< 8. Maintenance >
8-9
IM 12F5A1-01E
8.2.4 Check/Maintenance/ReplacementofMotorandGear
Head
[ProcedureforCheckingandMaintenance]
At zero calibration time, operate the indicator electrode and check the following. ( once in three
months recommended)
• Check there’s no irregularity in rotation speed of drive shaft. If there’s any irregularity, loose
theloadontheshaftbylooseningthescrewswhichxthedrivenshaftpulley,andrecheck.
If there is still irregularity, replace motor and gear head. If the irregularity doesn’t reappear,
check the driven shaft assembly.
• Abnormal sound from gear head (motor).
If there’s any abnormal sound, check the motor / gear head. (In principle, this should be
done by Yokogawa).
Also,approximatelyonceinsixmonths,checkthefollowingitemsaswell:
• Motor rated torque and drive torque.
In <CELL> mode, when motor is turned ON/OFF, after the ON command it should quickly
reachspeed.Conrmthatthedierenceinspeedofrotationbetweenitsnormalstatus,and
whenloadisreducedbylooseningscrewsxingpulleytodrivenshaft,isnotnoticeable.
If operation is still not satisfactory, replace motor and gear head.
[Replacementprocedure]
Replacement of motor and gear head should, in principle, be carried out by Yokogawa service.
If you want to do it yourself, the procedure is as follows:
• In principle, replace motor and gear head at the same time as periodic replacement of other
parts. Replace complete motor assembly consisting of both motor and capacitor.
• Whenreplacingmotorassemblyandgearhead,rstremovemotormountingplatefrom
base.
There are no special cautions relating to removal of, or reassembly of, motor assembly and
gear head.
However,thepartssuchaselectrode, rotating contact and drive belt, which are removed to
detach motor assembly mounting plate, should be carefully reassembled, referring to Sec.
8.2.1throughSec.8.2.3.
• The terminal board in motor assembly should be set same position of “C1” and “C2 ” printed
on the plate, whose wire color of “C1” is yellow/green and “C2” is pink/black.