I am trying to replace an old Hayward TriStar pump with a new one. The old pump had a ground wire connected, but there was no copper wire coming out of it. The new pump does have a slot for the ground copper wire in addition to the slot for my original green ground wire. Will it be not sufficient if I attach just the green wire and not the copper wire just like I had it in the old pump? If not, what is the easiest way to install this copper ground line?