The difference between a three-prong plug and a four-prong plug for a stove, dryer or other 240 volt electric appliance is the addition of a separate ground wire to improve consumer safety. On the three-prong plug, two of the prongs are the hot feed, each providing 120-volts of power, and the third is the ground-neutral wire.Know More
According to About.com, the theory behind the three-prong plug is that electrical panel manufacturers bond the neutral to the ground bar in the box, giving both the same electrical potential. However, in wet locations, such as the kitchen or laundry, the human body becomes a path of least resistance through which electricity flows, increasing the potential for electrocution if there is a fault in the appliance.
In the event of an electrical short, a human touching the machine becomes the path to ground the power takes. If the person happens to be standing on a wet floor, the 240-volts of electricity passes through his body. Even if he survives the incident, he often suffers serious burns.
The four-prong setup includes two hot wires to provide power to the appliance and a neutral wire to return electricity to the circuit panel. The fourth wire is the ground. It provides a low resistance path for the electricity to return to ground in the event of a malfunction, increasing safety for the user.Learn more about Ovens & Ranges
A stove thermostat controls the power that flows to an oven's heating element, allowing the oven to reach and maintain the proper temperature. The thermostat includes a bulb that senses the oven's temperature and turns the heat on as needed to sustain a consistent temperature.Full Answer >
When compared in terms of energy efficiency, a gas stove is much more efficient than an equivalent electric stove. This results in a gas stove costing a user much less to run than an electric one.Full Answer >
Dryers can be converted from three-prong operation to four-prong operation by replacing either the dryer cord or the wall outlet. Most professionals consider changing the cord to be the best method. Adapter cords are available at most home improvement stores, such as Lowe's or Home Depot.Full Answer >
Updates to electrical codes in 2000 require that dryers use four-prong plugs. You can update a dryer to meet these requirements in less than half an hour. The job requires screwdrivers or nut drivers and a replacement power cord.Full Answer >