Cable Tray Systems
Cable tray systems are an assembly of sections or units forming a rigid structural system used to securely fasten or support cables or raceways. They are used as an alternative to open wiring and electrical conduit systems in commercial and industrial applications. They are especially useful in situations where changes in wiring systems are expected, since new wires and cables can be installed by laying them in the tray, rather than pulling them through conduit. Several types of cable trays are used in different applications.
Solid-bottom cable trays provide continuous support for cables, but require fittings or cutting in order to insert or remove cables. A solid enclosure for cables is a cable trough or cable channel.
Ventilated cable trays have openings in the bottom to allow air circulation, as well as water drainage. Small wires and cables may exit the tray through the ventilation openings. Some ventilated cable trays have solid covers to protect cables from falling dust, debris and water.
Wire mesh or basket cable trays are used to route and support small cables and wires. The mesh is smooth to prevent cutting and abrasion to the cable during installation and allows air to flow through the tray. Wire mesh trays can be bent or cut in configurations to accommodate complex cable runs and can be mounted on walls, overhead or under floors.
4 best practices when fabricating a control panel.
- Use a larger enclosure whenever possible. This allows room in the panel design to properly space all of the hardware and to install larger wire ducting. Panels that have ample space tend be me more organized, while panels that have everything crammed into a small space tend to be more difficult to work in and are often less organized.
- Tap holes instead of using self-tapping screws. It is common for panel builders to use self-tapping screws to save time during the fabrication process. While it can save time, this type of fastener does not always provide the consistent, strong connection that may be needed for the mounted hardware. This is especially true when hardware may need to be removed at some point and then later reattached. Holes that have been tapped prior to hardware installation will offer a stronger, more consistent connection point that will last longer.
- Ensure that wire ducting is large enough. It is very easy to undersize wire ducting when designing a panel. It is important to always plan for wire ducting to have extra room available once all wires have been run through it, including field wires.
- When in doubt, label it. It is a very good practice to label wires in a control panel, but it is not always required to label the other types of hardware in the panel to meet code. It is important to understand that any operators that may access this panel at a later date may not understand what the hardware in the panel is intended for. To make the panel is as safe as possible, and to allow operators to function in the panel more efficiently, it is a good idea to label everything that may come into question.