CSLB C-46 Solar ContractorPhotovoltaic System InstallationMedium
A solar technician is inspecting the electrical connections of a PV array after a strong wind storm. They notice several loose connections at MC4 connectors. What is the most likely electrical hazard that could result from these loose connections?
- AOvervoltage
- BReverse polarity
- CGround fault
- DArc fault
Show answer & explanationAnswer & explanation
Correct answer: D. Arc fault
Loose electrical connections, especially in DC circuits like those found in PV arrays, can create resistance. When current flows through this resistance, it can generate heat and cause an electrical arc (spark). This 'arc fault' is a significant fire hazard and can damage equipment.
Why the other options are wrong
- A. Overvoltage is typically caused by system design issues or lightning, not loose connections.
- B. Reverse polarity is a wiring error, not a result of loose connections after installation.
- C. A ground fault occurs when current flows to ground through an unintended path, not directly from loose connections.
DC Arc Faults
An unintended electrical discharge (spark) that occurs in a DC circuit, often caused by loose connections, damaged insulation, or compromised conductors.
- Significant fire hazard.
- Commonly caused by loose connections or damaged wiring.
- PV systems require arc-fault circuit interrupters (AFCI) for detection.
Memory trick: Loose connections spark trouble, arcs are the main peril.