Evoqua WALLACE & TIERNAN MFC, Instruction Manual

Page: 207 / 268

MFC
Maintenance
7.
207
Replacing electrolyte,
electrodes and diaphragms
1 Remove DEPOLOX
®
5 flow block assembly cover.
2 Close the ball valve on the sample water inlet and on the outlet
(pressurised version).
3 Open the drain valve and drain the cell body (hold container
underneath).
4 Close the drain valve when the cell body is empty.
5 Remove the sensors. Loosen the cable union (hold the cable
while doing this as it may not be allowed to rotate).
6 Loosen the lower cap on the 3 electrode cell.
7 Remove the signal cable.
Replace electrolyte 8 Unscrew the upper knurled nut on the electrolyte container.
9 Remove the electrolyte tank out of the cell body from below
using the electrode mount.
Please note
Wash the cell sand out of the electrode mount “Replacing cell sand
in DEPOLOX® 5 three-electrode cell" on page 205 “.
10 Remove the electrolyte container from the electrode mount.
To do this, unscrew the knurled nut in the electrode mount.
11 Remove the electrolyte container out the electrode mount from
the top.
12 Remove the drain plug from the electrolyte container.
13 Turn the electrolyte container upside down and drainthe KCI
electrolytes by lightly shaking it.
Replacing reference electrode 14 If necessary, replace the reference electrode.
The reference electrode can be unscrewed from the
electrolyte container. Lightly wet the O-ring before installinga
new reference electrode.
Replacing diaphragms
Please note
The diaphragms, which form the contact between the reference
electrodes and sample water, cannot be cleaned. If the water
quality is very good, the diaphragms can remain installed for up to
three years; they should be replaced thereafter (no exceptions). If
the sample water quality is poor, the diaphragms may be soiled.
This influences the measuring accuracy.
15 Remove both diaphragms from the electrolyte container using
a suitable tool (e.g. tweezers).
16 Push new diaphragms into the electrolyte container. Lightly
wet the O-rings.
17 Insert the electrolyte container back into the electrode mount.
Lightly wet the O-ring here as well.