Tips for Cable Tray Installation NSL Noise Susceptibility Level - QC Notes

 

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.

Splice Plate

Expansion Plate

Pull Box

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