Michigan Electrical Inspector {National Electrical Code}
Competency Study Guide
Comprehensive Resource To Help You Ace 2026-2027 Exams
Includes Frequently Tested Questions With ELABORATED
100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
1. Given: after all demand factors have been taken into consideration for an
office building, the demand load is determined to be 90,000 VA; the
building has a 120/240-volt, single phase electrical system. What MIN. size
copper conductors with THHN/THWN insulation are required for the
ungrounded service-lateral conductors? Consider all termination lugs are
rated for 75 deg. C.
A. 400 kcmil
B. 350 kcmil
C. 300 kcmil
D. 500 kcmil - Correct Answer: D. 500 kcmil
2. Given: a commercial building is to be supplied from a transformer having a
480Y/277-volt, 3 phase primary and a 208Y/120-volt, 3 phase secondary.
The secondary will have a balanced computed demand load of 416 amperes
per phase. The transformer is required to have a MIN kVA rating of ____.
A. 100 kVA
B. 150 kVA
C. 86 kVA
D. 200 kVA - Correct Answer: B. 150 kVA
,3. Manhole covers shall be OVER ____ or otherwise designed to require the
use of tools to open.
A. 25 lbs.
B. 50 lbs.
C. 75 lbs.
D. 100 lbs - Correct Answer: D. 100 lbs
4. The branch circuit conductors supplying one or more units of information
technology equipment shall have an ampacity of NOT less than ____ of the
connected load.
A. 80%
B. 100%
C. 115%
D. 125% - Correct Answer: D. 125%
5. In regard to a 7.5 hp, 480-volt, 3 phase ac motor with an 80% power factor
and a full-load ampere rating of 19 amperes indicated on the nameplate,
and a service factor of 1.15; when the initial setting of the overload device
you have selected is not sufficient to carry the load, what is the MAX.
setting permitted for the overload protection?
A. 21.85 amperes
B. 23.75 amperes
C. 24.7 amperes
D. 26.6 amperes - Correct Answer: D. 26.6 amperes
6. The ampacity adjustment factors for conductors addressed in Section
310.15(C)(1) of the NEC are not required to be applied when the conductors
are installed in a metal wireway unless, the number of current-carrying
conductors within the wireway exceeds at least ____ at any cross-section
area of the wireway.
, A. 20
B. 30
C. 35
D. 24 - Correct Answer: B. 30
7. What MIN. voltage is require after 1.5 hours to serve emergency lighting
from a storage battery when the normal source voltage of 120 volts is
interrupted?
A. 60 volts
B. 90 volts
C. 105 volts
D. 120 volts - Correct Answer: C. 105 volts
8. Determine the MAX. ampere setting permitted for an overload protective
device responsive to motor current, where used to protect a 20 hp, 240-
volt, 3 phase, induction type ac motor with a temperature rise of 48 deg. C
and a FLA of 54 amperes indicated on the nameplate.
A. 54 amperes
B. 70.2 amperes
C. 62.1 amperes
D. 75.6 amperes - Correct Answer: B. 70.2 amperes
9. Where Type SRD multiconductor cable consist of size 8 AWG conductors
and only 2 conductors in the cable are current-carrying, what is the
ampacity of the conductors?
A. 20 amperes
B. 30 amperes
C. 40 amperes
D. 50 amperes - Correct Answer: C. 40 amperes
, 10.Aluminum or steel cable trays shall be permitted to be used as equipment
grounding conductors, provided ____.
the cable tray sections and fittings are identified as an equipment grounding
conductor.
the cable tray sections and fittings are durably marked to show the cross-
sectional area of the metal.
A. I only
B. II only
C. neither I nor II
D. both I and II - Correct Answer: D. both I and II
11.When intermediate metal conduit is threaded in the field, a standard
cutting die with a ____ taper per ft. shall be used.
A. 3/8 in.
B. 1/2 in.
C. 3/4 in.
D. 1 in. - Correct Answer: C. 3/4 in.
12.In regard to emergency systems, where internal combustion engines are
used as the prime movers, they shall NOT be solely dependent on a public
utility gas system for their fuel supply, unless ____.
A. it is acceptable to the authority having jurisdiction
B. the gas system is listed and approved
C. the gas system and electrical utility are jointly owned and maintained
D. none of these apply - Correct Answer: A. it is acceptable to the
authority having jurisdiction
Competency Study Guide
Comprehensive Resource To Help You Ace 2026-2027 Exams
Includes Frequently Tested Questions With ELABORATED
100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
1. Given: after all demand factors have been taken into consideration for an
office building, the demand load is determined to be 90,000 VA; the
building has a 120/240-volt, single phase electrical system. What MIN. size
copper conductors with THHN/THWN insulation are required for the
ungrounded service-lateral conductors? Consider all termination lugs are
rated for 75 deg. C.
A. 400 kcmil
B. 350 kcmil
C. 300 kcmil
D. 500 kcmil - Correct Answer: D. 500 kcmil
2. Given: a commercial building is to be supplied from a transformer having a
480Y/277-volt, 3 phase primary and a 208Y/120-volt, 3 phase secondary.
The secondary will have a balanced computed demand load of 416 amperes
per phase. The transformer is required to have a MIN kVA rating of ____.
A. 100 kVA
B. 150 kVA
C. 86 kVA
D. 200 kVA - Correct Answer: B. 150 kVA
,3. Manhole covers shall be OVER ____ or otherwise designed to require the
use of tools to open.
A. 25 lbs.
B. 50 lbs.
C. 75 lbs.
D. 100 lbs - Correct Answer: D. 100 lbs
4. The branch circuit conductors supplying one or more units of information
technology equipment shall have an ampacity of NOT less than ____ of the
connected load.
A. 80%
B. 100%
C. 115%
D. 125% - Correct Answer: D. 125%
5. In regard to a 7.5 hp, 480-volt, 3 phase ac motor with an 80% power factor
and a full-load ampere rating of 19 amperes indicated on the nameplate,
and a service factor of 1.15; when the initial setting of the overload device
you have selected is not sufficient to carry the load, what is the MAX.
setting permitted for the overload protection?
A. 21.85 amperes
B. 23.75 amperes
C. 24.7 amperes
D. 26.6 amperes - Correct Answer: D. 26.6 amperes
6. The ampacity adjustment factors for conductors addressed in Section
310.15(C)(1) of the NEC are not required to be applied when the conductors
are installed in a metal wireway unless, the number of current-carrying
conductors within the wireway exceeds at least ____ at any cross-section
area of the wireway.
, A. 20
B. 30
C. 35
D. 24 - Correct Answer: B. 30
7. What MIN. voltage is require after 1.5 hours to serve emergency lighting
from a storage battery when the normal source voltage of 120 volts is
interrupted?
A. 60 volts
B. 90 volts
C. 105 volts
D. 120 volts - Correct Answer: C. 105 volts
8. Determine the MAX. ampere setting permitted for an overload protective
device responsive to motor current, where used to protect a 20 hp, 240-
volt, 3 phase, induction type ac motor with a temperature rise of 48 deg. C
and a FLA of 54 amperes indicated on the nameplate.
A. 54 amperes
B. 70.2 amperes
C. 62.1 amperes
D. 75.6 amperes - Correct Answer: B. 70.2 amperes
9. Where Type SRD multiconductor cable consist of size 8 AWG conductors
and only 2 conductors in the cable are current-carrying, what is the
ampacity of the conductors?
A. 20 amperes
B. 30 amperes
C. 40 amperes
D. 50 amperes - Correct Answer: C. 40 amperes
, 10.Aluminum or steel cable trays shall be permitted to be used as equipment
grounding conductors, provided ____.
the cable tray sections and fittings are identified as an equipment grounding
conductor.
the cable tray sections and fittings are durably marked to show the cross-
sectional area of the metal.
A. I only
B. II only
C. neither I nor II
D. both I and II - Correct Answer: D. both I and II
11.When intermediate metal conduit is threaded in the field, a standard
cutting die with a ____ taper per ft. shall be used.
A. 3/8 in.
B. 1/2 in.
C. 3/4 in.
D. 1 in. - Correct Answer: C. 3/4 in.
12.In regard to emergency systems, where internal combustion engines are
used as the prime movers, they shall NOT be solely dependent on a public
utility gas system for their fuel supply, unless ____.
A. it is acceptable to the authority having jurisdiction
B. the gas system is listed and approved
C. the gas system and electrical utility are jointly owned and maintained
D. none of these apply - Correct Answer: A. it is acceptable to the
authority having jurisdiction
