CSLB C-46 Solar ContractorPhotovoltaic System InstallationMedium
A solar technician is inspecting the electrical connections of a PV array after a strong windstorm. They notice several loose DC connectors on the roof. What is the most significant electrical hazard associated with loose DC connections in a PV system?
- AAccelerated degradation of PV module insulation.
- BReduced system efficiency due to increased resistance.
- CInverter shutdown due to low voltage.
- DDC arc faults, posing a fire risk.
Show answer & explanationAnswer & explanation
Correct answer: D. DC arc faults, posing a fire risk.
Loose or improperly seated DC electrical connections in a PV system are a primary cause of DC arc faults. When current flows through a poor connection, it can create a localized high-resistance point, generating intense heat and plasma, leading to a sustained electrical arc that poses a serious fire hazard. While other issues might occur, fire risk from arc faults is the most significant hazard.
Why the other options are wrong
- A. While prolonged heat could eventually affect insulation, direct arc faults are a more immediate and severe hazard.
- B. Reduced efficiency is a consequence, but not the most significant hazard.
- C. Low voltage might occur, but it's not the primary hazard compared to an arc fault.
DC Arc Faults
An unintended electrical discharge that occurs in a DC circuit, often caused by loose connections, damaged insulation, or compromised conductors.
- Can generate extremely high temperatures (up to 10,000°F).
- Major fire hazard in PV systems.
- Arc-Fault Circuit Interrupters (AFCI) are required to detect and mitigate them.
Memory trick: Loose wires spark a fire's desire, setting the roof higher and higher!