Dr; I've seen properly covered copper powerline wires that were well over 50 years old, and underneath the cover, the copper was "squeeky clean". It's only when bare and under harsh envirnonmental conditions, ie high temperature and humidity that corrosion is a serious problem. And I agree with Unsound above, periodically clean copper contacts and they will work well for many years.
My copper house wiring is 33 years old, and in the main breaker box, the exposed wire ends only have a VERY thin layer of oxidation, ie they look somewhat dirty as opposed to shiney-- and I live in a high humidity (but cool) area. If properly taken care of, your copper wires will outlast you and me. Cheers. Craig
My copper house wiring is 33 years old, and in the main breaker box, the exposed wire ends only have a VERY thin layer of oxidation, ie they look somewhat dirty as opposed to shiney-- and I live in a high humidity (but cool) area. If properly taken care of, your copper wires will outlast you and me. Cheers. Craig