Journeyman Electrician's Service and Feeder Calculations Flashcards
7 cards from real Journeyman Electrician’s Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Journeyman Electrician's Service and Feeder Calculations flashcards as text
For a 3,600 sq ft single-family dwelling using the standard method, how many 20A small appliance branch circuits are required, and what is their total VA load in the service calculation?
Answer: 2 circuits, 3,000 VA
NEC 210.11(C)(1) requires at least two 20A small appliance circuits, each at 1,500 VA = 3,000 VA total per NEC 220.52.
A service panel is supplied by a 500 kcmil aluminum feeder. What is the ampacity of this conductor using the 75°C column of NEC Table 310.15(B)(16)?
Answer: 310 A
Per NEC Table 310.15(B)(16), 500 kcmil aluminum at 75°C has an ampacity of 310A.
What additional load must be included in a service calculation for a dwelling that has a dedicated 20A laundry circuit per NEC 220.52(B)?
Answer: 1,500 VA
NEC 220.52(B) requires 1,500 VA for each required laundry circuit in the service load calculation.
When four current-carrying conductors are in a conduit, the ampacity adjustment factor per NEC 310.15(C)(1) is:
Answer: 80%
NEC Table 310.15(C)(1) requires an 80% adjustment factor when 4–6 current-carrying conductors share a raceway.
A service calculation for a 3,000 sq ft home includes general lighting, two small appliance circuits, one laundry circuit, a 12 kW range, and a 5 kW dryer. Using standard demand factors, what is the demand on the first 3,000W of the general lighting load?
Answer: 100%
Per NEC Table 220.42, the first 3,000 VA of residential lighting load is taken at 100% demand.
A 200A service is fed through 100 feet of 2/0 AWG copper conductors. If the calculated load is 175A, does this installation meet NEC requirements?
Answer: Yes, because 2/0 AWG copper is rated 175A at 75°C
NEC Table 310.15(B)(16) rates 2/0 AWG copper at 175A (75°C), which matches the 175A calculated load, satisfying NEC requirements.
Per NEC 220.14(J), what load in VA must be included for each receptacle outlet in a commercial or industrial occupancy (other than a dwelling) when calculating branch circuit or feeder loads?
Answer: 180 VA per outlet
NEC 220.14(J) assigns 180 VA per single or duplex receptacle outlet in non-dwelling occupancies.