Spirax Sarco SP400 - Single loop applications; Multi-loop applications

IM-P343-37 CTLS Issue 4
22
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TRANSLATION RUN OVER
SP400 Electropneumatic Smart Positioner
Fig. 27
4 - 20 mA signal
3 4
+ -
6.2.2 Single loop applications
The SP400 is loop powered using the 4 - 20 mA input signal source providing a minimum signal of 3.6 mA
can be maintained.
Minimum current 3.6 mA
Maximum current 30 mA
Maximum voltage drop < 7 V
Overvoltage protection Up to 30 Vdc
Protection against polarity inversion Up to 30 Vdc
6.2.3 Multi-loop applications Loop powered multi-positioner connections
Fig. 28
In a loop powered application, the 4-20 mA signal must be capable of supplying a minimum of 7 V per
positioner at 20 mA. In a split range application the signal source must be capable of supplying sufficient
voltage, i.e. 14 V is enough to power 2 positioners.
3 4
Positioner 1
3 4
Positioner 2
+
4 - 20 mA signal @ 14 V minimum
-