Domestic Hot Water Heat Pump Service Manual
34
Hygrostat Function
– fan speed control
The air flow is automatically adjusted depending on the ambient air conditions or by manual
adjustments.
The fan constantly runs changing the speed level depending on the 0~10V input signal from
external humidity sensors, CO
2
sensors or human interface panel:
When the input signal is from 0 to 3.3V, the fan switches to minimum speed level (from D5)
When the input signal is from 3.3 to 8V, the fan switches to medium speed level (from D4)
When the input signal is from 8 to 10V, the fan switches to high speed level (from D3)
Humidity / CO2 Sensor
Human Interface
Humidity / CO2 Sensor
Receiver
Room 1
Room 2
B
LU
B
(D
-)
L
N
L
N
0V
0V
L
L
0V
0~
10V
Input
BT3
EB1
0V
0V
0V
FM
BT2
BT1
0V
0V
L
N
PE
230VAC ~ 50Hz
0V
A
(D+
)
0V
B
LU
0~
10V
P
W
M
YE
L
High pressure switch.
Compressor STOP when
Pd ≥ 2.0MPa
Solenoid valve.
Solenoid ON for 2 min
before compressor
starts and during
system defrost
B
R
N
B
LK
N
BLU
BLK
BRN
B
R
N
B
LU