Principles of installation

There are certain important principles that apply to the design and installation of an electrical system regardless of where it is being installed. These core principles are embedded in the electrical codes of every country as they are vital to ensuring user safety, preventing fires, and ensuring that a system functions properly. They will be presented here as general principles with the hope that they may serve as a reminder during system installation. Nonetheless, it is still necessary to check the electrical code for the country on the proper practices for the specific situation or materials under consideration.

1. All system equipment should be protected from unauthorized access to prevent children and anyone who lacks sufficient understanding of the system from accessing live equipment or improperly operating the system.
2. All uninsulated current carrying components of a system (busbars, connections, overcurrent protection device) should be appropriately protected from accidental contact inside an enclosure.
3. All components of a PV system should be installed in accordance with the specifications supplied by the manufacturer, their weather rating and certifications. This includes equipment clearances. Improper installation of equipment is one of the primary causes of safety and performance issues with PV systems.
4. 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.
5. 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 may immediately break free from its connection and cause 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.
3. All connections and fasteners should be properly tightened. Every connection or fastener will have specifications for how tight is appropriate. If lacking appropriate tools for measuring the tightness of fasteners - like a torque wrench or screwdriver - it is ideal to attempt to gain this knowledge from another person or by using these tools in a training context. Connections that are too loose can create resistance, heat and ultimately cause a fire. Connections that are too tight can damage equipment and create similar problems.