Fig. 9 Thermally Unfavorable Arrangement Of The Twinsafe Terminals - Beckhoff TwinSAFE EL2912 Operating Instructions Manual

Operation
EL69x0
The EL69x0 emits a relatively high amount of waste heat, since it has a high internal clock rate and high
logic performance.
EL2904/EL291x
The EL2904/EL291x emits a relatively high amount of waste heat due to the potentially high output current of
the connected actuators.
EL1904
The EL1904 also emits a relatively high amount of waste heat, despite the fact that the external load due to
clock outputs and safe inputs is relatively low.
Thermally unfavorable arrangement of the TwinSAFE terminals
The following arrangement is rather unfavorable, as terminals with relatively high waste heat are attached
directly to the EtherCAT Coupler or the power supply terminal with high E-bus load. The additional external
heating of the TwinSAFE terminals by the adjacent power supply units increases the internal terminal
temperature, which can lead to the maximum permissible temperature being exceeded. This leads to the
diagnosis "Overtemperature" message.
Fig. 9: Thermally unfavorable arrangement of the TwinSAFE terminals
Thermally favorable arrangement of the TwinSAFE terminals
The following arrangement is thermally optimized, as terminals with low current consumption and therefore
low waste heat are attached between the EtherCAT Coupler/power supply terminal and terminals with higher
waste heat.
24 Version: 1.0.0 EL2912