Dresser Masoneilan SVI II AP-2, Быстрый старт

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Masoneilan Dresser SVI II AP Quick Start Guide
10
Wiring the
SVI II AP
In order for the SVI II AP to communicate the positioner data the SVI II
AP must be physically connected to a HART communication. The
procedure below outlines wiring the SVI II AP.
™ Comply with current national and local regulations
for electrical installation work.
™ Comply with national and local explosive
atmosphere regulations.
™ Before carrying out any work on the device, power
off the instrument or make sure that the locale
conditions for potentially explosive atmosphere
permit the safe opening of the cover.
Connecting to the Control Loop
The SVI II APpositioner MUST BE grounded according to local
regulations. It is important to maintain correct polarity at all times,
otherwise the positioner may not operate properly. The SVI II AP
should be physically connected to the HART loop using a cable
specified by the HART Communication Foundation. A shielded cable
is recommended.
To connect the Control Loop to the SVI II AP:
1. Connect one end of the cable to the control loop's
4 - 20mA output
2. Remove the threaded wiring covers on the positioner.
3. Connect the other end of the cable to the SVI II AP. There
are two threaded openings on the positioner. Use the
opening with the red plastic insert.
4. Maintain po and - respectively.
Wiring Guidelines
This list contains eight guidelines for a successful implementation of DC
current signal, DC power, and HART communication to the SVI II AP:
1. Compliance voltage at the SVI II AP must be 9 volts at the
maximum current of 20 mA.
2. Signal to the SVI II AP must be a regulated current in the
range 3.2 to 22 mA.
3. Controller output circuit must be unaffected by the HART
tones which are in the frequency range between 1200 and
2200 Hz.
4. Frequency range of the HART tones must have a circuit
impedance of more than 220 Ohms, typically 250 Ohms.
5. HART tones may be imposed by the positioner and a
communication device located anywhere on the signaling
circuit.