Model 640 & 640CC Instruction Manual
D01206676
Revision A February 2016
38
Use care when working near the heater terminals. They are
easily bent or broken.
2.
With a spanner wrench, loosen lock ring is found in the recessed hole in the
bottom of the pressure vessel.
3.
Push the magnetic drive housing up through the pressure vessel bore and out
the top. It may be necessary to gently tap the housing with a hammer to break
it loose if it is cemented in place. If cement contamination is severe, cement
may have to be removed out through the bore of the pressure vessel before the
housing can be removed.
4.
Replace the Teflon o-ring prior to assembly.
5.
Assembly is the opposite of disassembly.
Heater Replacement
12.12
Heater should be replaced if a hole burns through the sheath or if the heater fails to
heat. The replacement steps are listed below.
Make certain that the power to the instrument is disconnected
before servicing the heater. Severe shock or electrocution could
occur if contact is made with a live heater circuit.
1.
Remove the upper heater spreader from the pressure vessel bore.
2.
Remove the contact pin shield.
3.
Remove wires from the contact pins and the ground pin and note to which pin
each wire is connected.
4.
Remove the lower heater spreader.
5.
Remove the magnetic drive rotator assembly as described above.
6.
Remove wires from heater terminals.
7.
Remove both heater nuts.
8.
Tap on heater ferrules until loosened then pull heater out through bore of
pressure vessel.
