Technical Data; Overload Protection; Fig. 23 Overload Current Limitation; Fig. 24 Schematic Illustration Of The Thermal Switch-Off In Case Of Overload - Beckhoff EL28 Series Documentation

Product overview
2.5.4

Overload protection

Technical data

Please note the information in the technical data regarding load type, max. output current and short
circuit current.
When switching on lamp loads, high starting currents occur that are limited by the output circuit of the
terminals (see fig. Overload current limitation).
Fig. 23: Overload current limitation
Fig. 24: Schematic illustration of the thermal switch-off in case of overload
In case of a long-term overload and/or short-circuit, the output is protected by the thermal switch-off of the
channel.
The output circuit of the terminal limits the current. The terminal maintains this current until important self-
heating of the channel occurs.
On exceeding the upper temperature limit, the terminal switches the channel off.
The channel is switched on again after it has cooled down to below the lower temperature limit.
The output signal is clocked until the output is switched off by the controller or the short-circuit is eliminated
(see fig. Schematic illustration of the thermal switch-off in case of overload). The clock frequency depends
on the ambient temperature and the load of the other terminal channels.
32 Version: 2.2 EL28xx-xxxx