NCCER ELECTRICAL MODULE 2
COMPREHENSIVE STUDY GUIDE 2026
CORE ELECTRICAL CONCEPTS
SOLUTIONS VERIFIED A+
◉ For the transformer 25-ft tap rule, the primary tap conductors
must have an ampacity of at least ____ of the feeder's OCPD rating.
Answer: * one-third * - NEC Section 240.21(B)(3) - The tap
conductors powering the primary winding of the transformer have
an ampacity at least one-third of the feeder conductor's overcurrent
protective device rating.
◉ For the transformer 25-ft tap rule, the secondary tap conductors
must have an ampacity at least the transformer's voltage ratio
multiplied by ____ of the feeder OCPD rating.
Answer: * one-third * - NEC Section 240.21(B)(3) - The tap
conductors connected to the secondary winding of the transformer
have an ampacity equal to or greater than the value of the
transformer's primary-to-secondary voltage ratio multiplied by one-
third of the feeder conductor's overcurrent protective device rating.
◉ The tap rule for high-bay manufacturing buildings in NEC
240.21(B)(4) applies when the building is over ____ high at its walls.
,Answer: * ____ * - NEC Section 240.21(B)(4) - ...in high-bay
manufacturing buildings over ____ high at its walls when all the
following conditions are met:
◉ Under the high-bay tap rule, what restriction must be in place
regarding facility policies?
Answer: * Facility policies must restrict servicing of the system to
qualified persons. * - NEC Section 240.21(B)(4) - Facility policies
restrict servicing of the system to qualified persons.
◉ For the high-bay tap rule, the tap conductors must not be over ____
long horizontally and their total length must not exceed ____.
Answer: * ____ ; ____ * - NEC Section 240.21(B)(4) - The tap
conductors are not over ____ long horizontally and their total length
does not exceed ____.
◉ For the high-bay tap rule, the tap conductor ampacity must be at
least ____ of the feeder OCPD rating.
Answer: * one-third * - NEC Section 240.21(B)(4) - The ampacity of
the tap conductors is equal to or greater than one-third of the rating
of the feeder conductor's overcurrent protective device.
◉ In the high-bay tap rule, must the tap conductors be protected
from physical damage?
, Answer: * Yes. * - NEC Section 240.21(B)(4) - The tap conductors are
protected from physical damage.
◉ What is the minimum size for copper tap conductors under the
high-bay tap rule?
Answer: * No. 6 AWG copper. * - NEC Section 240.21(B)(4) - The tap
conductors are at least No. 6 AWG copper or No. 4 AWG aluminum in
size.
◉ What is the minimum size for aluminum tap conductors under the
high-bay tap rule?
Answer: * No. 4 AWG aluminum. * - NEC Section 240.21(B)(4) - The
tap conductors are at least No. 6 AWG copper or No. 4 AWG
aluminum in size.
◉ Are splices permitted in tap conductors under the high-bay tap
rule?
Answer: * No, they must be continuous from end to end. * - NEC
Section 240.21(B)(4) - The tap conductors have no splices
(continuous from end to end).
◉ True or False: Under the high-bay tap rule, tap conductors are
permitted to pass through walls, floors, or ceilings.
Answer: * False. * - NEC Section 240.21(B)(4) - The tap conductors
do not pass through any walls, floors, or ceilings.
COMPREHENSIVE STUDY GUIDE 2026
CORE ELECTRICAL CONCEPTS
SOLUTIONS VERIFIED A+
◉ For the transformer 25-ft tap rule, the primary tap conductors
must have an ampacity of at least ____ of the feeder's OCPD rating.
Answer: * one-third * - NEC Section 240.21(B)(3) - The tap
conductors powering the primary winding of the transformer have
an ampacity at least one-third of the feeder conductor's overcurrent
protective device rating.
◉ For the transformer 25-ft tap rule, the secondary tap conductors
must have an ampacity at least the transformer's voltage ratio
multiplied by ____ of the feeder OCPD rating.
Answer: * one-third * - NEC Section 240.21(B)(3) - The tap
conductors connected to the secondary winding of the transformer
have an ampacity equal to or greater than the value of the
transformer's primary-to-secondary voltage ratio multiplied by one-
third of the feeder conductor's overcurrent protective device rating.
◉ The tap rule for high-bay manufacturing buildings in NEC
240.21(B)(4) applies when the building is over ____ high at its walls.
,Answer: * ____ * - NEC Section 240.21(B)(4) - ...in high-bay
manufacturing buildings over ____ high at its walls when all the
following conditions are met:
◉ Under the high-bay tap rule, what restriction must be in place
regarding facility policies?
Answer: * Facility policies must restrict servicing of the system to
qualified persons. * - NEC Section 240.21(B)(4) - Facility policies
restrict servicing of the system to qualified persons.
◉ For the high-bay tap rule, the tap conductors must not be over ____
long horizontally and their total length must not exceed ____.
Answer: * ____ ; ____ * - NEC Section 240.21(B)(4) - The tap
conductors are not over ____ long horizontally and their total length
does not exceed ____.
◉ For the high-bay tap rule, the tap conductor ampacity must be at
least ____ of the feeder OCPD rating.
Answer: * one-third * - NEC Section 240.21(B)(4) - The ampacity of
the tap conductors is equal to or greater than one-third of the rating
of the feeder conductor's overcurrent protective device.
◉ In the high-bay tap rule, must the tap conductors be protected
from physical damage?
, Answer: * Yes. * - NEC Section 240.21(B)(4) - The tap conductors are
protected from physical damage.
◉ What is the minimum size for copper tap conductors under the
high-bay tap rule?
Answer: * No. 6 AWG copper. * - NEC Section 240.21(B)(4) - The tap
conductors are at least No. 6 AWG copper or No. 4 AWG aluminum in
size.
◉ What is the minimum size for aluminum tap conductors under the
high-bay tap rule?
Answer: * No. 4 AWG aluminum. * - NEC Section 240.21(B)(4) - The
tap conductors are at least No. 6 AWG copper or No. 4 AWG
aluminum in size.
◉ Are splices permitted in tap conductors under the high-bay tap
rule?
Answer: * No, they must be continuous from end to end. * - NEC
Section 240.21(B)(4) - The tap conductors have no splices
(continuous from end to end).
◉ True or False: Under the high-bay tap rule, tap conductors are
permitted to pass through walls, floors, or ceilings.
Answer: * False. * - NEC Section 240.21(B)(4) - The tap conductors
do not pass through any walls, floors, or ceilings.
