![]() ![]() No other cable type is allowed a bare neutral. 30-50A SE cable went obsolete because power companies no longer offered service that small). (SE cable is nominally for Service Entrances hence SE which is on the utility side of the main disconnect, so ground doesn't exist yet. Insulated white wire - except for the odd case of SE cable, which has a bare mesh neutral and outer sheath rated to insulate that, so a "naked" white wire if you will. So, in practice were these wired with an insulated white wire (neutral), or were they wired with a green or bare ground? This confusion is why it was explicitly outlawed in 1996. However, there were enough nitwits (including nitwit inspectors) who misinterpreted this rule, doing "/2 w/ground" and abusing NM ground as neutral, which it isn't rated for. Once those stocks of obsolete wire were gone, the only legal choice would be /3 w/ground cable. SE cable has a bare neutral, but its insulation is rated for that. In 1966 when the exception was made for dryers and ranges, the idea was to let suppliers "use up" their remaining stocks of 30-50A "/3 no-ground" and SE cable, since these were functionally obsolete the moment NEC 1966 dropped. In fact, it has always been illegal to use /2+ground cable to wire a dryer. Actually they were correctly wired (per pre-1996 Code) and the neutral wire simply got loose, energizing the chassis. Usually reported as mis-wired outlets, because the news cribs off court dockets, and that's what plaintiffs allege. Slowly, data rolled in showing that assumption was developing a body count. What is happening is that NEC allowed (from 1966 to 1995) attaching the dryer's chassis to neutral on the logic that neutral rarely fails because those sockets are rarely disturbed. However, 10-30's neutral doesn't double as a ground at all. If one wanted a socket with no neutral, for a compressor, welder, EV charger and the like, the NEMA 6-30 is the socket for that. That's the purpose of the newer 14-30 - adding a ground to the 10-30 that didn't have one. NEMA 10 is clearly defined.īut its my understanding that a 10-30 has only a neutral that doubles as a ground, and there is no independent ground. Someone is wrong, and probably violated Code when they did their installations, and are engaged in vanity defense. Someone is telling me that old dryer outlets are wired with a ground and no neutral And the "master panel" where all the breakers are, will show separate N and G. ![]() It's a sad practice because it makes it impossible to clamp an ammeter around the equipotential bond wire to detect current moving on it.)įortunately, NEC 2020 calls for a main breaker at the meter, which has the side effect of moving the N-G equipotential bond to the meter-main. (rather than the formality of totally separate bars with a connecting bond wire, builders are allowed to toss circuit grounds on the neutral bar. However, the way this bond is implemented confuses the hell out of people. Neutral and ground are totally separate systems that don't connect anywhere, except for a deliberate equipotential bond in the main panel. ![]()
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