FIXED ELECTRIC SPACE HEATING EQUIPMENT 70-373

(4) The manufacturers of heating panels or heating panel sets shall provide marking labels that indicate that the space heating installation incorporates heating panels or heating panel sets and instructions that the labels shall be affixed to the panelboards to identify which branch circuits supply the circuits to those space heating installations. Exception: Heating panels and heating panel set installations that are visible and distinguishable after installation shall not be required to have labels provided. 424-93. Installation. (a) General. (1) Heating panels and heating panel sets shall be installed in accordance with the manufacturer's instructions. (2) The heating portion shall not: a. Be installed in or behind surfaces where subject to physical damage. b. Be run through or above walls, partitions, cupboards, or similar portions of structures that extend to the ceiling. c. Be run in or through thermal insulation, but shall be permitted to be in contact with the surface of thermal insulation. (3) Edges of panels and panel sets shall be separated by not less than 8 inches (203 mm) from the edges of any outlet boxes and junction boxes that are to be used for mounting surface lighting fixtures. A clearance of not less than 2 inches (50.8 mm) shall be provided from recessed fixtures and their trims, ventilating openings, and other such openings in room surfaces. Sufficient area shall be provided to assure that no heating panel or heating panel set is to be covered by any surface-mounted units. Exception: Heating panels and panel sets listed and marked for lesser clearances shall be permitted to be installed at the marked clearances. (4) After the heating panels or heating panel sets are installed and inspected, it shall be permitted to install a surface that has been identified by the manufacturer's instructions as being suitable for the installation. The surface shall be secured so that the nails or other fastenings do not pierce the heating panels or heating panel sets. (5) Surfaces permitted by Section 424-93(a)(4) shall be permitted to be covered with paint, wallpaper, or other approved surfaces identified in the manufacturer's instructions as being suitable. (b) Heating Panel Sets. (1) Heating panel sets shall be permitted to be secured to the lower face of joists or mounted in between joists, headers, or nailing strips. (2) Heating panel sets shall be installed parallel to joists or nailing strips. (3) Nailing or stapling of heating panel sets shall be done only through the unheated portions provided for this purpose. Heating panel sets shall not be cut through or nailed through any point closer than ¼ inch (6.35 mm) to the element. Nails, staples, or other fasteners shall not be used where they penetrate current-carrying parts. 70-374 NATIONAL ELECTRICAL CODE (4) Heating panel sets shall be installed as complete units unless identified as suitable for field cutting in an approved manner. 424-94. Clearances of Wiring in Ceilings. Wiring located above heated ceilings shall be spaced not less than 2 inches (50.8 mm) above the heated ceiling and shall be considered as operating at an ambient of 50°C (122°F). The ampacity shall be computed on the basis of the correction factors given in the 0-2000 volt ampacity tables of Article 310. Exception: Wiring above heated ceilings and located above thermal insulations having a minimum thickness of 2 inches (50.8 mm) shall not require correction for temperature. 424-95. Location of Branch-Circuit and Feeder Wiring in Walls. (a) Exterior Walls. Wiring methods shall comply with Article 300 and