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## [TowerTalk] 220VAC circuits

 To: [TowerTalk] 220VAC circuits rhummel@cheshire.net (Robert Hummel) Tue, 23 Mar 1999 10:48:58 -0500
 ```WHAT COLORS? When using non-metallic cable (NMC), such as Romex(tm), for 110/115/117 VAC circuits, use black=hot, white=neutral, green/bare=ground. GROUND = NEUTRAL? The ground wire and neutral wire in a residential electrical system should be connected together at one -- and only one -- point in the system: where the service enters the house. Thus, if you have a 220V service, your service entry panel will have two hot wires and a neutral coming from the utility company. The panel will be grounded to earth. At that point, the neutral is connected to ground. Connecting the neutral and ground together anywhere else but the entry service will result in a potential difference being impressed across the ground wires throughout the system in case of a short -- a dangerous situation. 3 vs 4 WIRES? As wiring is distributed, to a sub-panel for example, the neutral and ground must be carried seperately. So a subpanel with 100A service would use #2 cable with 3 conductors and a seperate ground wire. Do not use the ground wire as a neutral. In general, it is a smaller wire and does not have the current carrying capability of the main conductors. SPLITTING CIRCUITS If you want to run both 220 and 110 off a single wire, you must use 12/3 + ground. This gives you two hot wires (one for each phase) and a third to function as the neutral return for the 110V circuits. Any pure 220V connections on the line will ignore the neutral wire and connect between the two hot wires. If you don't run 12/3, you can't "split" the circuit. For example, I run 12/3+G to a quad box near my table saw. The box has a 220V (across the hots) outlet and two split 110V (break the bonding bar on the duplex outlet) outlets. An overcurrent condition in any of them will trip the 220V bonded breaker. WHAT SIZE BREAKER? The function of circuit breakers is to protect the wiring, not the device plugged in. You must rate your circuit breaker to protect the smallest wire in your circuit. If you run all #12, for example, but have a short section of #14 to an overhead light, you must install a 15A breaker to protect that wire. -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com Search: http://www.contesting.com/km9p/search.htm ```
 Current Thread Re[CQ Contest}RE: [TowerTalk] 22VAC to 2 110VAC circuits, Tony Kazmakites Re[CQ Contest}RE: [TowerTalk] 22VAC to 2 110VAC circuits, Dan Arney [TowerTalk] 220VAC circuits, Robert Hummel <= Re[CQ Contest}RE: [TowerTalk] 22VAC to 2 110VAC circuits, Mike A. King Re[CQ Contest}RE: [TowerTalk] 22VAC to 2 110VAC circuits,