1. The National Electrical Code publishes the standards for all types of electrical applications. Articles 318, 250, and 800 cover various aspects of cable tray systems.
2. NEMA, (National Electrical Manufacturers Association), is an association comprised of the major cable tray manufacturers in the industry. This committee has published three documents to date: NEMA VE1, FG1 and VE2.
NEMA VE1 covers general cable tray definitions, manufacturing standards, performance standards, test standards, and application information.
NEMA FG1 addresses the standards for fiberglass cable tray systems.
NEMA VE2 is a cable tray installation guideline which covers receiving and unloading material, storage of material, and general installation practices.
Power Cables – No. of Cores 2,3, 3 1/2 & 4 Core
Control Cables – Upto 63 Cores or above Standards Applicable for both – IS-694 & IS-1554 .
Unsheathed – Only Core Insulation will be done and there will be no Sheathing.
Sheathed – Sheathing will be done on Core Insulation.
Control Cables – They are generally Core Constructed.
Instrumentation Cables – They are generally Pair Constructed with Shielding.
Conductor Material is different for both.
This type of cable is used for Very High Frequency (V.H.F.) Applications.
Low Voltage Grade — upto and including 1.1 KV
High Voltage Grade — above 1.1 KV
a. Incase of 7 Strands – 7/0.52
b. Incase of 0.3 mm dia each – 21 Strands
c. Incase of 0.2 mm dia each – 48 Strands.
By Colour or By Number printed Al-Mylar Tape / Polyster Tape.
To reduce the interference by nearby sources.
a. Al-Mylar / Cu-Mylar Tape
b. ATC or ABC Braiding.
a. Core Insulation – 0.2, 0.3 mm
b. Sheath – 0.5 to 1.2 mm.
RTD Cables will be Triad Constructed.
Instrumentation Cables are Pair constructed.
1.5 & 2.5 Sq.mm
0.5, 0.75, 1.0, 1.5 & 2.5 Sq.mm
a. Single pair – 16 AWG (1.295 mm dia)
b. Multi pair – 20 AWG (0.813 mm dia)
a. IS 8784 +/- 3 Deg. C
b. ANSI MC 96.1 +/- 2.2 Deg. C
a. Upto 5 Cores by different colours i.e for 2 Cores Red & Black, for 3 Cores Red, Yellow & Blue, for 4 cores Red, Yellow, Blue & Black, for 5 Cores Red, Yellow, Blue, Black & Grey.
b. Above 5 Cores : One Core Yellow and One Core Blue remaining Grey in each layer (or) any single colour with numbers printed.
For above 5 Cores Grey with number printing is our normal practice.
a. Annealed Tinned Copper Braided Cables
b. Annealed Bare Copper Braided Cables
c. Nickle Plated Copper Braided cables
d. G.I. Braided Cables.
PTFE – 250 Deg.C, FG Cables 400 Deg.C