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IB IL 24/230 DOR 1/W
5663BC01
11
Switching AC/DC Loads
Switching Large AC Loads
When switching large AC loads, the relay can be
operated up to the specified maximum values for
switching voltage, current and power. The arc,
which occurs during shutdown, depends on the
current, voltage and phase angle. This
shutdown arc switches off automatically the next
time the load current passes through zero.
In applications with an inductive load, an
effective protective circuit must be provided,
otherwise the life of the system will be reduced
considerably.
In applications with lamp loads or capacitive
loads the current peak should not exceed 6 A
when switching on the load. This guarantees a
lifetime of the IB IL 24/230 DOR 1/W terminal as
high as possible.
Switching Large DC Loads
In DC operation, a relay can switch a relatively
low current compared with the maximum
permissible AC current. This maximum direct
current value is also highly dependent on the
voltage and is determined in part by constructive
conditions, such as the contact distance and
contact opening speed.
The corresponding current and voltage values
are shown in the example in Figure 9.
Figure 9
DC load limiting curve (relay
REL-SNR-1XU/G 5 GOLD LIEG)
An unattenuated inductive load further reduces
the values given here for switching currents. The
energy stored in the inductivity can cause an arc
to appear which passes on the current via the
open contacts. Using an effective contact
protective circuit, the same currents can be
switched as for an ohmic load and the life of the
relay contacts is the same.
If higher DC loads than permitted are to be
switched, several contacts can be switched in
parallel.
Additional technical data is available on request.
I
Switching current in A
U
Switching voltage in V
Definition of the load limiting curve: For 1000
cycles, no constant arc should occur with a
burning life of > 10 ms.
1
1 0
1 0 0
1 0 0 0
V
U
I
0 . 1
1
1 0
5 6 6 3 A 0 1 3
A
