Knowledge is the eye of desire and can become the pilot of the soul.” —Will Durant
Let’s face it — most of us got into this business to get out of having to get a “real” job. If nothing else, we’re here because we enjoy doing more than we enjoy reading and writing.
So it should come as no surprise that some of us can fabricate an entire theatre using nothing but luan plywood and trickline, but when it comes to reading manuals and specs, we’re more of a wooden tiger than Tiger Woods. But that doesn’t excuse us for using a hammer when we really need a wrench any more than using welding cable when we really need feeder cable.
This industry has a history of using welding cable and connectors before proper feeder cable was available for portable applications. In the 1970s and early 1980s, welding cable was the only single conductor cable that was large enough and flexible enough to be used the way only we can use cable. But after the 1984 Olympics in Los Angeles, when a production company asked the City of Los Angeles to allow the use of welding cable and Tweeco connectors, they said “No,” and its use was “outlawed” by the NEC. Most of us got the message and moved on to SC-type feeder cable, which is commonly called “entertainment,” cable and the use of welding cable was largely discontinued.
However, some production companies still pull out the welding cable on occasion, and why shouldn’t they? After all, it’s rated for use with up to 600V, the insulation is rated 105°C, it’s very flexible, its jacket is oil- and weather-resistant and it’s available in AWG sizes up to 500 MCM.
I can think of three very good reasons, however, not to use welding cable for feeder cable.
First of all, it’s disallowed by the NEC. There have been versions of the NEC that specifically disallowed the use of welding cable for anything but the secondary side of a welder. After all, that’s what it’s designed and intended for, and nothing else. I’ve been perusing the NEC lately, looking for those magic words, “welding cable is only approved for use on the secondary side of an electric welding machine,” but that phrase seems to have vanished from the latest version (2008). Either that, or it has been moved somewhere that I can’t find. But that doesn’t mean it’s okay to use it for any other purpose, it only means that they aren’t going to spell it out word by word, letter by letter. You’re smarter than that.
Secondly, the manufacturers of welding cable specify that the cable is “not intended for NEC Article 310 applications or general branch-circuit and feeder wires.” NEC Article 310 is titled “Conductors for General Wiring,” and it describes the requirements for “conductors and their type designations, insulations, markings, mechanical strengths, ampacity ratings and uses.” In other words, the manufacturer is telling you that if you use welding cable for anything other than for welding, then you’re not using it correctly.
The third reason not to use welding cable for feeder cable is that the ampacity of the cable specified by the manufacturer is based on a duty cycle of less than 100 percent, typically 25 percent, 50 percent or 75 percent. That means that for every hour of operation, it’s only conducting for 15 minutes, 30 minutes, or 45 minutes, respectively. So if you use it for feeder cable, then, more than likely, you’re exceeding the duty rating of the cable.
Although the specs for welding cable closely resemble those of entertainment feeder cable, it’s not the same thing. Entertainment cable is jacketed with thermoset, which is a polymer that is cured with heat. Once it’s set, it is very durable. Welding cable is jacketed with ethylene propylene diene monomer (EPDM), which is a type of synthetic rubber. It’s not as durable as thermoset, although it is much more flexible, which is why it’s easier to wrangle than entertainment feeder cable and why some people will ignore the regulations and use it for feeder cable anyway. But in the production environment, with 800-pound stage hands tossing it around like the Minnow on Gilligan’s Island, the insulation is bound to be compromised.
But the best reason not to use welding cable for feeder cable is that there are consequences for misapplying equipment. Should you have a problem and someone ends up getting hurt, or you burn down a venue, then you’ll be held accountable. I’m not a lawyer, but I seem to recall a situation in Rhode Island in which a pyrotechnician used a 15-foot gerb in a 10-foot ceiling at the Station nightclub during a Great White performance. It caused a terrible fire, killed 100 people, and injured 230. When it was all over, Daniel Biechele, the band’s road manager who ignited the pyro, pleaded guilty to 100 counts of involuntary manslaughter. He served two years behind bars and is currently serving out his term under probation. Not only has the incident marred the lives of hundreds of individuals, but now Biechele has to live with the guilt for the rest of his life.
Don’t let that happen to you. If you’re going to use welding cable, be sure to wear welding goggles and gloves and only use it for welding.
