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.
