In the case of a solid conductor such as copper wire, the electrical resistance is proportional to the length of the conductor and inversely proportional to its cross-sectional area. In effect this means that the longer a piece of wire, the higher its resistance. Similarly the greater the dia...
The elements to consider are: The size/rating of the service entrance conductors. The rating of the panel. The rating of the main breaker, if any. The rating of the meter base. The rating of the meter. The weakest or smallest of these five items will determine the service ampacity of ...
Consult ampacity tables to determine appropriate widths based on temperature rise, copper weight, and other factors. When in doubt, go thicker. Distribute Across Layers Use multiple board layers with entire planes dedicated to power distribution. This divides current to avoid overloading individual tra...
TECHNICAL NOTE:If you need more information about wire conductor size, please see ourFAQ section on wire. Specifically, take a look at thearticle on voltage loss tables and ampacity for AWG wire sizes. A roof-mounted system will also use a combiner box. It serves the same functi...
The conductor system, i.e., bushings and wire sizes, help determine a design ampacity. The cooling system, air-cooled or oil-cooled, is also used to determine the ampacity of the transformer. Unless indicated otherwise, transformers are rated for a load factor of 100%. The current flowing ...
The motor thermal protection is based on a calculated model which uses the output current of the drive to determine the load on the motor. The thermal current IT specifies the load current above which the motor is overloaded. See figure 10.5.1-1. If the motor current is above the curve,...