Rockwell Automation 1758-RTU202 DataSite Hardware User Manual - Manual (Page 14)

Publication 1758-UM001D-EN-P - June 2011
14 Installing the Controller
Disconnecting Main Power
The main power disconnect switch should be located where operators and
maintenance personnel have quick and easy access to it. In addition to
disconnecting electrical power, all other sources of power (pneumatic and
hydraulic) should be de-energized before working on a machine or process
controlled by a controller.
Safety Circuits
Circuits installed on the machine for safety reasons, like overtravel limit
switches, stop push buttons, and interlocks, should always be hard-wired
directly to the master control relay. These devices must be wired in series so
that when any one device opens, the master control relay is de-energized,
thereby removing power to the machine. Never alter these circuits to defeat
their function. Serious injury or machine damage could result.
WARNING
Explosion Hazard
Do not replace components, connect equipment, or disconnect
equipment unless power has been switched off.
WARNING
Explosion Hazard
Do not connect or disconnect connectors while circuit is live.