Replies

1. 
   pm22 | Jul 08, 2008 03:48am | #1

   You do not count the ground wire. Therefore, 14-2 means one hot and one neutral [usually] that is the white wire and then a ground wire [bare] 14-3 has three current carrying wires: black, red and white.

   For a 220 volt appliance, which uses 220 volts only, you only need two wires. The white wire is taped red at both ends and is attached to both poles of the double breaker.

   For a 220 volt appliance such as a stove, which may have a timer or light running off 120 volts, you would need a neutral. Therefore you would use 3 wires. The red and black go to the poles on the breaker and the white goes to the neutral bar where it orders a beer.

   ~Peter

2. 
   markmoro | Jul 08, 2008 03:54am | #2

   The number of conductors is relative to the load you are feeding. If the appliance has 120 devices such as timer motors or lights then you will need to have a grounded conductor (neutral) in addition to the 2 line conductors and the ground. Air-conditioning compressors and hot water tanks which are straight 220 volt only require the 2 line (hot) conductors and a ground.

    Additionally, if your jurisdiction has adopted the 2008 NEC you will now have to protect multiwire branch circuits (2 hots sharing a common neutral) which are only 120 volts each with a 2-pole breaker to disconnect both the hots for servicing.