Electrical Troubleshooting Quiz

There's been talk of layoffs. In response, production managers have produced several productivity initiatives. But another response has also arisen, and it's not good. During routine maintenance, techs are finding jumper wires across the terminals of various switches that stop machines for safety purposes. Fortunately, the only related injury thus far occurred when a production worker got her arm bruised.

Because production workers see the safety devices as getting in the way of keeping their jobs, talking to them doesn't work. Corporate HR sent out a memo instructing maintenance to do daily inspections of the machines. This approach would require far more staffing than you currently have, and would not guarantee a switch somewhere won't be bypassed. What are some options for solving this problem?

You'll have to use a multi-pronged approach. Here's a list of suggestions to consider:

• Lock. Where possible, mount vulnerable devices in lockable boxes.
• Virtualize. You might eliminate some discrete switches by moving their functions into software. However, you can't do this with, for example, a permissive limit switch that detects when a safety barrier is fully extended.
• Detect. Add a detection circuit that requires a switch to change position for the control logic to issue a permissive.
• Show. Contact vendors of safety devices and safety controlled equipment, and ask about videos you can show the operators.
• Watch. Install hidden surveillance cameras. What's available today is formerly James Bond kind of stuff.