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6.0 MAINTENANCE
The WDB controller itself requires very little maintenance. Wipe with a damp cloth. Do not spray down
the controller unless the enclosure door is closed and latched.
6.1 Electrode
Cleaning
NOTE: The controller must be recalibrated after cleaning the electrodes.
Frequency
The electrodes should be cleaned periodically. The frequency required will vary by installation. In a new
installation, it is recommended that the electrodes be cleaned after two weeks of service. To determine
how often the electrodes must be cleaned, follow the procedure below.
1. Read and record the conductivity.
2. Remove, clean and replace the conductivity electrodes in the process.
3. Read conductivity and compare with the reading in step 1 above.
If the variance in readings is greater than 5%, increase the frequency of electrodes cleaning. If there is less
than 5% change in the reading, the electrodes were not dirty and can be cleaned less often.
Cleaning Procedure
The electrodes can normally be cleaned using a cloth, toothbrush, cotton swab or paper towel and a mild
cleaning solution such as 409
®
cleanser. Occasionally electrodes may become coated with various
substances which require a more vigorous cleaning procedure, such as immersion in dilute muriatic acid.
Usually the coating will be visible, but not always. If normal cleaning does not improve the performance,
try a 1% muriatic (hydrochloric) acid rinse.
6.2
Replacing the Fuses
CAUTION
: Disconnect power to the controller before opening front panel!
Locate the fuses on the circuit board at the back of the controller enclosure. (See figure 3) Gently remove
the old fuse from its retaining clip and discard. Press the new fuse into the clip, secure the front panel of
the controller and return power to the unit.
Warning:
Use of non-approved fuses can affect product safety approvals. Fuse ratings depend on
controller power rating. Specifications are shown below. To insure product safety certifications are
maintained, it is recommended that a Walchem fuse is used.
F1 Fuse
Walchem P/N
F2 Fuse
Walchem P/N
5 x 20 mm, 1.0A, 250V
103163
5 x 20 mm, 6A, 250V
102864
