
NV
NV K13/1023 Page 5
5. Operating Principle
The Kobold Level Switch model NV is a reasonably-priced compact instrument
for monitoring levels. A stainless steel cylindrical float attached to one end of a
balance arm moves up and down with the liquid level.
The motion of the float is transferred to a permanent magnet fitted at the other
end of the balance arm. The permanent magnet switches a reed contact that is
fitted in a sliding tube outside the medium. The tube is set as a N/O contact at the
factory, that is, the contact closes when the level rises. The switching function is
reversed by moving the tube. The instruments are delivered in standard sleeves
for side installation. PTFE tape is used to seal the switch.
6. Mechanical Connection
The float switch is to be attached in such a way that the float can move freely
over its entire range and must not come in contact with the walls, bottom, or
cover of the container. Positions, where turbulence may be encountered, due to
agitators or intake valves, are unsuitable for proper operation.
The container should not have freely moving solids or ferrite particles, since these
will deposit on float magnet- resulting in disturbance in switching process. If the
liquid contains sediments or suspended materials, special care must be exercised
in order to keep these materials away from the float system.
The switch should be attached to the system while keeping in mind the need for
easy access for installation and maintenance.
Ensure that the permitted max. operational pressure and temperature limits are
not exceeded.
Make sure that no remains of packing material exist inside the unit.
The installation position must be horizontal.
If possible, examine all the connection joints for proper sealing, just after
mechanical installation.