S+S Regeltechnik HYGRASGARD RFF Series, Operating Instructions, Mounting & Installation

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15
Load resistance diagram
4 … 20 mA
G
HYGRASGARD ® RFF ⁄ RFTF
NOTE
For 4 ... 20 mA devices, DC voltage must be used (without residual
ripple, see permissible range of load resistance diagram). Do not use
pulsating DC voltage.
800
700
600
500
400
300
250
50
200
10 15 20 25 30 35 36 40
Load resistance diagram
W
orking r
esis
tanc
e (Ohm)
Operating voltage (V DC)
Admissible
range
Connecting scheme Parallel operation
Connecting scheme Individual operation
Circuitry Circuitry
0...10V 0V/GND 0...10V 0V/GND
Power supply
AC 24V~ 0V
DC 15-36V = GND
Circuitry
0...10V 0V/GND
V
Power supply
AC 24V~ 0V
DC 15-36V = GND
SUPPLY VOLTAGE :
For operating voltage reverse polarity protection, a one-way rectifier or
reverse polarity protection diode is integrated in this device variant.
This internal one-way rectifier also allows operating 0 - 10 V devices on AC
supply voltage.
The output signal is to be tapped by a measuring instrument. Output
voltage is measured her against zero potential (O V) of the input voltage!
When this device is operated on DC supply voltage , the operating voltage
input UB+ is to be used for 15...36 V DC supply and UB – or GND for
ground wire!
When several devices are supplied by one 24 V AC voltage supply , it is to
be ensured that all ”positive“ operating voltage input terminals (+) of the
field devices are connected with each other and all ”negative“ operating
voltage input terminals (–) (= reference potential) are connected together
(in-phase connection of field devices). All outputs of field devices must be
referenced to the same potential!
In case of reversed polarity at one field device, a supply voltage short-
circuit would be caused by that device. The consequential short-circuit
current flowing through this field device may cause damage to it.
Therefore, pay attention to correct wiring!