TL;DR
Learn branch circuit and feeder sizing requirements, overcurrent protection, and load calculations. Circuit design is a core competency for licensed electricians and heavily tested.
Free Outside Branch Circuits & Feeders (Art. 225) Practice Questions
Master Electrician License Exam · Services & Feeders
This module covers Outside Branch Circuits & Feeders (Art. 225) as part of the Services & Feeders section, testing your understanding of core concepts and their practical application.
| Exam | Master Electrician License Exam |
| Pass Rate | 45% |
| Duration | 300 minutes |
| Module | Outside Branch Circuits & Feeders (Art. 225) |
Why Outside Branch Circuits & Feeders (Art. 225) matters
Outside Branch Circuits & Feeders (Art. 225) is a commonly tested topic on the Master Electrician License Exam because it covers fundamental knowledge required for competent professional practice.
Sample Practice Questions (5)
1. A 480V, 3-phase overhead feeder runs 300 feet between two commercial buildings. Per NEC 225.18, what is the minimum clearance of these conductors over an area subject to truck traffic?
- 18 feet
- 15 feet
- 12 feet
- 10 feet
2. A farm property has four separate buildings fed from the service in the main barn. Per NEC 225.30 and 225.32, each building needs its own disconnect. How many total disconnects are permitted at each outbuilding?
- Up to six disconnects grouped at one location per building, per NEC 225.33(A)
- Only one disconnect per building, no exceptions
- Up to two disconnects per building
- Unlimited disconnects if labeled
3. A detached garage is fed by a 60A feeder from the house panel. Per NEC 225.32 and 225.36, the disconnect at the garage must meet all of the following requirements EXCEPT:
- The disconnect must have ground-fault protection for equipment (GFPE)
- The disconnect must be suitable for use as service equipment
- The disconnect must be readily accessible
- The disconnect must be installed nearest the point of entrance of conductors
Want more practice like this?
Start practicing free →4. Per NEC 225.26, overhead branch circuit and feeder conductors must have a maximum span of how many feet between supports, unless specifically engineered?
- No specific maximum span is given in 225.26; spans must be adequate to maintain required clearances
- 50 feet maximum
- 100 feet maximum
- 150 feet maximum
5. Per NEC 225.30, how many feeder or branch circuit supplies are permitted to a building or structure?
- One, unless additional supplies are permitted by exceptions such as for fire pumps, emergency systems, or parallel power production
- Unlimited, as long as each has a disconnect
- Two maximum
- One for residential, three for commercial
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