UL 209:2020 pdf download.Cellular Metal Floor Raceways and Fittings.
5.2 Both the inside and outside surfaces of header duct or trench headers shall be protected against corrosion, If zinc is used, the coating shall comply with the requirements in Protective Coating — Zinc, Section 14, If a metal other than zinc or if a nonmetallic material is used, the corrosion protection afforded by the coating shall not be less than that of the specified zinc coating. If enamel is used, the coating, at any time up to one year from the time of manufacture, shall comply with the requirements in Protective Coating
— Enamel, Section 15.
6 Cellular Metal Floor Raceways
6.1 A cellular floor unit shall be made of sheet steel,
6.2 No element shall be thinner than 0.034 inch (0.86 mm) when measured alter Fabrication but, If the upper element is thinner than 0.056 inch (1 42 mm). the following restrictions apply to the unit:
a) If the upper element is thinner than 0.056 inch (1,42 mm), the installation instructions mentioned in 19,1 shall specify that the upper element is to be protected by at least 1 inch (25 mm) of concrete:
b) If the upper element is thinner than 0.045 inch (1.14 mm), it shall be strengthened so that a representative sample of the complete unit complies with the Load Test, Section 10. The cell width and cross-sectional area need not be specified;
C) If the upper element is thinner than 0.045 inch (1.14 mm) and is not strengthened so that a representative sample of the complete unit complies with the Load Test, Section jQ. no ce shall be wider than 4 inches (102 mm) or larger in cross-sectional area than 10 inches2 (64.5 cm2).
6.3 The thicknesses of 0.034 — 0,056 inch (086 — 142 mm) that are mentioned in 6,2 are the minimum values for cellular floor units as raceways for electrical wiring. Units employing heavier steel are needed and are regularly furnished where greater mechanical strength is essential for structural purposes. These units shall be subjected to the Load Test, Section 10.
6.4 The upper and lower elements of the cellular floor units shall be fastened by spot welds or other fastenings of sufficient quantity to give the finished unit strength for the conditions of use. Spot welds shall comply with the Tension/Shear Test, Section and Peel Test. Section 12.
6.5 The following shall be constructed of zinc-coated sheet steel of the same thickness as the upper element of the unit (see 6.2 and 63 for the specific thickness).
— Enamel, Section 15.
6 Cellular Metal Floor Raceways
6.1 A cellular floor unit shall be made of sheet steel,
6.2 No element shall be thinner than 0.034 inch (0.86 mm) when measured alter Fabrication but, If the upper element is thinner than 0.056 inch (1 42 mm). the following restrictions apply to the unit:
a) If the upper element is thinner than 0.056 inch (1,42 mm), the installation instructions mentioned in 19,1 shall specify that the upper element is to be protected by at least 1 inch (25 mm) of concrete:
b) If the upper element is thinner than 0.045 inch (1.14 mm), it shall be strengthened so that a representative sample of the complete unit complies with the Load Test, Section 10. The cell width and cross-sectional area need not be specified;
C) If the upper element is thinner than 0.045 inch (1.14 mm) and is not strengthened so that a representative sample of the complete unit complies with the Load Test, Section jQ. no ce shall be wider than 4 inches (102 mm) or larger in cross-sectional area than 10 inches2 (64.5 cm2).
6.3 The thicknesses of 0.034 — 0,056 inch (086 — 142 mm) that are mentioned in 6,2 are the minimum values for cellular floor units as raceways for electrical wiring. Units employing heavier steel are needed and are regularly furnished where greater mechanical strength is essential for structural purposes. These units shall be subjected to the Load Test, Section 10.
6.4 The upper and lower elements of the cellular floor units shall be fastened by spot welds or other fastenings of sufficient quantity to give the finished unit strength for the conditions of use. Spot welds shall comply with the Tension/Shear Test, Section and Peel Test. Section 12.
6.5 The following shall be constructed of zinc-coated sheet steel of the same thickness as the upper element of the unit (see 6.2 and 63 for the specific thickness).
