Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 16)

<2. Instruction for Replacement of the Heater Unit>
2-7
IM 11M12A01-21E
2.2.1 Replacement of the Heater Unit
1. Removing of the Sensor (Cell)
Remove the U-shaped pipe support, the U-shaped pipe, the Filter and the Sensor (Cell) according to
chapter 2.11 ”Removal procedures of the sensor assembly”.
2. Removing of the Converter Case
(1) Remove the two screws
⑮ that fasten the cover ⑫ and slide it to the flange side.
(2) Remove the four bolts ⑩ and the converter ⑯. Then remove the three connectors to which lead-
wire from the heater, CELL+ signal and thermocouple are connected.
If the automatic calibration unit is attached, the wires from solenoid valves are connected to the
converter with connectors.
3. Replacement of Heater Strut Assembly
(1) Loosen screw
⑲ until heater strut assembly’s plate ⑰ can be removed. There’s no need to
remove O-ring ⑱ which prevents screw ⑲ from coming out. Pull out connector ⑬.
(2) Loosen and remove the screw ⑧ with a special tool (part no. K9470BX or equivalent) and then
remove the heater strut assembly ㉓ from the detector ㉔.
(3) To reassemble the heater strut assembly, reverse the above procedure:
Insert the heater strut assembly ㉔ into the detector ㉔, while inserting the calibration pipe in
the detector ㉔ into the heater section in the heater strut assembly ㉓ as well as in the bracket
hole. Coat the screw ⑧ with grease (NEVER SEEZ: G7067ZA) and tighten the screw ⑧ with a
special tool (part no. K9470BX or equivalent) with a tightening torque of 12N•m10%. (screw ⑧
attached with heater strut assembly ㉓ is shipped with coating.)
4. Assembling of Connector
(1) To install the O-rings
㉒ on the calibration gas and reference gas pipes, disassemble the
connector ⑬ in the following procedure.
Remove the screw ㉕ and then remove the plate ⑰ and two caps ⑳. If the O-ring ㉒ remains in
the hole, pull them out from the back.
(2) Pass the heater, CELL+ and thermocouple lead-wire through the connector ⑬. Also, pass the
calibration gas and reference gas pipes through the holes of the connector ⑬.
(3) Insert the calibration gas and reference gas pipes into O-rings ㉒ after confirming no damage of
O-rings. If the O-ring ㉒ fails, replace it with a new one.
(4) Push the two caps ⑳ into the associated opening of the connector ⑬. Insert the plate ⑰,
aligning it with the groove of the cap ⑳, and tighten it with the screw ㉕. At this time, fix the
terminal of the end of green wire from the four core connectors to connector ⑬ by screw ㉕. If
you attempt to insert the calibration gas and reference gas pipes into the connector ⑬ without
disassembling the connector ⑬, the O-ring may be damaged.
(5) Tighten the screw ⑲ in heater strut assembly ㉓ until connector ⑬ cannot move.
5. Assembling of Converter and Wiring
Reassemble in reverse order to the above disassembly procedure.
Each connector from the heater strut assembly is identified by its size and the number of cores. Insert
them fully by taking care of their size and direction. The connectors from solenoid valves are marked
“ZERO” or “Z” and “SPAN” or “S”, so correspond each marking with converter’s.
6. Installing of the Sensor (Cell)
Install the U-shaped pipe support, the U-shaped pipe, the Filter and the Sensor (Cell) according to
section 2.1.3 ”Part assembly of the sensor assembly”. heater strut assembly ㉓ is shipped with a new
contact.