for controllers with a display, in the parameter menu.
Analogue actuators
The following output signals can be set for analogue actuators:
•
0…10 V (FS)
•
2…10 V
•
10…2 V
•
10…0 V
Thermal actuators
When thermal actuator control has been selected, it is controlled digitally with time
proportional pulses via output UO1 and UO2. By pulsing, the opening degree of the actuator
(and its valve) is varied. The period time (in seconds) is the sum of the on and off output
times on the output. The period time is FS=60s. The controller varies the on and off output
times proportionally depending on the output signal demand to the actuator.
3-point actuators
For 3-point actuators (increase/decrease actuators, -T-models), two digital outputs are used
for controlling one actuator, one output to open the actuator and one to close it. You can
configure the run time (in seconds) for the different actuators (FS=120 s). The program
calculates the position of the actuator (0…100 %) and sends an increase or decrease signal
when the controller output signal deviates more than the set neutral zone (FS=2 %) from the
calculated position.
On/Off spring return actuators
When On/Off spring return actuator has been selected, the functionality is similar to a
thermostat function. This will be relevant only in control modes Heating, Heating/Cooling
via change-over, Heating/Cooling and Cooling. Selecting this function will not be possible if
any other control mode has been selected.
A hysteresis is used when the outputs are On or Off.
In heating mode, the temperature will be permitted to fall below the setpoint, minus the
hysteresis, before the actuator opens. The actuator will then remain open until the
temperature rises above the setpoint.