LATEST COMMERCIAL ELECTRICAL
INSPECTOR (E2) CERTIFICATION EXAM
OFFERED BY INTERNATIONAL CODE
COUNCIL (ICC) | Q&A WITH RATIONALES
1. Article 100 of the NEC defines a "feeder" as:
A) The conductors between the service point and the
service disconnect
B) The conductors between the service equipment
and the final branch circuit overcurrent device
C) All circuit conductors between the service
equipment, the source of a separately derived
system, or other power supply source and the final
branch-circuit overcurrent device
D) The conductors that supply power to utilization
equipment
Correct answer: C
Rationale: NEC Article 100 defines a feeder as all
circuit conductors between the service equipment,
the source of a separately derived system, or other
power supply source and the final branch-circuit
overcurrent device. This is distinct from branch
circuits and service conductors.
,**2. In commercial electrical inspection, which of the
following is true regarding the approval of electrical
equipment?**
A) Field labeling is not recognized by the NEC
B) All equipment must be listed by a single Nationally
Recognized Testing Laboratory (NRTL)
C) Equipment must be approved, with listing and
labeling by an NRTL serving as a primary means of
demonstrating compliance
D) The inspector may approve any equipment based
solely on past experience
Correct answer: C
Rationale: NEC 110.2 requires that all electrical
equipment be approved. Listing and labeling by a
Nationally Recognized Testing Laboratory (NRTL)
provides evidence that equipment meets applicable
product safety standards.
**3. What is the minimum working space required in
front of a 480-volt panelboard with exposed live parts
on both sides?**
A) 3 feet
B) 3.5 feet
C) 4 feet
,D) 5 feet
Correct answer: C
Rationale: NEC Table 110.26(A)(1) specifies the
minimum depth of working space. For voltages
between 151 and 600 volts with exposed live parts on
both sides, the minimum working space is 4 feet.
**4. A commercial building has a 2000A feeder tap.
According to NEC 240.21(B)(1), the tap conductors
must terminate in a single circuit breaker or set of
fuses that limits the load to the ampacity of the tap
conductors. This is known as the:**
A) 25-foot tap rule
B) 10-foot tap rule
C) Secondary conductor rule
D) Outside feeder tap rule
Correct answer: B
Rationale: NEC 240.21(B)(1) contains the 10-foot tap
rule, which permits tap conductors without
overcurrent protection at the tap point provided the
tap conductors are not longer than 10 feet.
**5. A commercial building is fed from a pad-mounted
transformer outside the building. The required clear
, working space in front of this service equipment is
based on the voltage to ground and the presence of
exposed live parts on both sides. If the line-to-line
voltage is 480 volts and live parts are exposed on
both sides, the minimum depth of the working space
is:**
A) 3 ft
B) 3.5 ft
C) 4 ft
D) 5 ft
Correct answer: C
Rationale: NEC Table 110.26(A)(1) requires 4 feet of
working space for 151–600 V with exposed live parts
on both sides, regardless of whether the building is
fed from an outdoor transformer.
**6. What is the smallest size copper equipment
grounding conductor (EGC) required for a 400-amp
feeder?**
A) 4 AWG
B) 2 AWG
C) 1/0 AWG
D) 3 AWG
Correct answer: D
INSPECTOR (E2) CERTIFICATION EXAM
OFFERED BY INTERNATIONAL CODE
COUNCIL (ICC) | Q&A WITH RATIONALES
1. Article 100 of the NEC defines a "feeder" as:
A) The conductors between the service point and the
service disconnect
B) The conductors between the service equipment
and the final branch circuit overcurrent device
C) All circuit conductors between the service
equipment, the source of a separately derived
system, or other power supply source and the final
branch-circuit overcurrent device
D) The conductors that supply power to utilization
equipment
Correct answer: C
Rationale: NEC Article 100 defines a feeder as all
circuit conductors between the service equipment,
the source of a separately derived system, or other
power supply source and the final branch-circuit
overcurrent device. This is distinct from branch
circuits and service conductors.
,**2. In commercial electrical inspection, which of the
following is true regarding the approval of electrical
equipment?**
A) Field labeling is not recognized by the NEC
B) All equipment must be listed by a single Nationally
Recognized Testing Laboratory (NRTL)
C) Equipment must be approved, with listing and
labeling by an NRTL serving as a primary means of
demonstrating compliance
D) The inspector may approve any equipment based
solely on past experience
Correct answer: C
Rationale: NEC 110.2 requires that all electrical
equipment be approved. Listing and labeling by a
Nationally Recognized Testing Laboratory (NRTL)
provides evidence that equipment meets applicable
product safety standards.
**3. What is the minimum working space required in
front of a 480-volt panelboard with exposed live parts
on both sides?**
A) 3 feet
B) 3.5 feet
C) 4 feet
,D) 5 feet
Correct answer: C
Rationale: NEC Table 110.26(A)(1) specifies the
minimum depth of working space. For voltages
between 151 and 600 volts with exposed live parts on
both sides, the minimum working space is 4 feet.
**4. A commercial building has a 2000A feeder tap.
According to NEC 240.21(B)(1), the tap conductors
must terminate in a single circuit breaker or set of
fuses that limits the load to the ampacity of the tap
conductors. This is known as the:**
A) 25-foot tap rule
B) 10-foot tap rule
C) Secondary conductor rule
D) Outside feeder tap rule
Correct answer: B
Rationale: NEC 240.21(B)(1) contains the 10-foot tap
rule, which permits tap conductors without
overcurrent protection at the tap point provided the
tap conductors are not longer than 10 feet.
**5. A commercial building is fed from a pad-mounted
transformer outside the building. The required clear
, working space in front of this service equipment is
based on the voltage to ground and the presence of
exposed live parts on both sides. If the line-to-line
voltage is 480 volts and live parts are exposed on
both sides, the minimum depth of the working space
is:**
A) 3 ft
B) 3.5 ft
C) 4 ft
D) 5 ft
Correct answer: C
Rationale: NEC Table 110.26(A)(1) requires 4 feet of
working space for 151–600 V with exposed live parts
on both sides, regardless of whether the building is
fed from an outdoor transformer.
**6. What is the smallest size copper equipment
grounding conductor (EGC) required for a 400-amp
feeder?**
A) 4 AWG
B) 2 AWG
C) 1/0 AWG
D) 3 AWG
Correct answer: D
