NE
NE K06/1022 page 5
6. Mechanical Connection
The electrodes can be screwed into the tank cover via a pipe thread and sealed,
for example. The electrode length corresponds to the desired switching points,
and rod electrode lengths may be shortened. The electrode tip must be free of
insulating materials. The electrodes must be installed so that the electrode rods
or the pendant electrodes are not short-circuited with the side of the tank, or with
each other. Please ensure that the rods cannot buckle, or that the pendant
electrodes cannot become knotted.
The reference or earth electrode must be at least as long as the longest switching
electrode. If the side of the tank is adequately conductive and is not coated with
insulating material, it can be used as an earth electrode. The clearance between
the switching electrode and the side of the tank should be as small as possible,
so that the conductivity of the measuring distance does not fall below 20S/cm.
7. Electrical Connection
Attention! Make sure that the voltage values of your system
correspond with the voltage values of the measuring unit. Make sure
that the supply wires are de-energised.
Maximum cable length: 300 m, minimum cross-section 0,5 mm². A
screened, low capacity cable is to be used at a cable length of approx. 15
m and near EMC-critical installation environement. The cable needs to be
connected to an adequate shield ground.
7.1. Electrode relay NE-104
The NE-104 electrode relay is the standard relay for all
conductive limit electrodes. It is supplied as a break
relay, i.e., the relay picks up (contact 6-7 closes) when
auxiliary power is applied. If the electrodes are wetted or
the power fails, the relay disengages (contact 7-8
closes). The signal lamp (red LED) is energised when
the relay picks up.
