Module connectors

Positive, negative and joined MC4 connectors depicted with wiring.

PV modules are installed outdoor and exposed to the elements, therefore any connections made with PV modules should be water-tight. PV modules are typically connected to one another, or to a wire that goes to a combiner box, with specialty connectors designed for us with PV modules exposed to water and sun. These connectors are designed to to be crimped onto wires using a specialty crimper. They can then be easily snapped together, but typically require a tool to separate them once connector to avoid accidents. The most common type of connector on the market, which typically comes pre-installed on PV modules, is called a Multi-Contact 4 (MC4) connector manufactured by Staubli. There are other different connector designs on the market and many cheaper versions of MC4 connectors that are are not all compatible with one another. If not using original Staubli MC4 connectors, it is important that all of the connectors used are of the same kind to ensure compatibility and avoid high resistance connections that can lead to failures or fires. It is also important that a crimping tool designed for use with the specific type of connector is used.