Wiring practices

Wire nuts, leaving extra copper, leaving extra wire.

1. If exposed to physical damage, a wire should be protected by some type of conduit or should be relocated. Physical damage can result from contact from persons, animals or the enviroment.
2. All wires should have extra length left in junction boxes or at any point where a connection is made. This serves many important purposes:

• To prevent damage from the accidental contact with a person that may move the wire. An overly tight wire exposed to tension may immediately break free from its connection and cause a fault or fire.
• To allow for expansion and contraction of wire and conduit resulting from heating and cooling.
• To provide extra wire that enables safe working conditions in the future.

1. All connections made with wire should be done with some kind of mechanical connection, like a wirenut, busbar or PV module connector. Connections performed solely with electrical tape - as is common practice in many parts of the world - are far more likely to fail and cause issues.
2. All wires that are entering a connection (busbar, should leave some copper exposed to ensure that insulation is not entering the connection. Insulation in a connection can create resistance, heat and ultimately a fire.