2
DEVICE DESCRIPTION
10
SITRANS FX300
www.siemens.com/flow 05/2015 - SFIDK.PS.050.G1.02 A5E02172013
2.8 Electrical data
Signal circuits
Signal circuitsSignal circuits
Signal circuits
The vortex flowmeter signal circuits may only be connected to separate, intrinsically safe
circuits. The maximum permissible values considered safe are listed below. The connection may
only be made using separately certified intrinsically safe isolating amplifiers or zener barriers
with the following maximum values per circuit:
• U
i
=30V
• I
i
= 100 mA
• P
i
=1,0W
The following values are to be observed for each intrinsically safe circuit in case of
interconnection:
• C
i
=15nF
• L
i
≈ 600 µH
Sensor circuits
Sensor circuitsSensor circuits
Sensor circuits
With the compact device, the intrinsically safe sensor circuits are designed as internal circuits.
When it comes to the remote versions, the intrinsically safe sensor circuits are led through. The
maximum permissible values of the sensor circuits considered safe are listed below:
Piezo / Pt1000 circuit
• U
o
=30V
• I
o
=62mA
• P
o
= 340 mW
• C
o
=22nF
• L
o
= 0,35 mH
Pressure transmitter circuit
• U
o
=30V
• I
o
= 100 mA
• P
o
= 509 mW
• C
o
=44nF
• L
o
=0,4 mH