FM Frequency: A Shock To The System?
By Jeff Crane, P.E., LEED® AP
Published in the December 2003 issue of Today's Facility Manager
From an early age, I have enjoyed taking things apart and either learning about how they work or trying to fix them when they break. As a youngster, I remember prying the backs off watches, examining the guts of toys, removing springs from ballpoint pens, and even smashing light bulbs just to hear them pop. Biology, chemistry, and physics classes and labs in high school and college further encouraged this fascination that ultimately lured me toward an engineering curriculum and a facilities management career.
My first exploration with electricity came when I was five or six years old. I was on a camping trip with my family, and that meant sleeping on the hard ground in a tent in western New York. Nighttime temperatures (all year) rarely exceeded 40°. We camped at sites with power and water service and usually brought a little electric heater for the tent,the kind you won't allow in your buildings!
Anyway, one night I remember attempting to plug the heater into the extension cord that ran to the site's power pole. One of my fingers got caught between a prong on the heater's plug and the female connector on the cord. If you've ever touched 110 volts (I don't recommend this), you're probably familiar with the little pulsing vibration that alternating current sends through your body until you scream and let go of whatever you're touching. That experience scared the heck out of me, and I've been intimidated by electricity ever since.
I've made a few other mistakes with electricity. In college, I blew up a Fluke meter and tripped a circuit breaker trying to measure resistance (Ohms) across an outlet-bad idea. That same year, I had a brush with 208 volts while wiring a pump for a research project. (I don't recommend this). Comparing the sensation of 110 volts to 208 volts is like comparing the grips on a lawnmower handle to a jackhammer! Needless to say, my respect for electricity has grown over the years.
I have recently taken short courses on wiring and controls to confront my fears and become a more effective (and safe) troubleshooter. I almost feel comfortable navigating wiring schematics and using a multimeter to trace circuits and find problems. My first boss used to say, "Jeff, electrical engineering is simple-it's just connect the dots!" I think I know what he meant, but until I can actually see an electron moving through a wire, it's an enigma to me.
Last week, I had another incident that reminded me why I decided to become a mechanical engineer and stay away from the nasty electron conspiracy. We had a pretty major event planned in my facility on Monday evening, and when I came in from the weekend we had two malfunctioning atrium light circuits. We use programmable light timers on these 277 volt circuits, and unfortunately, they don't seem to last very long. Two of the eight timers needed to be replaced. As a hands on, frugal facility manager, I knew I might not find electricians on such short notice and decided to do it myself.
I got the tools and parts for the job and diligently checked the electrical drawings to identify the circuits that needed to be isolated. I tagged out the two circuits in the electrical panel and proceeded to take the plate cover off the box (there were four circuits in this box), carefully removing one of the bad timers. Before touching any of the wires, I checked the leads with my meter twice-all dead. I re-read the instructions on the timer and confirmed the wiring I just removed was actually correct. I used wire nuts to make the new connections. I carefully replaced the second timer in a similar manner and put the timers back in the box. I took a deep breath, relieved that the hard part was over, and set the clocks and on/off programs.
Before I packed up my tools, I turned on the breakers to be sure everything worked. I went back to the timers and turned on the first one. Bingo, the circuit lit up as planned! When I turned on the second timer-nothing-no lights. Oh great, now what?! I knew I had the right circuits and thought one of the wire nuts must have come loose behind the timer. I unscrewed the timer and gently removed it from the box. Sure enough, one of the wire nuts only had one wire in it. I started to draw the loose wire out when-POOF-the loose wire touched the grounded box and tripped the circuit breaker. It scared the heck out of me but the breaker did exactly what it was supposed to do by immediately killing power to the circuit. The timer was understandably fried (can you say "burnt electrical" smell?) because of the voltage surge so I had to replace it. I tagged out the circuits again and replaced the dead timer. I made sure the wire nuts were tighter this time and gently replaced the switches. I went back to the electrical room, energized the circuits, reprogrammed the timers and lit up the atrium-perfect!
Even though I felt good about making that repair myself and having full lighting for our event, I felt pretty sick the rest of the day about the mistake I made. I should have known not to pull that timer without first de-energizing the breaker-dumb mistake.
I consider myself extremely strict when it comes to site safety, especially with my nemesis, electricity. I won't let electricians work in hot panels or do anything in my building without double and triple safety inspections by them and me. I'm also a huge advocate of strict lock out/tag out procedures.
Needless to say, I learned a valuable lesson this week and hope everyone will benefit from reading this. Be careful out there! Make sure you, your staff, and your contractors are adequately trained and are following proper safety guidelines, even when performing seemingly simple tasks.
We facility managers have an opportunity to continue the quest for knowledge and literally put their hands on technology from yesterday and today while dreaming of (and shaping) the technology of tomorrow. Think about it; we have daily interaction with software, hardware, generators, air conditioners, pagers, mobile phones, cooling towers, circuit breakers, valves, lighting, plumbing, roofing, doors, windows, asphalt, and just about everything in and around a building that rotates, blinks, flows, or otherwise does something useful!
With that opportunity comes the awesome responsibilities of site safety. We must do everything in our "power" to protect people.
Have a happy and safe New Year!
Crane is a mechanical engineer and regional property manager with Childress Klein Properties, a leading real estate developer and property management services provider in the Southeast.
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