What must be done with unused openings on service equipment?

Unused openings on service equipment must be properly sealed to prevent the entry of moisture, dirt, and contaminants that could compromise the functionality and safety of the electrical system. Proper sealing helps maintain the integrity of the equipment, ensuring that it operates reliably and reduces the risk of electrical faults or hazards.

Sealing unused openings also protects against insects and other pests, which could cause further issues within the service equipment. According to the National Electrical Code, it is crucial that all unused openings be closed unless there is a specified requirement for ventilation.

In contrast, ignoring these openings could lead to potential safety hazards. Leaving them open for ventilation is generally not permissible in most situations, as this could allow moisture and debris to enter, posing risks. Additionally, while it's important to follow established protocols for all sizes of openings, the requirement to seal applies universally—not just to large ones.

Overall, sealing unused openings is critical for ensuring the ongoing safety and performance of electrical service equipment as outlined in the NEC guidelines.