YOKOGAWA PH450G

<4. Operation>
4-9
IM 12B07W01-04EN 1st Edition : Nov. 11, 2016-00
The manufacturer recommends that, in the early stages of operation, you choose from the
following parameters that can be changed and then change them at regular intervals to verify the
cleaning effect so you can nd the optimum conditions for cleaning.
• Concentration of chemical solution (No data is required to change.)
• Interval between WASHs
• WASH time
• Bubbling time
4.4.2 Inspections During Regular Operation
Routine inspection must be made according to the items shown in Table 4.2 to ensure that
the chemical cleaning system is free from faults during regular operation. For inspection and
maintenance implemented during a system shutdown to maintain system performance, see
Chapter 5. For details on the items of inspection for the FLXA202/FLXA21, PH450G pH/ORP
converter or PH8EFP pH sensor, refer to those corresponding manuals.
Table 4.2 Inspection During Regular Operation
Inspection Item
Acceptance Criterion
(Corrective Action When Criterion Is Not Met)
Recommended
Frequency of
Inspection
Amount of chemical solution
remaining in holding tank
The tank must holds not less than the required amount (the
level indicated on the tank). (Rell the tank if the liquid is below
the specied level.)
Approximately once a
month
(100 ml per rell)
Amount of contaminants
on the cylinder of PHSHS3
holder
The cylinder must be free of contaminants that would prevent it
sliding properly. In addition, any applied lubricating grease must
provide good 1ttbrication (the cylinder starts moving smoothly).
Approximately once a
month
Pneumatic pressure setting
of pressure reduction valves
in control box
The PG1 and PG2 pressure gauges en the AS1 and AS2
pressure reduction valves must indicate their preset readings,
respectively. (If they fail to indicate the preset readings, adjust
them.)
Approximately once a
month
Amount of contaminants on
the wetted part of sensor
holder
The wetted part must be free of any contaminants that could
get into the cleaning chamber while the sensor holder was
rising or descending.
Approximately once a
month
If your system requires immediate corrective actions as a result of inspection, perform the
necessary maintenance work while observing safety precautions.
WARNING
There is a possibility of personal injury or equipment damage during maintenance of the holder.
Exercise utmost care to ensure that no cleaning takes place during maintenance work.
4.4.3 Behaviour During Power Failure/Restart
The sensor holder moves to its lowest position and stays there, whether the system is in the
measurement mode or the WASH mode, if a power interruption lasts longer than the allowable
time for a momentary power failure in which the system is able to maintain normal operation. The
system resets to the measurement mode when restarted. It goes into the WASH mode, however,
if the MANUAL WASH switch in the control box is left turned on.
4.4.4 Operation When Shutting Down the System
It is fundamental to system operation that the pH sensor be maintained in excellent working
condition and that the system be able to resume normal pH measurement when it is restarted.
Follow the instructions given here before cutting off the power supply.