WIKA BGU-...I Serie Betriebsanleitung Seite 48

In the event of capacitive load, cable lengths over
50m or connection to process control systems with
capacitive entry a protective resistor of 22 should
be connected in series to limit the peak current.
In case of inductive load the magnetic switches should be protected with
an RC element (see Annex), or a free-wheeling diode. Use of variable re-
sistors as a protection circuit is not permitted because the reed contact
can be destroyed by peaks.
5.5 Commissioning
Prior to commissioning the magnetic switches should be placed in starting
position. To do this slowly move the bypass level indicator float in the in-
side of the pipe from the bottom to the top and then back down again. If
this is no longer possible the float can also be moved from the bottom to
the top on the side of the magnetic switch and then moved back down to
the bottom again. Note the "top" label on the float. In the event of later at-
tachment of magnetic switches these should be set in their starting posi-
tion in the same way. A permanent magnet with any radial polarity can
also be used in place of the float.
As a result of the bistable switching behaviour of the magnetic switch
these must be set to retire as described prior to commissioning. Otherwise
there is a risk of a faulty switch function from an incorrect contact position
when switching on for the first time in the downstream control.
48
Warning!
Operation of the magnetic switch on inductive or capaci-
tive load can result in destruction of the reed contact. This
can lead to a malfunction of the downstream control and
cause personal injury or property damage.
KSR KUEBLER Operating instructions Bypass magnetic switch - BGU-...I