As we have discussed in previous articles, there are several types of PV connectors available today. These connectors are found on the positive and negative module whips and are used to connect modules into series strings. PV connectors are also used to form the DC home-run to the inverter. In systems using DC optimizers or microinverters, PV connectors are used to connect the module to the module-level device.

To maintain code compliance it is imperative that PV connectors are UL rated for interminability. In recent years, this required little forethought as the majority of modules came from the factory with common connectors like Staubli MC4 or Amphenol. Change is afoot. Today many module manufacturers have turned to generic PV connectors. Furthermore, some string combiners and inverter DC wiring boxes are now offered in pre-wired configuration with PV connectors already in place. Although these connectors are fully inter-matable with their MC4 and Amphenol H4 counterparts, in most cases the union between these connectors is NOT a UL rated connection. Many inspectors have begun to notice this discrepancy which forces contractors to find a solution.

PV connectors make and model is commonly listed on module data sheets. If you see “MC4 compatible” then you are most likely dealing with a generic connector. Contact your Greentech Renewables account manager for confirmation.

To maintain a code-compliant UL rated PV connection you have a couple options. If the system employs a standard string inverter the easiest remedy to the connector conundrum is to purchase extra connectors (or pre-wired whips) to match the connectors found on the modules. Your account manager can assist you in identifying and procuring these connectors. These extra connectors will be used to maintain a UL rated connection on your DC home-run.

If you prefer to not purchase additional generic PV connectors some manufacturers will provide warranty addenda allowing for the removal of factory PV connectors. The connectors of choice could then be crimped to the module whips. If you choose this strategy only the leads at your string termination would require replacement.
 

Although rare, some electrical inspectors may take issue with generic connectors intermated with MC4 or H4 connectors of popular MLPE devices (see below). If you find yourself in this situation, the use of jumpers (generic on one end, MC4 on the other) is not the best solution. Adding additional hand-crimped connections to the system will increase the potential points of failure on the roof. A better solution is to work obtain written permission from the module manufacturer to replace the factory connectors with connectors to match the MLPE whips.