Azbil HY7045T1000 - Signal Wiring and Noise Suppression

17
AB-7521
z
Notes for wiring power
When supplying power to the sensor via the AC transformer (24 V AC power supply) , be sure to follow the
instructions below.
IMPORTANT
•
If the common line (-) of the controller is non-insulated type, do not share the AC transformer (24 V AC
power supply) for the humidity sensor or temperature/humidity sensor.
•
If the AC transformer (24 V AC power supply) is shared, a loop will be made in the circuit and the sensor
may fail.
AC transformer
Model HY7045T/Model HTY7045T
Model HY7045T/Model HTY7045T
24 V AC100 V AC
Controller
＋
－
Blue
(+)
Gray
(-)
Black
(⊥)
Brown
(～)
Blue
(+)
Gray
(-)
Black
(⊥)
Brown
(～)
＋
－
INCORRECT
Figure 21. A loop is made in the circuit
•
If the AC transformer (24 V AC power supply) is shared, and if the wires are incorrectly connected between
the

brown wire (~) and the

black wire (
┴
) or between the

black wire (
┴
) and the

brown wire
(~) as illustrated below, a short circuit will be made in the circuit through the common line and the sensor
may fail.
AC transformer


Model HY7045T/Model HTY7045T
Model HY7045T/Model HTY7045T
24 V AC100 V AC
Controller
＋
－
＋
－
(+)
Gray
(-)
Black
(⊥)
Brown Blue
(～)
(+)
Gray
(-)
Black
(⊥)
Brown Blue
(～)
INCORRECT
Figure 22. Incorrectly wired
z
Note for signal wiring
Because of the induction current owing from the humidity sensor or the temperature/humidity sensor to the
controller input circuit or an inadequate time constant of the controller, the system may be affected by an
electrical noise.
In order to suppress noise, check the following items.
•
Use a controller, which receives signals from the sensor, with a low pass filter (40 dB or higher noise
rejection ratio in the normal mode) .
•
If the noise rejection ratio is insu󰀩cient, provide an isolator on the controller input signal.
No problem will occur for connecting the sensor to Azbil’s controller.
IMPORTANT
•
When the sensor gets faulty, a room may be over humidied due to decline of its output.
Please take a countermeasure at the controller side.
•
Corrosive gas, organic solvent, and other chemicals contained in the atmosphere can cause measuring
error of the sensor, shorten its service life, or damage it.
if the sensor is used in an environment di󰀨erent from the ordinary air, please contact Azbil Corporation.