312 – Cabinets, Cutout Boxes, and Meter Socket Enclosure

312.8(B) – Energy Management Equipment

Change at a Glance:

The term “Energy Management Equipment” added to equipment permitted within the wiring space of enclosures for switches or overcurrent devices along with power monitoring equipment. A new list Item (3) was added for conductors used exclusively for control or instrumentation circuits.

312.8 Switch and Overcurrent Device Enclosures.

(B) Power Monitoring or Energy Management Equipment. The wiring space of enclosures for switches or overcurrent devices shall be permitted to contain power monitoring or energy management equipment where all of the following conditions are met: in accordance with 312.8(B)(1) through (B)(3).
(1) Identification. The power monitoring or energy management equipment is shall be identified as a a field installable accessory as part of the listed equipment, or is a listed kit evaluated for field installation in switch or overcurrent device enclosures.
(2) Area. The total area of all conductors, splices, taps, and equipment at any cross section of the wiring space does shall not exceed 75 percent of the cross-sectional area of that space.
(3) Conductors. Conductors used exclusively for control or instrumentation circuits shall comply with either 312.8(B)(3)(a) or (B)(3)(b). (a) Conductors shall comply with 725.49. (b) Conductors smaller than 18 AWG, but not smaller than 22 AWG for a single conductor and 26 AWG for a multiconductor cable, shall be permitted to be used where the conductors and cable assemblies meet all of the following conditions:
(1) Are enclosed within raceways or routed along one or more walls of the enclosure and secured at intervals that do not exceed 250 mm (10 in.)
(2) Are secured within 250 mm (10 in.) of terminations
(3) Are secured to prevent contact with current carrying components within the enclosure
(4) Are rated for the system voltage and not less than 600 volts
(5) Have a minimum insulation temperature rating of 90°C