A Combiner Box is an electrical distribution box where multiple series of solar PV modules are connected and combined in parallel into one DC output. Combiner boxes used in off-grid systems generally use DC rated breakers. Combiner boxes used in Grid-tie solar applications use 600VDC rated fuses. Please note that fuses, breakers and in some cases fuse holders need to be purchased separately. In order to choose the correct combiner box, it is necessary to determine the number of strings of solar panels, as well as the breaker or fuse size. A typical fuse or breaker size is 15 - 20 Amps.
A lightning arrester is a device used on electrical power systems to protect the circuit and the insulation in case of a unexpected surge in the voltage. Lightning Arresters can also be found as Surge Protectors or Surge Arrester. The typical lightning arrester has a high voltage terminal and a ground terminal. When a lightning or a high voltage surge travels down the power system to the arrester, the current from the surge is diverted around the protected insulation in most cases to earth.
The proper methodology for grounding solar arrays and solar systems is dictated by the National Electric Code (NEC). As a extension of the NEC every equipment manufacturer, specially PV module makers, have their own suggestions for grounding their PV modules. Manufacturer’s suggested grounding practices must always comply with the NEC and UL article 1703. Even though all electrical equipment in a solar photovoltaic system must be properly grounded, including inverters, racking and electrical boxes, PV modules are the main grounding safety concern for inspectors. Grounding lay-in lugs have been extensively used for grounding PV modules; now the use of grounding lay-in lugs is being substituted by grounding clips which eliminates screwing the set screw by just clipping the cable. There is also stainless steel grounding bolts for solar systems installed in corrosive environments. Another grounding practice which has gained a lot of momentum is grounding washers, commonly called WEEBs, which eliminates screwing lugs or clips to individual modules all together. By piercing the solar modules to the mounting rails the WEEBs can properly ground an entire row of solar modules with only one lug, reducing labor and copper cable consumption considerably.
Every day, solar photovoltaic installers struggle with correctly marking their installations in a way that is practical to implement and that meets the expectations of inspectors. The labels in this section comply with NEC requirements, are easy to attach, are durable and resistant to sunlight for years.