Kobold NBK-ATEX, Operating Instructions Manual

Page: 16 / 57

NBK-03 to -33 ATEX
page 16 NBK-03 to -33 ATEX K10/0322
8. Commissioning
Because of the setting behaviour of seals, all screw connections must be
retightened.
Fill vessel and switch on electrical controller, if available. If there are gate valves
between bypass process connection and tank, first slowly open the upper valve
(pressure equalisation) and then the lower valve (liquid side). If vent and drain
valves have been installed, close them before filling.
The liquid that now enters the bypass tube raises the float until the level between
tank and bypass tube is balanced. The roller indicator indicates the liquid level.
Commissioning electrical reed switches NBK-RA
Function of switches
All switches have three connection poles (black (2), blue (1) and brown (3)).
The black wire (2) is the common pole for both switching functions
(N/C and N/O contact).
The float must pass the switch once in both directions so that the switching function
is in line with the terminal connection diagram and table below.
These instructions are often ignored when an alarm lamp is connected directly with
the result that the alarm lamp incorrectly indicates a fault.
When the switch has been passed, it is ready for operation and requires no
maintenance.
black (2) / blue (1) black (2) / brown (3)
float above open closed
float below closed open
Hysteresis
Hysteresis is the difference between contact closing and opening points. A
hysteresis of approximately 15 mm float travel is achieved by factory tuning of the
float magnet and contact strength.