Solar Panel Arc Fault

Sma sunny boy us inverters are now available with integrated arc fault circuit interrupter afci functionality.

Solar panel arc fault.

As required by the national electric code nec manual intervention is required to reset the inverter back to normal operation after an arc fault. Unless alternative environmental factors are at play solar panel fires are caused by one thing dc arc faults. Combine the dc arc with a combustable material and fire is the result. The term arc fault refers to a situation in which loose or corroded wiring connections create an intermittent contact that causes electrical current to spark or arc between metal contact points when you hear a light switch or outlet buzzing or hissing you are hearing arcing as it happens.

It is practically impossible for a solar installer to check all of the seals are waterproof preventing water ingress and to also check that all of the cable joints are not corroded and subject to high impedance. It s worth understanding the 3 main types of. Reset an arc fault breaker like you would a standard circuit breaker. Afci in main panel.

Replacing old inverters in an array with older solar panels may result in new arc fault errors. Dc arc faults are quite simply electrical energy flowing through an air gap which in turn creates an electrical arc. Older inverters did not have arc fault detection but new generation inverters do. Arc fault events are a pain point in the solar industry for the threat they pose to pv systems and maybe more so for the detection headaches they cause.

Everyone reading this is nodding along thinking of the times a system they installed was falsely tripped or even worse when an arc fault was completely missed by the detection system. This arcing translates to heat which can break down the insulation surrounding individual conducting. When the sun rises the solar panels start producing power the bare conductors become live causing a dc arc fault and building fire. Integrating afci functionality within the pv system inverter eliminates the cost and effort of installing additional arc fault circuit protection components to meet 2011 nec section 690 11 requirements.