Improperly secured covers on outdoor cable trays can cause a serious safety hazard in high winds. In the majority of cases, covers are not used on cable trays for technical or safety reasons, but due to the “raceway complex,” a feeling by specifiers[……]
Category Archives: Technical Articles
Circuit Integrity of Cable Tray Wiring Systems During Natural Disasters
The January 17,1994 Los Angles, California earthquake and the hurricanes of past years emphasize that the design and installation of structures and systems that may be subjected to these types of natural disasters should be such that the damage is ke[……]
Tie Down Practices for Multiconductor Cables in Cable Trays (note single conductor practices are to covered in a new bulletin)
There are three items which require decisions concerning the tying down of multiconductor cables in cable tray wiring systems. Item #1 is to define under what conditions the multiconductor cables in cable trays are to be tied down. Item #2 is to defi[……]
Cable Tray Type Selection
What type of cable tray should be used for the main runs of a cable tray wiring system? The cable tray types to choose from are ladder, ventilated trough, or solid bottom. What are the reasons for selecting a specific type of cable tray?
The engin[……]
Moisture Problems in Electrical Systems
When selecting a facilities wiring system, the potential for the wiring system to allow moisture to flow into the electrical equipment enclosures should be evaluated. This is true for all wiring requirements: electrical power, instrumentation data, c[……]
Thermal Contraction and Expansion of Cable Tray
All materials expand and contract due to temperature changes. It is important that cable tray installations incorporate features which provide adequate compensation for their thermal contraction and expansion.
1993 NEC Section 300-7 (b) states tha[……]
Paralleled Phase Conductors in Cable Trays Provide Copper Savings
Cable tray wiring systems have conductor advantages over conduit wiring systems where the installations involve phase conductors installed in parallel.
For large ampacity circuits, the most practical wiring system installations are those where rea[……]