IM 01C25F01-01E
8-3
8. MAINTENANCE
8.4 Disassembly and Reassem-
bly
This section describes procedures for disassembly and
reassembly for maintenance and component replace-
ment.
Always turn OFF power and shut off and release
pressures before disassembly. Use proper tools for all
operations. Table 8.2 shows the tools required.
Table 8.2 Tools for Disassembly and Reassembly
Tool
Remarks
Quantity
Phillips screwdriver
Slotted screwdriver
Allen wrenches
JIS B4648
One each, nominal 3, 4 and
2.5 mm Allen wrenches
Wrench
Torque wrench
Adjustable wrench
Socket wrench
Socket driver
Tweezers
1
1
3
1
1
1
1
1
1
JIS B4633, No. 2
Width across flats, 17 mm
Width across flats, 16 mm
Width across flats, 5.5 mm
T0802.EPS
CAUTION
Precautions for ATEX Flameproof Type
Transmitters
• Flameproof type transmitters must be, as a
rule, removed to a non-hazardous area for
maintenance and be disassembled and reas-
sembled to the original state.
• On the flameproof type transmitters the two
covers are locked, each by an Allen head bolt
(shrouding bolt). When a shrouding bolt is
driven clockwise by an Allen wrench, it is going
in and cover lock is released, and then the
cover can be opened.
When a cover is closed it should be locked by a
shrouding bolt without fail. Tighten the shroud-
ing bolt to a torque of 0.7 N·m.
Shrouding Bolt
Shrouding Bolt
F0802.EPS
Figure 8.2 Shrouding Bolts
8.4.1 Replacing the Integral Indicator
CAUTION
Cautions for Flameproof Type Transmitters
Users are prohibited by law from modifying the
construction of a flameproof type transmitter.
This would invalidate the agency approval for
the use of the transmitter in a rated area.
It follows that the user is prohibited from using a
flameproof type transmitter with its integral
indicator removed, or from adding an integral
indicator to a transmitter. If such modification is
absolutely required, contact Yokogawa.
This subsection describes the procedure for replacing
an integral indicator. (See figure 8.3)
Removing the Integral Indicator
1) Remove the cover.
2) While supporting the integral indicator with one
hand, loosen its two mounting screws.
3) Dismount the LCD board assembly from the CPU
assembly.
When doing this, carefully pull the LCD board
assembly straight forward so as not to damage the
connector pins between it and the CPU assembly.
Attaching the Integral Indicator
1) Align both the LCD board assembly and CPU
assembly connectors and engage them.
2) Insert and tighten the two mounting screws.
3) Replace the cover.
F0803.EPS
Press
forward
Output terminal cable
Zero-adjustment
screw pin
Slide
switch
Boss
Zero-
adjustment
screw
Integral
indicator
Mounting screw
Amplifier Cover
CPU assembly
Bracket
(for zero-adjustment
screw pin)
LCD board assembly
Figure 8.3 Removing and Attaching LCD Board Assembly
and CPU Assembly