UL 467-2017 pdf download – Grounding and Bonding Equipment.
6.3 Strap-type clamps 6.3.1 A strap-type clamp shall not be less than 1 2.7 mm (1 /2 in) wide and 0.64 mm (0.025 in) thick. 6.3.2 A communications strap-type clamp shall not be less than 1 2.7 mm (1 /2 in) in width and not be less than 0.64 mm (0.025 in) in thickness. Strap-type clamps intended for outdoor use shall satisfy the temperature conditioning test described in Clause 9.9. 6.3.3 Communication ground clamps may be in the form of straps of copper or other suitable meta l. 6.3 .4 Communication ground straps fitted either with brass or galvanized steel screws. 6.4 Protection against corrosion 6.4.1 A grounding or bonding device shall be protected by a zinc coating at least 0.025 mm (0.001 in) thick , except as follows: a) if the metal is inherently resistant to corrosion such as nonferrous or stainless steel; b) a device that is used in conjunction with an electrical metallic raceway or metallic cable system and complies with the corrosion protection requirements for fittings in CSA C22.2 No. 1 8.3 or UL 51 48; c) the thickness of the coating shall be at least 0.01 3 mm (0 .0005 in) if the device provides for a direct pressure connection between the grounding or bonding conductor and the surface of an outlet box; d) the thickness of the coating shall be at least 0.0038 mm (0 .0001 5 in) if the device is intended for use completely inside an outlet box. Also see Clause 6 .4 .6. 6.4.2 In regards to Clause 6.4.1 , corrosion protection on small of the grounding and bonding device , such as screws , is not specified. Evidence of corrosion protection shall be verified by visual inspection. 6 .4 .3 Unless a grounding or bonding device is made of a material specified in Clause 6.1 .2 , a plating or a coating provided on the device shall not be of a material or color that would tend to indicate that the device is of a material other than that of which it is actually made. 6 .4.4 Except as specified in Clause 6 .4 .3 , colored chromate shall be permitted.
6 .4 .6 In accordance with Clause 6 .4 .1 , a device constructed of ferrous metal shall be protected against corrosion by one of the following means or by other metallic coatings that have been found to give equivalent protection , as described in Clause 6.4.7: a) hot-dipped , mill-galvanized sheet steel conforming with the coating designation G90 in Table 1 of ASTM A 653/A 653M , with not less than 40% of the zinc on any side , based on the minimum single-spot-test requirement in ASTM A 653/A 653M. The weight of zinc coating may be determined by any acceptable method; however , in case of question , the weight of coating shall be established in accordance with ASTM A 90/A 90M; and b) a zinc coating , other than that provided on hot-dipped mill-galvanized sheet steel , uniformly applied to a thickness of not less than 0.025 mm (0.001 in) on each surface. The thickness of the coating shall be established by the thickness of protective coating test described in Clause 9.6. 6 .4 .7 With reference to Clause 6.4.6 , other finishes , inciuding special metallic finishes , may be used when comparative tests with galvanized sheet steel having no annealing , wiping , or other surface treatment that conform to Clause 6 .4 .6 , It em indicate they provide equivalent protection. Note: Among the factors that are taken into consideration when judging the acceptability of such coating systems are exposure to salt spray , moist dioxide-sulphur dioxide-air mixtures , moist hydrogen sulphide -air mixtures , ultraviolet light , and water. 6.5 Ground clamps 6.5.1 Clamps and electrode connections shall be any one of the following: a) rigid bolted clamps of cast , formed , or extruded metal; b) plug-type grounding fittings (pipe fittings , plugs , or other approved forms for threading into pipes or pipe fittings); or c) exothermically welded connections.