User`s manual

<8. Maintenance>
8-4
IM 01C25B01-01E
8.4.2 ReplacingtheCPUBoardAssembly
This subsection describes the procedure for
replacingtheCPUassembly.(Seegure8.3)
■RemovingtheCPUAssembly
1) Remove the cover. If an integral indicator is
mounted, refer to subsection 8.4.1 and remove
the indicator.
2) Turn the zero-adjustment screw to the position
(where the screw head slot is horizontal) as
showningure8.3.
3) Disconnect the output terminal cable (cable
with brown connector at the end). When doing
this, lightly press the side of the CPU assembly
connector and pull the cable connector to
disengage.
4) Useasocketdriver(widthacrossats,5.5mm)
to loosen the two bosses.
5) Carefully pull the CPU assembly straight
forward to remove it.
6) Disconnecttheatcable(cablewithwhite
connector at the end) that connects the CPU
assembly and the capsule.
NOTE
Be careful not to apply excessive force to the
CPU assembly when removing it.
■MountingtheCPUAssembly
1) Connecttheatcable(withwhiteconnector)
between the CPU assembly and the capsule.
2) Connect the output terminal cable (with brown
connector).
NOTE
Make certain that the cables do not get pinched
between the case and the edge of the CPU
assembly.
3) Align and engage the zero-adjustment screw
pin with the groove on the bracket on the CPU
assembly. Then insert the CPU board assembly
straightontothepostintheampliercase.
4) Tighten the two bosses. If the transmitter is
equippedwithanintegralindicator,referto
subsection 8.4.1 to mount the indicator.
NOTE
Conrmthatthezero-adjustmentscrewpinis
placed properly in the groove on the bracket prior
to tightening the two bosses. If it is not, the zero-
adjustment mechanism will be damaged.
5) Replace the cover.
8.4.3 Cleaning and Replacing the Capsule
Assembly
This subsection describes the procedures for
cleaning and replacing the capsule assembly. (See
gure8.4.)
CAUTION
Cautions for Flameproof Type Transmitters
Users are prohibited by law from modifying the
constructionofaameprooftypetransmitter.If
you wish to replace the capsule assembly with
one of a different measurement range, contact
Yokogawa.
The user is permitted, however, to replace a
capsule assembly with another of the same
measurement range. When doing so, be sure to
observe the following.
• Thereplacementcapsuleassemblymust
have the same part number as the one being
replaced.
• Thesectionconnectingthetransmitterand
capsule assembly is a critical element in
preservationofameproofperformance,and
must be checked to verify that it is free of
dents, scratches, and other defects.
• Aftercompletingmaintenance,besureto
securely tighten the setscrews that fasten
the transmitter section and pressure-detector
section together.