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OREGON GENERAL SUPERVISING ELECTRICIAN Exam
2026-2027 BANK QUESTIONS WITH DETAILED VERIFIED
ANSWERS EXAM QUESTIONS WILL COME FROM HERE
(100 % Latest Already Graded A+
1. What is the minimum working clearance required in front of a
480/277-volt switchboard that requires servicing while energized,
where there are no live parts on the other side of the working space?
A. 2 feet
B. 3 feet
C. 3.5 feet
D. 4 feet
Answer: D. 4 feet
Explanation: Per NEC Article 110.26(A)(1), Condition 2, for systems rated
151V to 600V nominal to ground, the minimum depth of working space
from the exposed live parts on one side and no live or grounded parts on
the other side of the working space is 3.5 feet. However, the question
specifies a switchboard that requires servicing while energized. The
Oregon Specialty Codes, based on the NEC, frequently modify this for
specific equipment. For a standard 480Y/277V switchboard, the voltage
to ground is 277V, placing it in the 151-600V category. Condition 1
(exposed live parts on one side and grounded parts on the other)
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requires 3.5 feet, Condition 2 (exposed live parts on one side and
insulated parts on the other) requires 3 feet, and Condition 3 (exposed
live parts on both sides) requires 4 feet. Since the question does not
specify that the opposite wall is grounded, and for a supervising
electrician's exam, the most conservative and common interpretation
for a switchboard room with parts on one side and a grounded concrete
wall or another panel is Condition 1, but the question wording "no live
parts on the other side" typically points to Condition 2 (3.5 feet) or
Condition 3 if misinterpreted. The NEC clearly states that for 480Y/277V
systems, the voltage to ground is 277V. Table 110.26(A)(1) Condition 2
depth is 3.5 ft. The correct answer, cross-referenced with Oregon's
amendments, which often align tightly with the NEC for this table, is 3.5
feet. I apologize, I must correct my initial analysis: Condition 1
(grounded parts on the other side, like a concrete wall) is 3.5 ft,
Condition 2 (insulated parts) is 3 ft, Condition 3 (live parts on both sides)
is 4 ft. The question states "no live parts on the other side," which most
likely means the opposite surface is grounded or at ground potential,
making it Condition 1, requiring 3.5 feet. I will revise the answer.
Revised Answer: C. 3.5 feet. The table mandates 3.5 feet for 151-600V
under Condition 1, which is when exposed live parts are on one side and
grounded parts are on the other.
2. A rigid metal conduit is to be installed in a location subject to severe
physical damage. What is the minimum trade size allowed?
A. 1/2 inch
B. 3/4 inch
C. 1 inch
D. 1-1/4 inch
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Answer: A. 1/2 inch
Explanation: NEC Article 344.10(A)(1) states that rigid metal conduit
(RMC) shall be permitted in all atmospheric conditions and occupancies.
The minimum size for RMC, as specified in Article 300.1(C) for conduit
and tubing, is not universally restricted for physical damage except for
specific conduit types like Electrical Metallic Tubing (EMT), which under
NEC 358.12(1) is not permitted where subject to severe physical
damage. RMC, being a thick-walled steel conduit, is expressly permitted
for severe physical damage with no trade size minimum above the
standard 1/2 inch.
3. What is the maximum overcurrent protection allowed for a size 12
AWG THHN copper conductor used as a motor control circuit tapped
from a motor branch circuit, where the tap is made inside a controller
enclosure and is not more than 10 feet long?
A. 20 amperes
B. 30 amperes
C. 45 amperes
D. 60 amperes
Answer: C. 45 amperes
Explanation: According to NEC Article 430.72(B), for a control circuit
tapped from a motor branch circuit, if the tap is not over 10 feet long
and is enclosed, the overcurrent protection may be up to 45 amperes for
a 12 AWG conductor. Table 430.72(B) Column C specifically allows a 12
AWG copper conductor to be protected at 45A under these conditions.
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4. When supporting a junction box from a suspended ceiling, what is a
crucial requirement for the support wires?
A. They must be painted red for identification.
B. They must be a minimum of #12 AWG steel wire.
C. They must be independent from the ceiling grid support wires.
D. They must be attached directly to the building structure above, not
the ceiling grid.
Answer: C. They must be independent from the ceiling grid support
wires.
Explanation: NEC Article 300.11(A) states that raceways, cable
assemblies, and enclosures shall not be supported by the ceiling grid or
its support wires. The support wires used for the electrical enclosure
must be separate and independent from the acoustical ceiling grid's
support wires. They must also be fastened to the building structure
above.
5. A 3-phase, 4-wire, 208Y/120-volt feeder is to supply a continuous
load of 200 amperes. The feeder overcurrent device is a 100%-rated
circuit breaker. What is the minimum required ampacity of the feeder
conductors?
A. 200 amperes
B. 210 amperes
C. 240 amperes
D. 250 amperes
Answer: A. 200 amperes
OREGON GENERAL SUPERVISING ELECTRICIAN Exam
2026-2027 BANK QUESTIONS WITH DETAILED VERIFIED
ANSWERS EXAM QUESTIONS WILL COME FROM HERE
(100 % Latest Already Graded A+
1. What is the minimum working clearance required in front of a
480/277-volt switchboard that requires servicing while energized,
where there are no live parts on the other side of the working space?
A. 2 feet
B. 3 feet
C. 3.5 feet
D. 4 feet
Answer: D. 4 feet
Explanation: Per NEC Article 110.26(A)(1), Condition 2, for systems rated
151V to 600V nominal to ground, the minimum depth of working space
from the exposed live parts on one side and no live or grounded parts on
the other side of the working space is 3.5 feet. However, the question
specifies a switchboard that requires servicing while energized. The
Oregon Specialty Codes, based on the NEC, frequently modify this for
specific equipment. For a standard 480Y/277V switchboard, the voltage
to ground is 277V, placing it in the 151-600V category. Condition 1
(exposed live parts on one side and grounded parts on the other)
,2|Page
requires 3.5 feet, Condition 2 (exposed live parts on one side and
insulated parts on the other) requires 3 feet, and Condition 3 (exposed
live parts on both sides) requires 4 feet. Since the question does not
specify that the opposite wall is grounded, and for a supervising
electrician's exam, the most conservative and common interpretation
for a switchboard room with parts on one side and a grounded concrete
wall or another panel is Condition 1, but the question wording "no live
parts on the other side" typically points to Condition 2 (3.5 feet) or
Condition 3 if misinterpreted. The NEC clearly states that for 480Y/277V
systems, the voltage to ground is 277V. Table 110.26(A)(1) Condition 2
depth is 3.5 ft. The correct answer, cross-referenced with Oregon's
amendments, which often align tightly with the NEC for this table, is 3.5
feet. I apologize, I must correct my initial analysis: Condition 1
(grounded parts on the other side, like a concrete wall) is 3.5 ft,
Condition 2 (insulated parts) is 3 ft, Condition 3 (live parts on both sides)
is 4 ft. The question states "no live parts on the other side," which most
likely means the opposite surface is grounded or at ground potential,
making it Condition 1, requiring 3.5 feet. I will revise the answer.
Revised Answer: C. 3.5 feet. The table mandates 3.5 feet for 151-600V
under Condition 1, which is when exposed live parts are on one side and
grounded parts are on the other.
2. A rigid metal conduit is to be installed in a location subject to severe
physical damage. What is the minimum trade size allowed?
A. 1/2 inch
B. 3/4 inch
C. 1 inch
D. 1-1/4 inch
,3|Page
Answer: A. 1/2 inch
Explanation: NEC Article 344.10(A)(1) states that rigid metal conduit
(RMC) shall be permitted in all atmospheric conditions and occupancies.
The minimum size for RMC, as specified in Article 300.1(C) for conduit
and tubing, is not universally restricted for physical damage except for
specific conduit types like Electrical Metallic Tubing (EMT), which under
NEC 358.12(1) is not permitted where subject to severe physical
damage. RMC, being a thick-walled steel conduit, is expressly permitted
for severe physical damage with no trade size minimum above the
standard 1/2 inch.
3. What is the maximum overcurrent protection allowed for a size 12
AWG THHN copper conductor used as a motor control circuit tapped
from a motor branch circuit, where the tap is made inside a controller
enclosure and is not more than 10 feet long?
A. 20 amperes
B. 30 amperes
C. 45 amperes
D. 60 amperes
Answer: C. 45 amperes
Explanation: According to NEC Article 430.72(B), for a control circuit
tapped from a motor branch circuit, if the tap is not over 10 feet long
and is enclosed, the overcurrent protection may be up to 45 amperes for
a 12 AWG conductor. Table 430.72(B) Column C specifically allows a 12
AWG copper conductor to be protected at 45A under these conditions.
, 4|Page
4. When supporting a junction box from a suspended ceiling, what is a
crucial requirement for the support wires?
A. They must be painted red for identification.
B. They must be a minimum of #12 AWG steel wire.
C. They must be independent from the ceiling grid support wires.
D. They must be attached directly to the building structure above, not
the ceiling grid.
Answer: C. They must be independent from the ceiling grid support
wires.
Explanation: NEC Article 300.11(A) states that raceways, cable
assemblies, and enclosures shall not be supported by the ceiling grid or
its support wires. The support wires used for the electrical enclosure
must be separate and independent from the acoustical ceiling grid's
support wires. They must also be fastened to the building structure
above.
5. A 3-phase, 4-wire, 208Y/120-volt feeder is to supply a continuous
load of 200 amperes. The feeder overcurrent device is a 100%-rated
circuit breaker. What is the minimum required ampacity of the feeder
conductors?
A. 200 amperes
B. 210 amperes
C. 240 amperes
D. 250 amperes
Answer: A. 200 amperes
