Install Or Remove The Module Under Power - Allen-Bradley E Series Installation Instructions Manual

14 ControlLogix ControlNet Interface Module

Install or Remove the Module Under Power

You can install or remove the module while chassis power is applied if you
observe the following precautions.
When you insert or remove the module while backplane power is on,
WARNING
an electrical arc can occur. This could cause an explosion in hazardous
location installations.
Be sure that power is removed or the area is nonhazardous before
proceeding. Repeated electrical arcing causes excessive wear to
contacts on both the module and its mating connector. Worn contacts
may create electrical resistance that can affect module operation.
Publication
1756-IN604A-EN-P - February 2006