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