Motor Control Education Questions

Don't confuse aan "e-stop" with a "process stop". An e-stop by definition will open the circuit effecting the stop. To restart, the e-stop actuator has to be pulled back out/twisted AND a second button pressed to initiate a start. Whether or not safety relays are required will be determined by the risk assessment for the given application. A process stop is just a glorified switch - one position for off and a second position for on. These were common place in design decades ago but are rarely seen in any new industrial application.

For motor starter and connections, drives, wiring etc, this is my bible:
http://www.moeller.net/en/support/wiring_manual.jsp

Go to chapter 2.