Conductor Sizing and Protection Calculations Flashcards
Conductors 8 AWG in larger must be of the ___ type
Stranded
When the ampacity requirement of a circuit doesn’t correspond to a standard overcurrent protection size, it is allowable to size up in only in what conditions?
The conductors aren’t part of a branch circuit supplying multiple receptacles for cord and plug connected loads
The ampacity adjustment and correction factors don’t correspond to a standard wire size
The overcurrent device is rated less than 800a
Table for ambient temperature adjustment
310.15(B)(2)(a)
Table for conductor bundling adjustment
310.15(B)(3)(a)
The secondary conductors of a transformer must not be rated less than ___
(the amount of turns in the coil) primary/secondary ratio x the OCPD of the primary
Where cables or raceways are installed on a rooftop and exposed to sunlight and where are installed less than ___ from the roof, a ___F temperature adder will be added to the ambient temperature
7/8”
60
Raceways/cable assemblies with a length of ___” or less are not subject to bundling correction factors
24”
Bundling adjustments don’t apply to MC or AC cable when the following are true
The cables have no outer jacket
Each cable has no more than three current carrying conductors
The conductors are 12AWG copper
No more than 20 current carrying conductors are installed without maintaining spacing for a continuous length longer than 24”
The neutral conductor is to be considered current carrying when more than ___% of the load is made up of non-harmonic loads
50
When more than ___ current carrying conductors are installed in a wireway, the additional wires installed are to have their ampacity adjusted by bundling corrections
30
10’ feeder taps are permitted assuming they comply with the following conditions
The conductors must not have an ampacity less than:
The calculated load per art 220
The rating of the OCPD they are feeding
They must not extend beyond the equipment they are feeding
The conductors are installed inside a raceway
The conductors have a rating not less 1/10th the OCPD rating that is protecting them
25’ Feeder taps are permitted assuming they comply with the following conditions
The ampacity of the tap conductors have a rating not less than 1/3rd the OCPD that is protecting them
The tap conductors terminate in an OCPD that has a rating no less than the ampacity rating of the OCPD
Outside feeder taps of unlimited length are permitted assuming they comply with the following conditions
The conductors are within a raceway or protected from physical damage
The feeder conductors terminate in an OCPD that limits their load
The OCPD the tap conductors terminate in is part of the building feeder disconnect
The building feeder disconnect is readily accessible
An example of a non-linear lighting load would be a ___ fixture
Fluorescent
