What Are The Standards For Cable Tray Installation?
Cable tray manufacturers in India have to follow the standards set by NEMA that define the types of environments for electrical enclosures.
What does NEMA stand for?
NEMA stands for the National Electrical Manufacturers Association. The NEMA standard VE2 specifies cable tray installation procedures, material management, and unloading/storage requirements.
Although cable trays are an important component of the wiring systems, if they are not designed and installed properly, they can pose potential dangers, such as fire, electric shock and arc-flash blast events.
The following problems should be considered during the maintenance, installation, and inspection of cable trays :
- A NRTL must specify or label cable trays, as well as the conductors and cables they contain, as acceptable for the area in which they are installed.
- To prevent the spread of a fire or combustion by-products, adequate fire stops should be provided where cable trays pass through fire-rated partitions, walls, and floors, in accordance with NEC Section 300.21.
- In hazardous locations, cable trays must contain only the wiring that is allowed there.
- According to the installation directions, cable trays must be appropriately supported.
- Overloading cable trays can cause the tray, its connection points, and/or supports to fail, posing a risk to those underneath the tray. It can potentially result in electric shock and arc-flash/blast events due to component failure when the cables are suddenly no longer supported.
- In overfilled cable trays, excessive heat can build up around live conductors and cause the insulation to break down, posing shock hazards and causing fires.
- The 2005 NEC specifies fill values for cable trays that vary from a single layer to nearly a 50% fill of the cross-sectional area of the cable tray.
- In cases in which cable trays are overfilled beyond the fill criteria established by NEC, add another cable tray system above, below or next to the overfilled tray. Provide enough working space around the added cable tray when overfilled trays exceed the NEC fill criteria.
- For personal safety as well as protection against arcing, grounding cable tray systems is critical which can occur anywhere in the wiring system. Before cables are placed or activated, they must be properly grounded and checked.
- Cable trays containing unused cables should be removed.
- Employees working on cable tray installations may come into contact with live parts. Deenergization of live parts to which an employee may be exposed is necessary before employees begin work on or near them, according to 29 CFR 1910.333(a)(1).
Cable tray manufacturers in India have responded to the above stated problems by establishing their product as the safest mode of cable management.
Cable Tray Installation Standards
Cable tray manufacturers in India are liable to follow the following installation standards
- The National Electrical Code (NEC®) guidebook, section 392, contains instructions and specifications for installation of the cable tray. It states that the cable tray must be installed as a complete system.
- Field bends or adjustments must be done in such a way that the cable tray system’s electrical continuity and cable support is properly maintained. Mechanically discontinuous segments between cable tray runs or between cable tray runs and equipment are permissible in cable tray systems.
- The system as a whole should provide a secure, safe, and reliable manner of storing cables and wires. To do so, the designer must choose a cable tray that is structurally sound for their installation. The strength of the cable tray, the cable tray loading, and the spacing of the supports all factor into this decision.
- According to the (NEC®), the most important aspect of the installation is to ensure that the metallic cable tray system has electrical continuity all through the length and that the cables are supported.
- Even if there are installation scenarios where the cable tray is mechanically discontinuous, such as with a firewall penetration, an expansion gap in some kind of a long straight cable tray run, a change in elevation of a few feet between two horizontal cable tray sections of the same run, as well as where cables descend from an overhead cable tray to enter equipment, these requirements should be adequately met.
Installation Codes :
- NFPA 70 – The National Electrical Code specifies the installation standards for cable tray systems such as ladders, ventilated troughs, vented channels, solid bottoms, and similar structures.
- Article 392 specifies “Uses Permitted,” including “Cross Sectional Area Requirements for Cable Trays Used as Equipment Grounding Conductors” and “Maximum Allowable Fill Area for Single-Conductor and Multi-Conductor Cables. The conductors’ capacities are defined in Article 310.
- CEC C22.1-Part 1 – The Canadian Electrical Code is a safety standard that governs the installation and maintenance of electrical equipment across the country. “Method of Installation,” “Ampacities of Conductors,” and “Conductors in Cable Trays” are all covered by Section 12-2200.
- NFPA 79 – This standard addresses the safe use of electric/electronic equipment, apparatus, or systems that are supplied as part of industrial machinery or mass-produced industrial equipment.
- NFPA 70E – This standard addresses personnel protection from electrical hazards such as shock, arc blasts, and explosions.
Pinax Steel is a reputed name when it comes to steel products in India. We provide complete cable tray solutions from our state-of-the-art facility in Patna. We manufacture customised, high-quality and durable cable trays for you.
As cable tray manufacturer in India, we offer cable trays in various shapes and sizes such as :
We also provide several options when it comes to finishes: