Most homeowners have run into a problem with trying to hook a 3-prong dryer cord up to a 4-prong outlet, or vice-versa, at one point or another. Whether you move into a new home that has a different outlet or purchase a new dryer with a different power cord, this is an all-too-common scenario. Unfortunately, few people understand the difference between 3-prong and 4-prong dryer cords. In an effort to shed some light on this subject, we’re going to discuss the purpose of these cords and why there’s a growing popularity for 4-prong cables.
Up until the mid-1990s, 3-prong outlets were the standard used in American homes. Nearly all homes built before this time featured either a 3-prong outlet or range outlet (slightly different than a typical 3-prong dryer outlet). It wasn’t until 1996 when the National Electrical Code (NEC) was updated to require 4-prong dryer outlets in all new homes. Existing homes may still use 3-prong outlets, as the NEC changes are limited strictly to new homes.
So, why did the NEC make the decision to switch from 3-prong to 4-prong dryer outlets in new homes? Although the old 3-prong outlets were effective at providing power to dryers, they had one major flaw: the ground and neutral wires were grouped together, creating the potential for shock. 3-prong dryer cords contain two ‘hot’ wires along with a third wire that contained both the ground and neutral wire. If a current happened to make its way onto the ground wire, it could travel up to the dryer.
The more recent 4-prong dryer cords feature two hot wires, a neutral wire and a ground wire. This eliminates the possibility for a ground current traveling to the machine, as it features a separate return path for unused power.
The good news is that you don’t have to purchase a new dryer if the current outlet in your home doesn’t match. There are a couple of different scenarios ways workarounds, one of which is to purchase a new dryer cord. Most home improvement stores, such as Lowes and Home Depot, sell both 3-prong and 4-prong dryer cables for about $20-$25 bucks. As long as you have access to a Phillips head screwdriver, you can easily change out the dryer cord. Be sure to install the strain relief that comes with the new cord.