VEGA VEGACAP 82-98 - Manual (Page 18)

18 VEGACAP
Moisture
When mounting outside, on cooled vessels or
in humid areas where the cleaning is done,
e.g. with steam or high pressure, the sealing
of the cable entry is very important. Use
cable with sufficient conductor cross-section
and tighten the cable entry very securely. For
cables with insufficient conductor cross-
section, an appropriate reduction insert must
be used to ensure tightness.
Two different seal rings are attached to the
instrument to also enable reliable sealing of
cables with smaller diameter in the cable
entry. Use the smallest possible seal ring.
Turn the cable entries of the instrument down-
wards to avoid moisture ingress. For this
purpose the housing can be rotated by
approx. 330°. For vertically installed elec-
trodes loop the connection line to the instru-
ment housing downwards so that rain and
condensation water can drain off (see fig.
2.5).
Extracting forces
In case of strong extracting forces e.g. due
to material inflow, high tensile loads can be
caused.
In this case use for short meas. distances a
rod electrode, as generally a rod is more
stable. If due to the length or the installation
position a cable electrode should be neces-
sary, the electrode should not be fixed but
just provided with a gravity weight, as the
cable can more easily follow the product
movements. Make sure that the electrode
cable does not touch the vessel wall.
Fasten the gravity weight of VEGACAP 35
with a plastic cable.
Pressure
In case of excess or low pressure in the
vessel, the mounting boss must be sealed on
the housing. Use the attached seal ring.
Check whether the seal ring is resistant
against the medium.
Isolating measures such as e.g., the cover-
ing of the thread with Teflon tape, can inter-
rupt the necessary electrical connection in
metal vessels. In such case earth the elec-
trode with an additional cable connection to
the vessel.
Aluminium vessel
In case of Aluminium vessels, an electrode
with steel thread should be used. The combi-
nation Aluminium on Aluminium should be
avoided, as the thread "seizes“ and cannot
be removed after some time without damage.
Mounting
Horizontal mounting
The electrode can be mounted horizontally to
achieve an exact switching point for level
detection. We recommend mounting the
electrode approx. 20° inclined to the bottom
so that build-up is avoided (see fig. 2.4).
Fig. 2.4
20˚
1 0
a. b.
Sheet