Instruction Manual
D103292X012
C1 Controllers and Transmitters
March 2017
30
Maintenance
If the installation includes a Fisher 67 filter regulator, periodically open the drain on the filter regulator to drain
accumulated moisture. Also, push the spring-out cleaning wire on the relay orifice. Check the opening of the vent
assembly (key 28, figure 2) or the opening of the remote vent pipe, if one is used. If necessary, clean the openings.
Parts are subject to normal wear and must be inspected and replaced as necessary. The frequency of inspection and
parts replacement depends upon the severity of the service conditions.
WARNING
The following maintenance procedures require taking the controller out of service. To avoid personal injury and property
damage caused by the release of pressure or process fluid, observe the following before starting maintenance:
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Always wear protective clothing, gloves, and eyewear.
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Provide some temporary means of control for the process before taking the controller out of service.
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Provide a means of containing the process fluid before removing any measurement devices from the process.
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Use lock-out procedures to be sure that the above measures stay in effect while you work on the equipment.
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Personal injury or property damage may result from fire or explosion if natural gas is used as the supply medium and
appropriate preventative measures are not taken. Preventative measures may include, but are not limited to, one or
more of the following; Remote venting of the unit, re-evaluating the hazardous area classification, ensuring adequate
ventilation, and the removal of any ignition sources. For information on remote venting of this controller/ transmitter,
refer to page 11.
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Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
Replacing Gauges
Refer to figures 22 and 23 for key number locations unless otherwise directed.
Three gauge configurations are available for C1 units.
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Output and supply pressure indications
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Output and process pressure indications
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Output, process, and supply pressure indications
One gauge type (key 2) is used for both output and supply pressure indications when the gauges are installed inside
the controller case. Key 2 features a 1/8-inch connecting stem that matches the threaded gauge boss extending from
the relay base.
In some cases, a process pressure gauge (key 4) covers the position of the internal supply pressure gauge. The supply
pressure gauge has been removed and replaced with a pipe plug (key 15). The pressure control block (key 10) is
different to accommodate a different control tubing assembly (key 23) with a pressure connection (key 14) for a
process pressure gauge. If a supply pressure gauge is required, a gauge with a 1/4-inch connecting stem (key 3) must
be mounted on the supply pressure regulator.
CAUTION
Before performing this procedure, be sure the replacement gauges are the correct range so they are not damaged by
overpressure.
