Yokogawa EJA110E - Manual (Page 42)

<8. Maintenance>
8-3
IM 01C25B01-01E
8.4 Disassembly and
Reassembly
This section describes procedures for disassembly
and reassembly for maintenance and component
replacement.
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 Quantity Remarks
Phillips
screwdriver
1 JIS B4633, No. 2
Slotted
screwdriver
1
Allen wrenches 3 JIS B4648
One each, nominal 3, 4 and
2.5 mm Allen wrenches
Wrench 1 Width across flats, 17 mm
Torque wrench 1
Adjustable
wrench
1
Socket wrench 1 Width across flats, 16 mm
Socket driver 1 Width across flats, 5.5 mm
Tweezers 1
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
reassembled 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
shrouding bolt to a torque of 0.7 N·m.
Shrouding Bolt
Shrouding Bolt
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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.
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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