Cheating death as a DJ

July 12, 2017 by Ben Stowe, CTS

This might be one of those times where you might be tempted to kill the messenger, but the irony is that I’m trying to keep you from killing yourself. Literally.

Just about everybody who works in the sound industry has seen (and used) the 3 prong to 2 prong electrical adaptors, often called “Cheater Plugs”. More often than not, they were not used for their intended purpose, but instead for a dangerous and illegal one in lifting the electrical safety ground.

Usually when this is the case, they are employed as a Hail Mary effort to eliminate a hum, often caused by a ground loop. Eliminate the ground, eliminate the ground loop. However, in solving a minor problem we create the potential for some far more serious ones. The electrical safety ground exists for one reason and one reason only. To provide a low-resistance path to ground for electricity, especially in the case of failure. Without the safety ground, you could become the return path to ground, and that could just as well put you IN the ground.

These might seem like strong words, but they are backed by irrefutable fact. 42 year old Professor Tarun Mal was killed in his Cleveland State University lab by using just such a device. The State of Ohio issued the University citations for unsafe electrical conditions following his death, and the coroner stated that had he not defeated the safety ground he would almost certainly be alive today.

Also, as I mentioned earlier, these devices are illegal to use in this configuration. It is clearly laid out in the National Electrical Code in the following sections:

250.6(D) Limitations to Permissible Alterations

and

250.114 Equipment Connected by Cord and Plug

The short summary of these code sections states that “hum” is not sufficiently qualified as an objectionable current to allow lifting the ground and that metal equipment must be connected with a cord bearing a grounded conductor.

So, why do the sell these devices if they are dangerous and illegal? Because when used properly, they actually provide a ground rather than lift it. The device is not illegal, but using it to lift the ground is. The metal ringtab is designed to be connected to a grounded screw on the faceplate of a receptacle. These devices are designed to address an issue from prior to 1968 (nearly a half-century ago) when outlets were not required to have a ground connection. For nearly 50 years, all outlets have been required to have a grounding receptacle, so the usefulness of these little devices is certainly waning.

Solving a ground hum is another article altogether, but in the meantime, please skip the “cheater plug”and cheat death instead.

Ben Stowe, CTS Ben Stowe, CTS (18 Posts)

Ben’s love of electronics and technology led to years of schooling in Electricity, Electronics, Robotics and Lasers. Ben supported himself through school by building and selling strobe lights and other electronic devices. He built his first DJ show largely from scratch and scrap, often repairing broken items others had thrown away because he could not afford to buy new equipment. He holds a Minnesota electrical license, and his AV installs have been featured in almost every major industry trade magazine. His relentless passion for education has led to a number of other certifications and accreditations, including the most widely recognized one in the AV industry, the InfoComm CTS. His love for education inspired him to begin the ProAcademy educational sessions, focused on increasing understanding of AV technologies within the industry. Ben has been involved in a number of technical writings, lectures, presentations, as well as research and development assistance with a number of manufacturers for products, industry wide. He is also a regular contributing author to industry magazines in the United States and Europe. Ben’s presentations have been featured across the world both as a part of industry leading trade shows, and as a presenter for various groups and functions. Some of these events include BPM in the United Kingdom, Mobile Beat, the ADJA National Convention, Wedding MBA, and a national tour as a headlining presenter for an industry magazine. The United States Armed Forces branches have also called upon Ben to provide engineering and training assistance. His highly informational, slightly nerdy and always funny presentation style have made him a favorite at events, while his sincere desire to help people with their application of technology have made him a favorite with them after the event. Ben serves the industry as the President of NLFX Professional, an industry leading supplier of sound, lighting and video systems, a role he has maintained since founding the company in 1993.


Filed Under: Mobile DJ Performance Tips, Sound Engineering for Mobile DJs