S+S Regeltechnik THERMASGARD HFTM Notice D'instruction page 15

G U
Measuring transducers, calibrateable, with active output
Working resistance diagram
800
700
600
500
400
300
250
200
50
10 15 20
Operating voltage (V DC)
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!
Connecting scheme
Power supply
AC 24V~ 0V
DC 15-36V = GND
TM xx - I
(2-wire-I)
4...20mA
Admissible
range
25 30 35 36 40
Individual operation
Circuitry
V
Dependency of output voltage
on output current
Ia
[ mA ]
20
15
10
5
4
0
0 1 2 3
25
Dependency of output current
on output voltage
Ua
[ V ]
10
8
6
4
2
0
0 1
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!
Connecting scheme
Power supply
AC 24V~ 0V
DC 15-36V = GND
15
4 5 6 7 8 9
450 500
2 3
Parallel operation
Circuitry Circuitry
Rev. Data-V20
TM xx - A
(AOS-I)
4...20mA
Ua
10 [ V ]
Ra
[ Ω ]
TM xx - A
(AOS-U)
0 -10 V
Ia
[ mA ]
4