Instructions for Use SS 20.200
Page 6
4 Electrical connection
For proper operation the sensor requires a DC power supply with a nom-
inal value of 24 V with permitted tolerance of 20 %. Typical current con-
sumption is approx. 40 mA and at maximum 70 mA (without load of the
switching output), depending on the flow velocity.
Only operate sensor in the defined range of operating voltage
(24 V
DC
± 20 %).
Undervoltage may result in malfunction; overvoltage may lead
to irreversible damages.
The specifications for the operating voltage are valid for the internal con-
nection of the sensor. Voltage drops generated due to cable resistances
must be considered by the customer.
Connecting cable assignment
The sensor is equipped with a cable firmly fixed to its housing with 2 m
length and open cable ends (pin assignments see following graphic).
Sensor
+24V
R1
R
ON
R2
Gnd
WH (white)
YE (yellow)
GN (green)
Z
During electrical installation ensure that no voltage is applied
and inadvertent activation is not possible.
For signalling, a semiconductor relay is used. Its galvanically decoupled
switching output has a maximum permanent switching power of 300 mW
(R
on
with typically 20
, up to max. 25
). The switching current should
be at most 100 mA, the peak value of the switching voltage (AC or DC)
must not exceed 30 V. Otherwise the bidirectional protecting diode (Z)
between the load circuit terminals will break down and can be thermally
destroyed (see connecting diagram).
The specified electrical operating values must not be exceeded.
Exceeding them may lead to irreversible damage.
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