Viridian Solar says that its ArcBox enclosure can be easily snapped around the outside of an MC4 electrical connector. It contains a DC arc within the connector, which prevents fire from spreading to nearby combustible materials.

Viridian Solar, a UK manufacturer of roof-integrated solar panels, has unveiled a new enclosure for solar connectors to prevent fire risks in PV systems.

Faulty connectors are among the most frequent causes of fires in rooftop solar arrays. One problem is cross-mating, which happens when connectors of different kinds are mated.

Viridian Solar said its ArcBox enclosure can be easily snapped around the outside of an MC4 electrical connector.

“Testing by Loughborough University and the KIWA fire test laboratories has confirmed that ArcBox safely contains a DC arc within the connector and prevents it from spreading to start a fire in nearby combustible materials,” it said. “The patented product also provides sufficient ventilation for the connector to remain within permitted temperature limits in normal use.”

It said that the use of connectors from different manufacturers has prompted regulators in many countries to prohibit cross-mating of different connectors. However, it is still difficult for installers to identify connectors from different suppliers.

Viridian Solar recommends the product for building-integrated photovoltaic (BIPV) projects. “We also see a requirement for ArcBox for above-roof solar systems installed over combustible roof coverings such as asphalt and single ply membrane and for solar on buildings that if put out of use, even for a short period, would have significant knock-on effects – such as hospitals, care homes, schools or factories,” it said.