All electrical equipment and wiring in the wetwell shall comply with the applicable provisions of National Electrical Code (NEC) Article 501 for Class I, Division 2 locations.

A weatherproof (NEMA 4X) stainless steel junction box for each pump unit, with the bottom mounted no less than three feet above grade, shall be the enclosure used for terminating the power and signal cables.

These junction boxes along with other required junction boxes shall be placed at locations accessible in close proximity to the access hatch of the vault.

The conduit run containing electrical cables for control and motor leads between the wetwell and junction box shall include a Class I, Division 2 explosion-proof seal.

The valve vault will be considered to be an unclassified area if continuously ventilated at a minimum of six air changes per hour.

All conduits underground, with the exception of the wetwell, shall be Schedule 80 PVC. Conduits run exposed in the valve vault shall be Schedule 80 PVC. Conduits run within the wetwell shall be PVC-coated rigid galvanized steel. Minimum conduit size shall be three-quarter inches. Provide a minimum of one-quarter-inch standoff support for mounting on concrete and masonry surfaces.

Conductors shall be copper. Conductors No. 12 AWG and No. 10 AWG shall be solid and No. 8 AWG and larger shall be stranded.

All equipment on concrete and masonry walls shall be mounted off the wall providing a minimum of one-quarter-inch air space using a unistrut or similar mounting system.

Warning tape with metallic lining shall be installed over all underground conduit runs. (Design Guideline DG-08 § 13.6, dated August 2006)