What is the instrument Tray layout?
The Instrument Tray Layout is the diagram that indicates the location of the junction boxes, instrument air header, local panel, and instrument tray routing with respect to the Instrument location layout.
Detailed Explanation of Instrument Tray Layout
Cable Tray wiring systems are more common than conduit wiring systems because they are safer, more reliable, take up less space, and are cheaper.
Instrument Tray Layout is the drawing that shows where the junction boxes, instrument air header, local panel, and instrument tray routing are in plan view.
They are created using the Instrument Location Layout specifications, which assists in grouping junction boxes and air headers.
In cross-sectional orientation, they also indicate the elevation and the quantity of trays running in tiers.
Instrument Tray Layouts are generally designed to display all instruments and instrument-related things that are located in the field and connected to the control room through multicore cables usually run on instrument trays.
Who can use the Instrument Tray layout?
Instrument tray layouts are used by a variety of personnel in the design, installation, operation, and maintenance of process control systems. These may include:
Engineers: Engineers may use instrument tray layouts to design and specify the control system, including the type and number of instrument cables required, and their locations on the tray.
Technicians: Technicians may use instrument tray layouts to lay the instrument cables on the tray that can be used to wire the instruments and control devices, following the instructions provided in the layout.
Maintenance personnel: Maintenance personnel may use instrument tray layouts to troubleshoot and maintain the control system, by identifying the instrument cables laid on the tray.
Overall, instrument tray layouts are an important tool for anyone involved in the design, installation, operation, and maintenance of process control systems cables.
Instrument Tray Dimensions:
The dimensions of an instrument tray will depend on the specific requirements of the process control system and the facility in which it is being used. The size of the tray will be determined by the number and type of instrument cables that need to be mounted on it, as well as the physical space available for the tray within the facility.
In general, instrument trays are designed to be as compact as possible, while still allowing sufficient space for the instrument cables to be properly laid and accessed. The tray dimensions may be determined using a combination of standard sizes and custom sizing, based on the needs of the control system and the constraints of the facility.
Some common dimensions for instrument trays are:
600 mm x 600 mm (24 in x 24 in)
600 mm x 900 mm (24 in x 36 in)
600 mm x 1200 mm (24 in x 48 in)
These dimensions may vary depending on the specific requirements of the control system and the facility in which it is being used.
A drawing of a cable tray layout is shown below.
Nomenclature
- Ladder type cable tray
- Ventilated trough type cable tray
- Splice plate
- 90-degree horizontal bend, ladder type tray
- 45-degree horizontal bend, ladder type tray
- Horizontal tee, Ladder type tray
- Horizontal cross, ladder type tray
- 90-degree vertical outside bend, ladder type tray
- 45-degree vertical outside bend, ladder type tray
- 30-degree vertical inside bend, ladder type tray
- Vertical bend segment (VBS)
- Vertical tee down, vertical trough type tray
- Left hand reducer, ladder type tray
- Frame type box connector
- Barrier strip straight section
- Solid flanged tray cover
- Cable channel straight section, ventilated
- Cable channel, 90-degree vertical outside bend
