Checking The Anode Earth Current With An Anode Tester; Checking The Protective Magnesium Anode; Replacing The Protective Magnesium Anode - Viessmann VITOCAL 151-A Installation And Service Instructions Manual

Checking the anode earth current with an anode tester

Fig. 62

Checking the protective magnesium anode

We recommend replacing the protective magnesium
anode once it has been reduced to a diameter of 10 to
15 mm.

Replacing the protective magnesium anode

Note
If the protective magnesium anode needs to be
replaced, a maintenance-free impressed current anode
(accessories) can be used.
For removal of the protective magnesium anode: See
diagram in chapter "Draining the appliance on the
DHW side".
C B A
Commissioning, inspection, maintenance
1. Remove thermal insulation
2. Remove earth cable
B
sium anode .
A
3. Connect the tester (measuring range up to 5 mA)
in series across tab
A
anode and earth cable
Anode earth Protective magnesium anode
current
> 0.3 mA Function OK
< 0.3 mA Visual inspection required: See
chapter "Testing the protective
magnesium anode".
4. Insert thermal insulation
!
Please note
A short circuit between the protective magne-
sium anode and the indirect coil negates the
protective effect of the magnesium anode. This
leads to corrosion damage on the DHW cylinder.
Before connecting the electrical cables, check
the resistance across terminals
diagram in chapter "Cleaning the DHW cylin-
der"). If the resistance is significantly less than
infinity, check whether the protective magnesium
anode is touching the indirect coil.
C .
from protective magne-
of protective magnesium
.
B
.
C
and (see
A B
81