Allen-Bradley 1794-IB16D Installation Instructions Manual page 5

FLEX I/O Digital Input and Output Modules with Diagnostics 5
WARNING: When you insert or remove the module while backplane power
is on, an electric 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 electric 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.
WARNING: If you insert or remove the module while backplane power is on,
an electric 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.
Publication 1794-IN096D-EN-P - June 2018