YOKOGAWA FC400G

< 8. Maintenance >
8-9
IM 12F5A1-01E
8.2.4 Check/Maintenance/ReplacementofMotorandGear
Head
[ProcedureforCheckingandMaintenance]
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
theloadontheshaftbylooseningthescrewswhichxthedrivenshaftpulley,andrecheck.
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,approximatelyonceinsixmonths,checkthefollowingitemsaswell:
• Motor rated torque and drive torque.
In <CELL> mode, when motor is turned ON/OFF, after the ON command it should quickly
reachspeed.Conrmthatthedi󰀨erenceinspeedofrotationbetweenitsnormalstatus,and
whenloadisreducedbylooseningscrewsxingpulleytodrivenshaft,isnotnoticeable. 
If operation is still not satisfactory, replace motor and gear head.
[Replacementprocedure]
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.
• Whenreplacingmotorassemblyandgearhead,rstremovemotormountingplatefrom
base.
There are no special cautions relating to removal of, or reassembly of, motor assembly and
gear head.
However,thepartssuchaselectrode, rotating contact and drive belt, which are removed to
detach motor assembly mounting plate, should be carefully reassembled, referring to Sec.
8.2.1throughSec.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.