Tray Installation, NSL Noise Susceptibility Level
Tray Installation:
Cable Tray Installation:
- The publication is intended as practical guide for the proper installation of cable system.
- Cable tray systems design and Installation shall comply with NEC Article – 392 & 318,
- NEMA VE1, NEME VE2 and NEMA FG 1 and follow safe practices as described in NFPA 70E.
Tips for Cable Tray Installation:
– Cable tray specification shall be per NEMA VE1 the tray shall be per NEMA VE2.
– The distance between consecutive rungs shall not exceed 229 mm (9 Inch).
– Cable Ties for Vertical Application shall be provided every 18 inch (after one rung).
– Cable Tied for Horizontal application shall be provided every 27 inch (after two rungs).
– Unless otherwise noted, the support interval shall be not more than 2.4 meters as per NEMA VE1.
– For the Vertical Application cable ties must be 316SS with PVC coated.
– The open gap between tray/conduit to the instrument maximum 350 mm.
– The cable tray system shall be installation with manufactures standards fittings.
– Such as Clamps, Splicer Plates, Connector, Hangers, Reducer Plates, Grounding Brackets Blind, Nut Bolts, Washers etc.
– The channel cable tray material shall be copper free aluminum (Aluminum with max of 0.4% copper).
– Channel cable tray width shall be 3, 4, or 6 inches with a minimum loading depth of 1 ¼ inch.
– Non metallic cable tray permitted in corrosive area. Non metallic cable trays shall be made of flame retardant material.
NSL: Noise Susceptibility Level
Level 1: High to
Medium susceptibility analog signals of less than 50V and discrete instrument
signal of less than 30V.
Level 2: Low susceptibility switching signal greater
than 30V, analog signals grater then 50 V and 120 ~ 240 AC feeder less than 20
Amps.
Level 3: Power AC and DC buses of 0 ~ 1000 V with
currents of 20 ~ 800 Amps.
Tray to Tray Spacing in mm:
- NSL 1 2 3
- 1 0 150 650
Tray to Conduit Spacing in mm:
- NSL 1 2 3
- 1 0 100 450
Conduit to Conduit Spacing in mm:
- NSL 1 2 3
- 1 0 75 300
Tray to Tray:
- Level 1 to Level 2 gap should be 150 mm
- Level 2 to Level 3 gap should be 500 mm
- Level 1 to Level 3 gap should be 650 mm
Tray to Conduits:
- Level 1 to Level 2 gap should be 100 mm
- Level 2 to Level 3 gap should be 350 mm
- Level 1 to Level 3 gap should be 450 mm
Conduit to Conduit:
- Level 1 to Level 2 gap should be 75 mm
- Level 2 to Level 3 gap should be 225 mm
- Level 1 to Level 3 gap should be 300 mm
