Probe Wiring; 4/20 Ma Signal - AERMEC KTU Mode D'emploi

time constant
(temp.)
time constant
(humidity)
classifi cation according to protection against electric shocks
PTI of the isolation materials
period of electric stress of the isolating parts
level of environmental pollution
resistance category to heat and fi re
categ. (immunity against overvoltage)
6.4.

PROBE WIRING

To perform wiring, use a shielded
multi-polar cable with 3 to 5 wires,
depending on models. The maximum
section of the wire envisioned by the
clamps is 1.5 mm .
2
0/1 Vdc signal: with active outputs
models (not NTC res.) configured in
voltage, it is advised to consider the
EXAMPLE:
cable length (m) cable section (mm
30
30
6.5.

4/20 MA SIGNAL

For distances over 30 m, whenever the
system allows it, it is recommended to
select output in current.
The maximum remote control distance
for the output in current is 200 m. In
the case of alternating current it is
indispensable to use cable with section
of 1.5 mm2 in order to reduce the
noise due to the power supply current.
This noise can cause instability of
measurements in some cases. This can
be eliminated with direct power supply
or with an additional power supply as
shown in the figure at the side.
!
WARNINGS:
the transformer does not have to
be connected to earth and can be
positioned in the regulator control
board.
The connection cable will be multi-
polar with 4 or 5 wires. In this situation,
voltage drop on the cables: the effect
of the drop on 1 mm
variation of 0.015 °C per metre of cable
(0.015 °C m/mm
2
measurement and a variation of 0.015%
R.H. per metre of cable (0.015% R.H. m/
mm2) on the humidity measurement.
An example is given below that clarifies
) TEMPERATURE error (°C)
2
0.5 0.9
1.5 0.3
Bn
Bm
(AVSS) M
230 Vac
power supply current does not flow in
the M - AVSS connection. In installation
with several probes, each must be
powered by its own transformer.
With this configuration, the maximum
remote control distance is 100 m.
In the case of great distances, for
300 s in still air
60 s in ventilated air (3 m/s)
60 s in still air
20 s in ventilated air (3 m/s)
can be integrated in Class I and II appliances
250 V
long
normal
category D (for box and lid)
category 2
section is a
2
) on the temperature
HUMIDITY error (% R.H.)
0,9
0,3
+
TRA12/TRA24
12/24 Vac
TRANSFORMER
the calculation of the variations, which
give the temperature and humidity
error. 0/10 Vdc signal: present only in
ASWC112000/ASWC115000 models.
models with two active outputs, it is
also preferable to avoid the mixed
voltage-current configuration of the
two outputs.
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