Sometimes, choosing a component is up to the customer’s discretion. Sometimes, it’s based on the application. And sometimes it’s just what the machine builder is most familiar with. With relays, there are a few clear-cut ways to go, but many times it’s a matter of trade-offs. Choosing between electromechanical relays (EMRs) and solid-state relays (SSRs) is sometimes more difficult than you get credit for.
This panel of industry veterans will give you a few insights that might remind you of some basics you already know and could help you make a more-informed decision on your next machine.
Meet the panel
Thomas Stevic is controls engineer at Zed Industries, a thermoforming and plastic packaging machine builder in Vandalia, Ohio.
Stephen Kirk is project manager at Industrial Automation Group, a system integrator in Modesto, California.
Michael P. Collins is president of MPC Management, a consulting company in Portland, Oregon.
Danny Weiss is senior product manager at Newark element 14.
Kurt Wadowick is I/O and safety product specialist at Beckhoff Automation.
Rafal Pabich is senior product manager at Carlo Gavazzi Automation.
Dan Nigro is product marketing manager, industrial components, at Omron.
Steve Massie is product manager at IDEC.
Daniel M. Loflin is product manager at Siemens.
Tina Lockhart is director of engineering at Moore Industries.
Terry Harmon is offer marketing specialist at Schneider Electric.
Rick Frauton is senior product marketing manager at United Electric Controls.
Tom Edwards is senior engineer at Opto 22.
Traci Bretz is relay product marketing specialist at Phoenix Contact USA.
In which applications are electromechanical relays (EMRs) still more advantageous than solid-state relays (SSRs), and why?
Stevic: EMRs have several distinct advantages over SSRs when it comes to the power/cost ratio, switching voltage capabilities, power dissipation characteristics and failure mode. An EMR with a rating of 30 A can be had for as little as $10, where an SSR of the same power handling capability will cost about four to five times as much.