Siemens SIMATIC ET 200SP System Manual page 95

Wiring
6.4 Operating the ET 200SP on grounded incoming supply
Cable temperature measurement threshold
Note
Cable temperature measurement threshold
When choosing a cable, remember that the cable temperature in operation can be up to
30 °C higher than the ambient temperature of the ET200SP system (example: at an ambient
temperature of 60 °C, a connection conductor must be dimensioned for a temperature range
of at least 90 °C).
You should specify other connection types and material requirements based on the electrical
characteristics of the circuits you use and the installation environment.
94
Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ