Baker Hughes Masoneilan SVI II AP Series, Быстрый старт

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= Masoneilan SVI II AP Digital Positioner Quick Start Guide | 52
Compliance Voltage in Single Drop Current Mode
The SVI II AP requires 9.0 V at 20 mA and 11.0 V at 4 mA.
Typical HART
®
devices require MORE Voltage at higher
current and MORE current source have LESS Voltage
available at higher current. The SVI II AP is noteworthy in that it
requires LESS Voltage at higher current that complements the
characteristic of the source requiring only
9 V at 20 mA
. See
“Determining an SVI Positioner Compliance Voltage in a
Control System” on page
119.
Verify Wiring and Connections
NOTE
For split range installations the compliance voltage
must be capable of the minimum span being 5 mA;
the upper range value must be 8 mA
to 20 mA; the
lower range values must be 4 mA to 14 mA.
Use the following procedure to ensure that the SVI II AP is
properly powered:
1. Connect a DC voltmeter across the input terminals.
For an input current between 4 and 20 mA the voltage
varies between
11 V and 9 V respective. See “Determining an SVI
Positioner Compliance Voltage in a Control System” on
page
119.
When voltage exceeds 11 V check that polarity is
correct.
If voltage is less than 9 V and polarity is correct, voltage
compliance of current source is inadequate.
2. Connect a milliampmeter in series with the current signal.
3. Verify that source can supply 20 mA to SVI II AP input. If 20
mA is not attainable, troubleshoot the source and set up.