I have a Roper dryer and the cord that it has does not configure with the plug in on my wall. So I went to Home Depot and the guy that helped me handed me the cord he said I needed and when I got home I took a look at it and noticed that the cord he gave me was a 4 prong and my outlet is a 3 prong. Now my question is... I was told by some people that it is possible to remove the full circle prong and then use it as a 3 prong. Is that correct?
The 4-wire connection includes hot, hot, neutral, ground. The 3-wire connection includes hot, hot, neutral, but no ground. The basic premise is that older houses only had the 3-wire receptacles and since ground is essentially the same as neutral, and dryers are rarely moved/replaced, let the 3-wire connections continue to be used. However, when something goes wrong, having ground the same as neutral can be deadly.
Almost every dryer built in the past 30 years or so can be wired up 3-wire or 4-wire. If it is 3-wire, there is a jumper (short piece of wire and/or a screw in the right place) to connect ground and neutral. If it is switched to 4-wire, that piece of wire or screw is removed.
NEVER mess around with the actual plug. Either use a 3-wire plug with a 3-wire receptacle or, preferably, use a 4-wire plug with a 4-wire receptacle.
It is possible to replace a 3-wire receptacle with a safer 4-wire receptacle. However, the amount of work involved varies quite a bit depending on the particular situation:
- Dryer receptacle near main panel - easy
- Ground wire available, just not connected - easy
- Metal conduit from receptacle to main panel - easy
- None of the above - hard - need to run a new cable (all the wires) and/or a ground wire, or install GFCI protection instead of ground
There are a bunch of questions on DIY about this, such as How to tell if Nema outlets have been successfully brought up to code?