5-Minute Interview: Bill Whitlock
The National Systems Contractors Association (NSCA) tasked Bill Whitlock, an advocate of proper electrical grounding practices, to investigate the electrocution of a pastor in Waco, TX. Reverend Kyle Lake, 33, was fatally electrocuted while standing in a baptismal font after touching a wired microphone.
Bill Whitlock, president, Jensen Transformers Inc., a Chatsworth, CA-based audio transformers manufacturer. The National Systems Contractors Association (NSCA) tasked Whitlock, an advocate of proper electrical grounding practices, to investigate the electrocution of a pastor in Waco, TX. On Oct. 30, 2005, Reverend Kyle Lake, 33, was fatally electrocuted while standing in a baptismal font after touching a wired microphone.
Pro AV:For years, you've been a leader in the effort to educate the pro AV industry about safe and proper grounding techniques. Have we gotten the message yet?
Whitlock: Clearly everyone hasn't. That's something I try to do by getting hooked-up with as many trade organizations and I can. I try to speak at recording studios, schools, universities, trade organization meetings, trade shows — anywhere I can get the message out. Safety has to be consideration No. 1 when you put in a system.
Pro AV:What caused the incident in Waco, TX?
Whitlock: Nearly a year and half ago, the church had replaced the water heater that was a part of the system for the baptistery. But when it was replaced, neither a ground fault circuit interrupter nor the required safety grounding was connected. A year and a half later it developed an internal failure, which is fairly common with electrical heaters. The metal covering on the outside of the heating elements corrodes and allows water to get into the insulation, which separates the 220 V heating element from the water. When that happened, the water became energized. The report I saw said they found 85 VAC on the water with respect to the safety ground in the building. Anyone standing in the water would have been safe as long as they didn't touch anything else to complete the circuit. But when the pastor was in the water up to his waist, the congregation couldn't hear him, so someone handed him a mic that was connected to the house PA system. It was properly grounded, but that completed the circuit. As soon as he touched the microphone, he fell over backward. He was taken to a local hospital and was pronounced dead by fatal electrocution.
Pro AV:What are the most important things contractors and systems integrators can do to ensure that tragedies like this never occur?
Whitlock: No. 1 is to never violate the safety grounding. The most popular way is the three-to-two prong adapter that people stick onto the end of a cord that has three prongs, and plug it into an outlet with only two of the prongs. This defeats the safety ground. Some people will actually take a pair of pliers and wrestle the third pin out of the plug, and then plug it in the wall. That's even more dangerous. The basic rule is if it came with a third prong on the power cord, the connection is absolutely required for safety. AV equipment kills about 10 people per year in the United States, according to the Consumer Products Safety Commission. Some of those deaths are a result of ground lifting. It's also important to check the wiring of all of the outlets. Never assume that everything is wired correctly.
Pro AV:Do you think a house of worship install is a special case because non-professionals are often involved in the installation and operation of AV systems?
Whitlock: I think in the case of churches there are a higher percentage of laypeople operating the system, and unfortunately it also appears that there are a high number of those people doing professional work with wiring water heaters. I'm not sure that was the case in this situation, but sound systems are frequently put in by volunteers because churches are often strapped for money. The problem is that these people are vulnerable to a lot of myths in the industry. For example, if you search the Web, you'll still find a lot of websites that say that removing safety grounds is OK.
Pro AV:Do you see this incident as an opportunity to continue to raise awareness about safety grounds and other safety concerns in installations?
Whitlock: Yes. Good, accurate information is out there. I'll happily send out my 40-page handout that I use in my seminars, which not only talks about the causes and cures of hums and buzzes in sound systems, but how power lines work and why the safety mechanisms required in code are essential. (For more information, contact Bill at firstname.lastname@example.org.)