Servomex 01440002D, Service Manual

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01440D Light Industrial Gas Analyser Service Manual. 2.3
2.3 Servicing the Oxygen Transducer
2.3.1 Replacement of the 1158 Transducer
1. Carefully remove the foam cover from the transducer and disconnect
the 16-way ribbon cable from the transducer, the sample connections
to the cell and the heater and thermal fuse wires from TB2 on front
the panel PCB.
2. Loosen the 4 off M4 nuts retaining the bracket that the transducer is
located on. Slide the whole assembly to one side and lift out from the
analyser.
With 01440D1FTX versions, when the assembly is free, unsolder the
Yellow and Black wires from the transducer cell connections. Move
the sleeves on the Pink and Grey wires and unsolder them from the
yellow and black wires from the transducer PCB.
3. Unscrew the transducer from the bracket by the 3 off screws located
on the underside of the bracket, then remove the remaining insulation
and the 3 off M4 pillars.
4. Remove the thermal fuse and heating element, from the underside of
the transducer, being careful not to damage it.
5. Installation is the reverse of the removal process. Ensure thermal
fuse and heater are correctly reconnected. For wiring see Figure 2.7
(or 2.10 for FTX version).
With 01440D1FTX versions, the Yellow and Black wires to the cell on
the new transducer must be unsoldered and then resoldered to the
Pink and Grey wires from the Protection PCB (connect Yellow to Pink
and Black to Grey). Replace the sleeves and fit a cable tie to secure
them.
The Yellow and Black wires from the Protection PCB must be
soldered to the transducer cell connections (Yellow to the connection
marked with yellow spot).
WARNING
• The opening of covers or removal of parts, except those to which
access can be gained by hand, may expose electrical terminals.
Ensure power is disconnected before working on the analyser.
NOTE
• Due to the strong magnetic field, which exists around the transducer, it
is advisable to remove wristwatches if worn when servicing the oxygen
transducer.