Courtesy of www.MikeHolt.com.
All questions and answers are based on the 2023 NEC.
Q1: Where two dwelling units are supplied by a single feeder or service and the calculated load under Part III of Art. 220 exceeds that for _____ identical units calculated under Sec. 220.84, the lesser of the two loads is permitted to be used.
a) two
b) three
c) four
d) five
Q2: Equipment enclosures for circuit breakers or fuses applied in compliance with the series combination ratings marked on the equipment by the manufacturer in accordance with Sec. 240.86(B) shall be _____ to indicate the equipment has been applied with a series combination rating.
a) legibly marked in the field
b) inspected and tagged
c) installed
d) listed
Q3: A conduit run between a conduit seal and the point at which the conduit leaves a Class I, Division 1 location shall contain no union, coupling, box, or other fitting except for a listed _____ reducer installed at the conduit seal.
a) explosionproof
b) fireproof
c) vaportight
d) dusttight
Q4: A separate overload device used to protect continuous-duty motors rated more than 1 hp shall be selected to trip at no more than _____ of the motor nameplate full-load current rating if marked with a service factor of 1.15 or greater.
a) 100%
b) 110%
c) 125%
d) 140%
Q5: All conductors of the same circuit, including the grounded and equipment grounding conductors and bonding conductors shall be contained within the same _____, unless otherwise permitted elsewhere in the Code.
a) raceway
b) conduit body
c) trench
d) all of these
Q6: In a Class III hazardous location where ignitible fibers/flyings are present, the maximum surface temperatures under operating conditions shall not exceed _____ for equipment that might be overloaded.
a) 75°C
b) 90°C
c) 104°C
d) 120°C
Answers:
Q1: b) three
Per Sec.220.85:"Where two dwelling units are supplied by a single feeder or service and the calculated load under Part III of this article exceeds that for three identical units calculated under Sec. 220.84, the lesser of the two loads shall be permitted to be used."
Q2: a) legibly marked in the field
Section 110.22(C) confirms, "Equipment enclosures for circuit breakers or fuses applied in compliance with the series combination ratings marked on the equipment by the manufacturer in accordance with Sec. 240.86(B) shall be legibly marked in the field to indicate the equipment has been applied with a series combination rating."
Q3: a) explosionproof
Per Sec. 501.15(A)(4): "The conduit run between the conduit seal and the point at which the conduit leaves the Division 1 location shall contain no union, coupling, box, or other fitting except for a listed explosionproof reducer installed at the conduit seal."
Q4: c) 125%
Section 430.32(A)(1) specifies 125% for motors with a marked service factor 1.15 or greater.
Q5: d) all of these
As stated in Sec. 300.3(B), all conductors of the same circuit, including the grounded and equipment grounding conductors and bonding conductors "shall be contained within the same raceway, conduit body, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord unless otherwise permitted."
Q6: d) 120°C
According to Sec. 500.8(D)(3)(b), "When ignitible fibers/flyings are present, the maximum surface temperatures under operating conditions shall not exceed 165°C for equipment that is not subject to overloading, and 120°C for equipment that might be overloaded."
These materials are provided by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.
