how to install four wire power cord for use in a mobil home
With four wires the green ground wire from the cord is connected to the dryer frame. The green ground wire in the dryer grounds to the frame, which then grounds everything thorugh the cord. The white wire goes in the middle of the three wire connections on the connection block, the others on the ends.
Here is a brief instruction and photo.
Remember to remove the wire that goes from the center terminal of the block to the frame. This is only used in 3 wire hook-ups.
The green (earth ground) of your 4 wire will now hook to the frame and the white (Neutral) will hook to the center terminal.