One of our readers wrote: "We install a number of different types of safety switches on our machines, all we believe, in accordance with applicable standards that were in force at the time. We aren't called on to do regular upkeep or updating of the machines very often. We're a little concerned that as time goes by, and users change out components, the original safety design might be compromised. We're thinking about designing in redundant switches up front to forgo future, unforeseen problems and liabilities. We'd like some thoughts about whether the added costs provide more peace of mind for us as OEMs?"
Send us your comments, suggestions or solutions for this problem. We'll include it in the September '13 issue, and post it on ControlDesign.com. Send visuals if you'd like — a sketch is fine. E-mail us at RealAnswers@putman.net. Please include your company, location and title in the response.
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