Basic Principles And Setting Options For "Absolute Humidity Difference Control; Note On Setting The Output Variable For The Measured Humidity Value; Required Components; Sensor Assembly - Helios EUR EC Instructions D'installation Et D'utilisation

Installation and Operating Specification EUR EC
13.4

Basic principles and setting options for "Absolute humidity difference control"

13.4.1

Note on setting the output variable for the measured humidity value

The AFS 0-10V sensor has three possible physical output options:
1. Factory setting
– MV = Mixing ratio in g/kg (mass of water vapour per mass of dry air). The humidity difference
control uses this humidity value to most accurately determine the drying potential of the outside
air.
2. Not recommended
– a.H.. = Absolute humidity in g/m
setting leads to inaccurate determination of the drying potential of the outside air, which in
individual cases can even lead to an increase in the room humidity.
3. Not permitted
– r.H. = Relative humidity in %. This humidity value is unsuitable for use of absolute humidity
difference control and may not be set. It can result in damage to the building due to a sustained
increase in room humidity.
13.4.2

Required components

1 x EUR EC, item no. 1347 002
2 x AFS 0-10V, item no. 06532 001
• Use at operating temperature -30 to +70 °C (no direct solar radiation)
• Output 1 = Temperature -20 to +80 °C (not required for control)
Output 2 = MV mixing ratio 0 - 50 g/kg
•
Relative humidity tolerance +/- 3 % (40 - 60 %) at 20 °C, otherwise +- 5 %
•
• DIP switch: 101000
Protection class: IP65
•
13.4.3

Sensor assembly

The sensors have the protection rating IP65 and may be installed outdoors and in humid rooms. They
may not be exposed to direct solar radiation.
• The first sensor is installed outside. It checks how dry the outside air is. Evaluation is carried out on
the EUR EC via the analog input "E2".
The second sensor is installed indoors in the room to be dried. Evaluation is carried out on the EUR
•
EC via the analog input "E1".
• The 24 VDC supply comes from the EUR EC.
13.4.4

Functionality

The "AFS 0-10V" sensor measures the relative humidity and temperature, and uses these to calculate
the required MV mixing ratio necessary for control. The mixing ratio 0 - 50 g/kg is output in 0 - 10 V
(factory setting).
The first sensor is installed indoors and the second sensor outdoors.
The "EUR EC" control unit evaluates the two 0 - 10 V signals from the relevant sensor (AFS 0-10V).
The 0 - 10 V output value from the indoor room sensor is compared with the 0 - 10 V output value from
the sensor outdoors.
The EUR EC outputs an analog control signal of 0 - 10 V depending on the difference in the two
sensors. The difference value to be controlled and a control range can be set by entering parameters
in the EUR EC
The difference value specifies the variation from which control starts.
•
The control range specifies the final value up to which the 10 V output is achieved.
•
Example:
Set difference value = 0 corresponds to 0 g/kg
•
Control starts working at a variation of >0 g/kg.
•
Slow modulation:
• Sensor output 0 - 50 g/kg.
Control range 50 corresponds to an output of 10 V.
•
Thus 0 - 50 g/kg corresponds to control of 0 - 10 V.
•
• To achieve an output value of 10 V, the difference must be 50 g/kg.
L-BAL-E274-GB 1914 Index 003
3
(mass of water vapour per room volume of humid air). This
Part.-No.
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Enclosure