• This knob is the timing mechanism of a clothes dryer.laundry dial image by Sirena Designs from Fotolia.com
  
  Clothes dryers are available in two main types: gas and electric. Both of these styles require electricity; the gas dryer simply requires less. Your clothes dryer will have specific requirements, both based on whether the dryer is electric or gas, as well as what year in which it was produced.
  
  

Gas Dryer Connections

• Gas dryers dry clothes using a gas-powered heating device. The greatest amount of power is derived by the gas connection. The gas dryer does, however, require an electrical timing piece that must be connected to an electrical outlet. Gas dryers use a typical three-pronged outlet that can hold 120 volts.
  
  

Electrical Dryer Connection

• The electrical dryer derives all of its power from electricity. Because of this, the plug is a large 240-volt connector that must have a separate outlet and breaker on your circuit breaker box. The plug is either made with three prongs (circa prior to 1996) or four prongs (post 1996). The fourth prong, a ground wire, was added in 1997 to reduce the risk of electrocution. The three-prong plugs have two slanted, slender prongs and a rounded prong in pyramidal orientation. The four-prong plugs consist of an L-shaped prong, two slanted, slender prongs and a rounded prong. Both plugs must have receptacles that identically match their plugs, on a separate line to a separate breaker pole on your circuit box.
  
  

Electric Power Cord

• The power cord for electrical dryers is specifically made to handle the volts supplied to the dryer. The cord must be UL certified, meaning it has been tested with success by the globally trusted Underwriters Laboratories. The cord should be at least four feet long to avoid shock from device to breaker box, and must be 30 amps and 120/240-volt specified. Modern cords have four wires, yet when wiring a three-prong dryer you simply leave the ground wire (either bare copper or gray coated) unconnected.