Ampacities
#1
Ampacities
Could someone tell me what are the ampacities of #14 thru #4 copper wire under 'normal' conditions?
#7
There are lots of times you will need to derate or increase the basic conductors ampacity. Just a few include more than 3 current carring conductors in a raceway, the termination temperature rating of what you are connecting to, motor loads relative to breaker/fuse size, etc.
#8
Be sure to consider these factors when deciding whether your situation is normal: (1) number of conductors running in the same raceway or cable, (2) type of insulation or the wire, (3) type of sheathing on the cable, (4) type of cable -- there are special ampacity rules for NM, SE, UF, etc., (5) whether the installation is wet or dry, (6) whether the installation is above ground or underground (7) ambient temperature through which the wires run, (8) material from which the wires are made, (9) purpose of the conductors, e.g., whether they are used as feeders, branch circuits, or services.
All of these factors can affect the ampacity. Maybe others can think of more factors.
Once the ampacity of the wire is determined, then you need to determine the proper breaker size to protect that wire. They are not always the same number.
All of these factors can affect the ampacity. Maybe others can think of more factors.
Once the ampacity of the wire is determined, then you need to determine the proper breaker size to protect that wire. They are not always the same number.