you must connect the chassis to a reliable earth ground using the ground lug (provided) and size awg 6 (13 mm2) wire.
perform this procedure to connect the chassis to ground.
step 1 strip one end of the ground wire to expose approximately 0.75 in. (20 mm) of conductor.
step 2 crimp the ground wire to the ground lug, using a crimp tool of the appropriate size.
step 3 attach the ground lug to the chassis as shown in figure 3-39. use a number 2 phillips screwdriver and the screws supplied with the ground lug.
step 4 connect the other end of the ground wire to a suitable grounding point at your site.