Campbell CVF4 Instruction Manual - page 15
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Instruction Manual - CVF4
2.5 Electrical connections
The CVF4 has a 4 wire cable for connecting the 12 VDC to the ventilator and heater. The ground is common for the ventilator,
heater and the tacho output.
The tacho output (Ut in diagram below, pin 4, yellow wire) provides a 5 Volt signal that gives two pulses per revolution. It can
be connected to a data logger to (remotely) check proper operation of the CVF4. The tacho output uses the same power supply
ground (pin 3, green wire).
The nominal speed is 4400 rpm, resulting in 8800 pulses per minute which equals 146 Hz on the tacho output.
Changes often indicate pollution of the filter (higher frequency), or mechanical problems with ventilator (lower frequency).
If sufficient power is available it is advised to use the heater in combination with the ventilator even in warm climates. The
heater will prevent deposition of dew in the morning.
VENTILATION UNIT CONNECTION
ANSCHLUSS • RACCORDEMENT • CONEXIÓN
Ground
Erde
Terre
Tierra
Red
+ Ventilator
Rot • Rouge • Rojo
+ Ventilator
+ Ventilateur
+ Ventilador
Wire
Kabel
Fil
Cable
Function
Funktion
Fonction
Función
Yellow
Gelb • Jaune • Amarillo
Connect with
Anschluss an
Relier à
Conectar con
Housing
Gehäuse
Boîte
Cubierta
Shield
Abschirmung
Protection
Malla
1
4
Green
Grün • Vert • Verde
3
Blue
+ Heater
Blau • Bleu • Azul
+ Heizung
+ Chauffage
+ Calentador
+12 VDC @ 0.5 A
5 V tacho output
+12 VDC @ 0.4 A
+ Hi
2
Power supply
12 VDC ground, tacho ground
Spannungsversorgung
Alimentation
Fuente de alimentación
Erde
Terre
Tierra
* Connect to ground if radiometer not grounded
Mit Erde verbinden, wenn das Radiometer nicht geerdet ist
Reliez à la terre si le radiomètre n'est pas connecté
Conectar a tierra si el radiómetro no lo está
VENTILATOR
1
2
3
4
R1
R2
R2
+12 Volt
0 Volt
R1
Ut