![]() see the folowing about typical power company neutral ground wiring and note some special buildings do NOT use the system even on the same power company: The neutral connects to the neutral bus NEVER the ground bus in the panel (USA typical home - you do have to check with your power company for ). If you have no ground (3 wires total for a 240 single phase needing 4 wires total), you have no ground: it's that simple. Also: NEC's circuit never include the appliance circuit (you never expose people to the inside of an appliance - if the appliance has a legitimate NEC ground and you connect to that: then your right). Neutral is NOT basically the same as ground and should NOT be connected to ground (see 1 bad exception below). Now you have 4 wires in the panel and can connect the 14-30 normally. And then retrofit a ground using some cheap, common #8 or #10 bare ground wire from the hardware store, and run that back to the panel via any reasonable route. (Make sure to wrap it with tape so it can't short against the ground or the box). So if there is a bare wire in the cable and it's legal to use it as neutral since it is SE cable, your best bet may be to continue using it as a neutral. In the past, this has been used as neutral (with no ground at all). Where do you get neutral? When a dryer is connected with SE cable, people often assume the bare wires wrapping around the conductors are the ground. However you are much better off connecting a NEMA 14-30, with separate neutral and ground, and removing the neutral-ground tie jumper from the dryer, and supplying that from a GFCI breaker. ![]() However this is the conventional advice - you do this bad idea using a NEMA 10-30 connector. There's a special exception (NEC 250.140) that allows you to connect a dryer this way. It means you need one less wire, but if anything goes wrong with that wire, the chassis of the dryer becomes electrified. Tying neutral and ground together at the dryer is an obsolete and dangerous technique. Feel free to ask additional questions, or point out mistakes in the comments below. If I've missed anything, or haven't explained something properly. If a proper 4 wire cable existed, the schematic from above would look something like this. That is defiantly a code violation (NEC 2011 406.5). If the receptacle is not of the self-contained variety, and is not in a box. Which is why this code exception is only valid, if the conductor is insulated.Ĭonnecting a dryer in this way will work, but is a potentially dangerous code violation (according to the National Electrical Code). If this is not the case, your installation may still be a code violation.Īn uninsulated, normally current carrying conductor running through your walls is typically a bad thing. If you read point number three of the exception to section 250.140 of the National Electrical Code, you'll find that the neutral must be either insulated, or part of a Type SE cable. When the wiring is connected to the proper device, the third wire in the cable becomes a grounded (neutral) conductor, and the code may be satisfied. In the case of a three wire circuit, a NEMA 10-30R device should be installed. However, connecting a NEMA 14-30R device in this way is nonstandard, and a code violation. ![]() The dryer will work just fine whether the N terminal is connected to a grounded (neutral) conductor, or a grounding conductor. Extending this image further, we can see how the dryer connects to a 120/240V split-phase system using a 3 wire cord.ĭue to the nature of the 120/240V split-phase system, the grounded (neutral) and grounding conductors in a dedicated single appliance circuit are basically the same. Notice that all the control circuits are 120V components, and that basically only the heater is 240V. Here is a highlighted image of a random electric dryer schematic. ![]()
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