ANSI/NEIS 105:2007 pdf download.Installing Metal Cable Tray Systems.
4.5.4 FInish Touch Up
Cable trays that have a hot dip galvanized coating applied after fabrication need to be retouched after culling, drilling, or debumng or if the coating gets damaged. These cutting operations leave bare metal edges that will begin to corrode immediately. Cable trays made from mill galvanized steel do not need to be touched up because they are not designed to be used in heavily corrosive atmospheres and have bare metal edges inherent in their design. Aluminum cable trays do not need to be touched up.
Touch up of the galvanized finish must be done according to ASTM A 780. Repair of Damaged Hot.Dip Gajvan,zed Coabngs. Use an approved zinc-rich galvanizing material that meets the requirements of ASTM A 780. If it is not noted on the product label as to whether the material meets ASTM A 780, the material specification sheet should be obtained from the galvanizing material supplier. The paint can be applied by bwstling or spraying. Always paint 13mm (1t2 in.) to 25mm (1 in.) beyond the bare area to prevent undercutting by corrosion.
After cutting of flbecglass cable trays, seal cut edges with manufacturer’s recommended sealant.
Other protective coatings that are cut or damaged must b€ touched up with compatible coatings.
4.5.5 Wire Mesh Fittings Fabrication
Fittings are field fabricated Irom straight sections on-site with an offset bolt cutter and wrench, or high speed grinder.
Horizontal or vertical bends, tees, and crosses are fabricated by notching out segments of side rail grids and overlapping and connecting parallel wires by means of a connector.
4.7 GROUNDING AND BONDING
Metal cable trays must be grounded and electrically continuous systems per NEC Article 392.7 For specific areas requiring bonding for electrical continuity, refer to Figures 4.57 through 4.60.
NOTE—Non-nw cabl, trays do not serve a a cudor
NOTE—It is reconneided that wire mesh cable trays not be used as Si equipment rounding conductor.
NOTE—Ajtliough permitted by the NEC, it It reconwnended due to tie urique nature at tie wire mesh, rittings are manuFactured in the reid From straight aectais by cutting away ew current carrying structural wires. reducing tie cwrent-cavig capebittty ot tie aysieni. As such, tie use of sire mea?i cable trays as an equipment grounding conductor Is not recommended- if the wee mesh cable tray Is to be used a an equipment oun&ug conductor, then the instalLatIon ola grand wire is recommended (a wire mesh cable tray a si4portrig cable with a built-In equipment grounding conductor or control or egnat cables, then the tray should have a low impedance peth to a non-system ground to reduce nase and remove induced or stray currents, A separate oundmg cable attached to tie ewe mesh cat$e tray a not usually required.
4.7.1 Cable Tray Used as an Equipment Ground Conductor (EGC) (See Figures 4.57 through 4.60) The use of aluminum and steel cable trays is permitted as an Equipment Grounding Conductor per NEC Article 392 when labeled and marked with the available cross sectional area. (See Table 4-4.) If the cable tray Is to be used as an EGC. bonding jumpers must be installed on both side rails at the locations illustrated in Figures 4.57 through 4.60. unless the splice plates meet the electrical continuity requirements of NEMA VE 1, See Table 4-5 for minimum sizes of grounding conductors.
If the connectors are UL Classified bonding jumpers or a continuous ground are not required.
It Is not necessary to install bonding jumpers at standard rigid aluminum or galvantzed steel splice plate connections or offset reducing splice plate connections or any UL Classified connectors.
For rigid splice plate connections of materials and finishes other than aluminum or galvanized steel, bonding jumpers may be required. For example, stainless steel splice plates may require bonding umpers depending UL Classification.
