You can replace the 3-wire cord with a 4-wire. The extra wire provides a separate ground wire. So, you've got 2 hot wires, 1 neutral, one ground. Usually the ground wire attaches to a screw on the frame.
If they have colors, black or red is hot, white is neutral, green or bare is ground.

[This message has been edited by rpxlpx (edited October 11, 2002).]

Thanks.

Ben,
When you install the new 4 wire pigtail be sure to remove the jumper that connects the frame of the range to the white wire terminal on the 3 wire setup. If you don't do this you have defeated the added safety of the separate grounding (green) wire and at the same time created a ground loop which creates a hazard.

Help! I am an idiot with electrical stuff. I have the same problem and can't understand the answers here in this thread. I bought both the wall outlet and the 4 prong pigtail. I tried to replace my 4 prong wall outlet with a 3 prong and could not understand what to do with the negative wire. So I put it bsck togather and tried to put the pigail on and was unsure what wires went where? HELP!!!

Please contact a licensed electrician and ask for an on site inspection of the proposed installation.

The 2002 national electrical code requires a 4 wire circuit to be run for electric ranges and electric clothes dryers for new work, and for old work 3 wire cords and receptacles can remain for existing 3 wire circuits only.

Playing around with electricity is like fighting fires, I am sure you know what I mean.