Emerson Fisher 4320 Instrukcja Obsługi Pobierz pdf (Strona 2)

Instruction Manual

D103621X012

4320 Position Monitor

April 2014

Contents (continued)

Parts 67.......................................

Repair Kits 67.................................

Replaceable Parts 67...........................

Introduction

Scope of Manual

This instruction manual includes specifications, installation, basic setup and configuration, and maintenance and

troubleshooting information for the Fisher 4320 wireless position monitor.

This manual describes using the local interface to setup and calibrate the instrument.

Do not install, operate, or maintain a 4320 wireless position monitor without being fully trained and qualified in valve,

actuator, and accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is

important to carefully read, understand, and follow all of the contents of this manual, including all safety cautions and

warnings. If you have any questions about these instructions, contact your Emerson Process Management sales office

before proceeding.

Description

Valve position is sensed through the noncontact, linkageless feedback sensor. There are no moving linkages and the

4320 is physically separated from the valve stem through the use of a magnetic Hall effect sensor. A magnetic array is

mounted to the valve stem and the sensor is embedded in the 4320 housing. The sensor is electrically connected to

the printed wiring board to provide a travel feedback signal used in the control algorithm.

On/Off Control Option

The 4320 position monitor with on/off control option relays a digital set point generated by a control host to deliver a

discrete (open/closed) control action to a valve actuator. Valve position feedback provides confirmation of the control

action, as shown in figure 2. The valve command is converted to a pneumatic output signal. The pneumatic output is

connected to the supply pressure, and depending on set point, will either open or close the valve. The output can be

used with either airtoopen or airtoclose and supports both single and doubleacting actuators. When a

single-acting actuator is used it is necessary to plug one of the output ports on the spool valve.

The on/off control device can also be configured as a snapacting controller. In this configuration, there is no feedback

signal for the controlled equipment. The state of the monitored process triggers a command to the controlled valve.

The control system is alerted to changes in the process and the valve command, but the control action remains in the

field instrument. The 4320 uses the position signal, switch thresholds, and snap-control mode setting to decide when

to open or close the valve. For example, in figure 3, when a high level in the storage tank is reached, the 4320 closes

the inlet valve. In directacting snap, high or open trip on the input causes the controlled valve to open, and low/closed

trip on the input causes the controlled valve to close. In reverseacting snap, high/open trip causes the controlled valve

to close, and low/closed trip causes the controlled valve to open.

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Emerson Fisher 4320 Instrukcja Obsługi Strona 2