Controlli W500H, Руководство пользователя

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Rev. d 01/1 37 DMP052E
EXAMPLE 3 :
RETURN AIR SYSTEM WITH DAMPER MANAGEMENT ONLY FOR TEMPERATURE, ROOM
TEMPERATURE AND HUMIDIFICATION
In a return air system, the differential comparison between outside and inside temperature to
control dampers, room temperature control with cooling/heating bat limit function (anti-frost
or max temperature) on any digital input.
OPERATION
The controller carries out time control, by PI action, on room temperature on return (2 sensor), by
driving the valve (4) on heating/cooling coil. It controls with “direct” action (summer) or “reverse”
action (winter) depending on the changeover (6) read on digital input D.i.2. In winter time, room
humidity (transmitter 3) is maintained at the set point value through On/Off humidification (9).
Outside air dampers (inlet and exhaust) and the return air damper are driven with only one
analogue output and the apposite direct/reverse set concerning the relevant actuators (outside
max opening = minimum return air). If the outside temperature (sensor 10) is lower than inside one
(2 sensor) and it is winter time, the inside air will have priority giving the possibility of minimum
opening. Vice versa in summertime.
ModBus supervision is possible.
Frost protection: in case of heated fluid lack or of faulty control, if the anti-frost thermostat (5)
detects a temperature lower than the set value, the controller stops the fan and closes the outside
air and air-exhaust damper and contemporarily opens the of return air damper.
Obstructed filter : the pressure switch (7) signals the presence of obstructed filter if the differential
pressure before and after the filter, increases over the set value.
Possible Variants: outside compensated set on SC sensor for heating/cooling loop (Ao1).
In summertime, in the control loop, the “Max Humidity limit” function is started on proportional valve
(4) depending on 0-100% signal coming from SH input (Humidity transmitter) and on set and
proportional band of humidity limit set. If the cooling request due to limit loop (de-humidification) is
higher than the temperature one, the controller will give priority to the de-humidification request, by
cooling more in order to condensate more humidity on supply.