Troubleshooting Procedures; Transmitter Circuit - Emerson Fisher 4200 Instruction Manual

Instruction Manual
D200354X012
D Do not remove the actuator from the valve while the valve is still pressurized.
D Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the
actuator cannot suddenly open or close the valve.
D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
on both sides of the valve.
D Use lock‐out procedures to be sure that the above measures stay in effect while you work on the equipment.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
CAUTION
When replacing components, use only components specified by the factory. Always use proper component replacement
techniques, as presented in this manual. Improper techniques or component selection may invalidate the approvals and
the product specifications, as indicated in table 1. It may also impair operations and the intended function of the device.
WARNING
On an explosion‐proof instrument, remove the electrical power before removing the instrument covers in a hazardous
area. Personal injury or property damage may result from fire and explosion if power is applied to the instrument with the
covers removed, in a hazardous area.
Test equipment for the following procedure is listed in the Calibration section. Voltage references in this procedure
may vary depending on the temperature of the instrument. The voltages below are taken at approximately 22_C
(72_F) ambient temperature.
CAUTION
Electrostatic voltages present in the environment may be transferred to the transmitter printed wiring board which may
cause failure or degraded performance. Use appropriate antistatic procedures when working with the printed wiring board
to protect the electronic circuits.
The following procedures consider the instrument assembled with all components installed according to the type
number description. The following procedures can be used in the field or for a bench check. Connect the instrument as
shown in figure 8 for bench check.

Troubleshooting Procedures

Transmitter Circuit

Note
On transmitters with position switches, the (R) terminal on the field circuit printed wiring board must be connected to the power
supply negative (-) terminal for proper transmitter operation, even though the position switch outputs are not used.
4200 Transmitters
March 2011
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