Outdoor distribution boxes must be protected against lightning strikes

Type 1 SPDs should be installed at the service entrance, while Type 2 SPDs provide protection at distribution levels. Modern ACDB boxes should incorporate built-in surge protection. We reserve the right to make changes in design, technology, dimensions, weights and materials in the course of technical progress. We accept no liability for misprints, modifications and errors. Openings around boxes in noncombustible surfaces must not exceed ¼ inch to prevent fire spread. For systems located in high lightning regions, the neutral is also grounded where line arresters are installed. This guide breaks down everything homeowners need to know about. [pdf]