n
Long connecting cables
n
Capacitive consumers
Example of protective measure:
Fig. 30: Protective measure against
capacitive loads
Ohmic loads
There is a danger of high current
peaks from ohmic loads when
switching-on the switch contact. The
reason for this is that the glow filament
has a low resistance at low tempera-
tures. Ohmic loads are caused by,
e.g.:
n
Filament bulbs
n
Motors during startup
Examples of protective measures:
Fig. 31: Example 1
Fig. 32: Example 2
Protection against ohmic loads can be
achieved through installation of a
resistor in the circuit, or by heating the
glow filament. For connection to high-
impedance consumers (ex. PLC), a
protective circuit is not needed.
Installation und initial startup
Contact protection measures
03.09.2018
DWG Module BASICS Flow Monitor
46