sauter NRT407, Руководство пользователя

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44 Part III Configuration NRT407 manual
Chapter 12 Special functions
Change-over function
Change-over is a function for installations with 2-pipe systems. It makes it possible to use
the same pipe for both heating and cooling, depending on requirements during for example
the summer (cooling output) and the winter (heating output).
Control modes To activate the change-over function, control modes "Heating or Cooling via change-over"
or "Heating/Heating or Cooling via change over" needs to be configured.
The input can be either of the type analogue PT1000-sensor or a closing contact connected to
a digital input (FS=PT1000-input).
Change-over digital When using a digital signal input (potential-free contact), closing the contact will activate the
change-over function and set the heating output, UO1 alt. DO2/DO3, to cooling. On open
contact, the change-over function will set the heating output to heating.
Change-over analogue In this mode, the change-over function will measure the difference between the room and
media temperature. As long as the heat valve is more than 20 % open, or every time a valve
exercise is performed, the difference between the media and room temperature will be
calculated. If the temperature difference is lower than the configured value (differs for
Heating and Cooling mode), the control mode will change. The factory settings for the
difference between Heating and Cooling change-over are:
•
Change from Heating to Cooling = 4K
•
Change from Cooling to Heating = 3K
This setting may be changed using parameters number 9 and 10.
Forced ventilation
All NRT controllers have functionality for forced ventilation. All controllers except
NRT407F902 have a digital output for controlling a forcing damper to increase the airflow to
the room. This output is always activated in operating mode Bypass.
When control mode “Heating/Cooling with VAV-control and forced supply air function” is
active, the cooling output is used to control the forcing damper. When forced ventilation is
active, the cooling output is set to full cooling, regardless of what the controller output signal
is.
NRT407F901 can select whether the forced ventilation output should be a 0…10 V analogue
output or a 24 V digital output (parameter 22).
Condensation detector
Special input CI There is a special input (CI) on all NRT controllers. This input is intended for Sauter
condensation detector, EGH102, and functions internally as a digital input, i. e. condensation
or no condensation.
When the condensation detector is activated, the cooling control is blocked and the controller
is set in neutral position. When condensation ceases, the controller will start controlling from
the neutral position.
Window contact When window contact has been configured, the controller is set to normal mode on closed
window. On open window, the controller is set to off mode, the heating and cooling outputs
are set to 0 V and the frost protection function is activated.