4200 Series Transmitters
Instruction Manual
Form 5596
November 2006
23
Maintenance
WARNING
To avoid personal injury or property
damage from the sudden release of
pressure:
D
Always wear protective clothing
and eyewear when performing any
maintenance operations.
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
Table 8. Test Procedure (also refer to figure 11)
STEP
CONNECT DVM TO
DVM READS
(+) Lead
(
−
) Lead
1
V1
TP4
2.46 to 2.54 V dc (VREF)
2
V2
TP6
14.1 to 16.1 V dc (+15)
3
V3
TP6
2.46 to 2.54 V dc
(VREF2)
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.
1. Verify that the instrument is receiving power, and
verify that the receiving device(s) are operating
correctly.
2. If the transmitter is the problem, maintenance can
be performed by either sending the entire instrument
to the factory for repair, by replacing the printed
