VEGA Capacitive electrodes EL 4 … 20 mA - Compact - Manual (Page 18)

18 Capacitive electrodes EL 4 … 20 mA - Compact
22652-EN-020809
Fig. 2.3 Moisture
Mounting
Fig. 2.2 Shortening the electrode
Shortening the electrode
Fully insulated electrodes have fixed dimen-
sions which must not be modified in any way.
Any modification will destroy the instrument.
Partly insulated cable or rod electrodes can
be shortened if necessary. The basic capaci-
tance of the electrodes is compensated auto-
matically at adjustment time. Because of this,
the electrodes can be shortened by any de-
sired amount.
Cable electrode EL 31 can also be shortened
(see fig. 2.2). Loosen the two pins on the
gravity weight (hexagon socket) and remove
them. Pull the cable out of the gravity weight.
To avoid fraying the steel cable (EL 31) during
cutting, you must tin the cable around the
cutting position with a soldering iron or
blowtorch, or tightly wrap the cable with a
wire. Shorten the electrode cable with a metal
cutting saw or a cutting-off wheel by the re-
quested length.
Carry out an adjustment. The instruction is
under „4.1 Adjustment“.
Filling opening
Install the electrode such that it does not pro-
trude directly into a strong filling stream.
Should such an installation location be neces-
sary, mount a suitable protective sheet in front
of the electrode, e.g. L 80 x 8 DIN 1028, etc.
Humidity from outside
To avoid moisture ingress, the connection
cables to the electrode housing of vertically
installed electrodes should be led downward
directly outside the cable entry. Rain and
condensation water can then drain off.
This is mainly valid for outdoor mounting, in
areas where high humidity is expected (e.g.
from cleaning processes) or for cooled or
heated vessels (see fig. 2.3).
Cable entries
When mounting outdoors, on cooled vessels
or in humid areas where cleaning is done, e.g.
with steam or high pressure, the seal of the
cable entry is very important.
Use cable with round cross-section conductor
and tighten the cable entry. The cable entry is
suitable for cable diameters of 5 mm to 9 mm.