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Manual for installation of the Sensformer® Connectivity Device
(2) This device must accept any interference, including
interference that may cause undesired operation of the device
French: Le présent appareil est conforme aux CNR d'ISDE Canada
applicables aux appareils radio exempts de licence. L'exploitation
est autorisée aux deux conditions suivantes : (1) l'appareil ne doit
pas produire de brouillage, et (2) l'appareil doit accepter tout
brouillage radioélectrique subi, même si le brouillage est
susceptible d'en compromettre le fonctionnement.
5.2.2. Analog inputs
The purpose of the analog input channels is to condition the
incoming analog signals for measuring and digitalization, as well
as providing electrical protection to the other system component
behind. The analog input channels can also provide 24 VDC power
supply to the connected sensors, widening the range of possible
sensors.
The main parameters of the input channels are the following:
Number of
analog inputs
Analog inputs type
Terminal type
Separation class
Terminal isolation
Polarity
Input impedance
Supply voltage
Maximum supply current 120 mA (sum of all ports)
Size of conductor
Table 12 - Parameters of analog inputs
3
4-20mA DC (active or passive)
or ±20mApp AC (passive)
3-pole
Class III (SELV)
AC 3 kV
Independent
in
±20mA
Polarity sensitive in 4-20 mA mode.
120
Ohm (4-20mA
mode)
80 Ohm (±20 mA mode)
24 VDC
2
1.5 mm
© 2020 Siemens Energy
Analog input in 4-20mA mode
Figure 28 - Schematic of 4-20mA analog input
Example of a 4-20mA CT configuration:
Let's assume using a 100A/4...20mA current transducer. This
means the output of the transducer is 4mA in case of 0A primary
current and 20mA in case 100A primary current. The output in-
between is linear to the current change on the primary side. In
this case the measured values are:
4 * x + y = 0 and 20 * x + y = 100, where the x is the gain and y is
the offset of the conversion. Solving the equations, the
parameters of the channels are: x = 6.25 and y = -25 (so: the gain
mode,
is 6.25, offset is -25).
These parameters shall be set in the input channel configuration
or
on the settings page of web GUI.
Analog input in ±20mA mode
Figure 29 - Schematic of ±20mA analog input
Example of a ±20mA CT configuration
For driving the input of Sensformer Connectivity Device in ±20mA
mode, use a CT that is capable of driving 40 Ohm load. Make sure
the CT doesn`t overload the input.
For example, using a 1020 current transformer with maximum
input current 20A and turn ratio 1000:1, when the Sensformer
Connectivity Device measures 20mA RMS current, the primer
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