Sample Calculation:
Four “#14/2 w/ground' cables:
Eight insulated wires…………264.4 cubic centimeters 16 cu in
All ground wires………………..32.8 cubic centimeters 2 cu in
One switch……………………..65.6 cubic centimeters 4 cu in
One receptacle………………...65.6 cubic centimeters 4 cu in
All clamps………………………32.8 cubic centimeters 2 cu in
Total box volume required….461.2 cubic centimeters 28 cu in
34 NEC 410.8 Luminaires (lighting fixtures) installed in clothes closets shall have the following minimum clearances from the defined storage area
(see the definition below):
300 mm [12"] for surface incandescent fixtures
150 mm [6"] for recessed incandescent fixtures
150 mm [6"] for fluorescent fixtures
35 NEC 410.8 Storage space, as applied to an electrical installation in a closet, is the volume bounded by the sides and back closet walls and
planes extending from the closet floor vertically to a height of 1.8 m [6 ft] or the highest clothes-hanging rod and parallel to the walls at a horizontal
distance of 600 mm [241 from the sides and back of the closet walls respectively, and continuing vertically to the closet ceiling parallel to the walls at
a horizontal distance of 300 mm [121 or the width of the shelf, whichever is greater.
36 NEC 410.8 Incandescent luminaires with open or partially enclosed lamps and pendant fixtures or lampholders are not permitted in clothes
closets.
37 NEC 410-66 Recessed lighting fixtures installed in insulated ceilings or installed within 13 mm [1/29 of combustible material shall be approved for
insulation contact and labeled as Type IC.
The Minnesota Energy Code, part of the State Building Code,
requires penetrations into exterior walls and ceilings to be
sealed to prevent the leakage of airborne moisture into unheated spaces.
38 Minnesota Rules 3800.3620 All electrical equipment, including luminaires, devices, and appliances shall be LISTED AND LABELED by a
nationally recognized testing laboratory as having been tested and found suitable for a specific purpose. Underwriters Laboratories (UL) and the
Canadian Standards Association (CSA) are two of the recognized agencies.
39 NEC 110.3 All electrical equipment shall be installed and used in accordance with the listing requirements and manufacturer's instructions.
Electrical Services
40 NEC 310-15 CONDUCTOR SIZES FOR 120/240 VOLT
SINGLE-PHASE DWELLING SERVICES AND FEEDER
Copper Aluminum Service Rating
4 AWG 2 AWG 100 amps
1 AWG 2/0 150 amps
2/0 4/0 200 amps
41 NEC 230.7 Conductors other than service conductors shall not be installed in the same service raceway or cable.
42 NEC 110.14 Conductors of dissimilar metals shall not be intermixed in a terminal or splicing device unless the device is listed for the purpose.
Listed anti-oxidant compound shall be used on all aluminum conductor terminations unless information from the device manufacturer specifically
states that it is not required.
43 NEC 300.7 Portions of raceways and sleeves subject to different temperatures (where passing from the interior to the exterior of a building) shall
be sealed with an approved material to prevent condensation from entering the service equipment.
44 NEC 230.54 Where exposed to weather, service entrance conductors shall be rain-'tight and arranged to drain.
45 NEC 300.4 Where raceways containing ungrounded conductors No. 4 or larger enter a cabinet, box, or enclosure, the conductors shall be
protected by a conduit bushing providing a smoothly rounded insulating surface.
46 NEC 230.70 The electrical service disconnecting means shall be installed at a readily accessible location either outside a building or structure or
inside nearest the point of entrance of the service-entrance conductors.
47 NEC 230.70 & 240.24 Electrical panels shall be readily accessible and shall not be located in bathrooms or in the vicinity of easily ignitable
materials such as clothes closets.
48 NEC 110.26 The depth of working space in the direction of access to live parts, when the voltage to ground does not exceed 150 volts, shall be a
minimum of 3 feet. The minimum width of working space in front of electrical equipment shall be the width of the equipment or 30 inches, whichever
is greater. This workspace shall be clear and extend from the floor to a height of 6½ feet This space shall not be used for storage.
49 NEC 110.26 Illumination shall be provided for all work spaces about electrical service equipment.
Grounding
50 NEC 250.50 A premises electrical service shall be connected to a grounding electrode system consisting of a metal underground water pipe in
direct contact with earth for 3.0 m [10'] or more, if available on the premises, and supplemented by a rod, pipe, or plate electrode.
An additional electrode must supplement
the buried water pipe electrode.
51 NEC 250.64 & 250.66 The grounding electrode conductor shall be unspliced. The size is determined by the size of the service-entrance
conductors, per the following chart::
Equivalent Size of Service
Entrance Conductor
Size of the Grounding
Electrode Conductor
Copper Aluminum Copper Aluminum
4 AWG 2 8 6
1 AWG 2/0 6 4
2/0 or 3/0 4/0 or 250 4 2
The grounding electrode conductor that is the sole
connection to a rod, pipe or plate electrode is not required
to be larger than #6 copper.
52 NEC 250.28 A main bonding jumper or the green bonding screw provided by the panel manufacturer shall be installed in the service panel to
electrically bond the grounded service conductor and the equipment grounding conductors to the service enclosure.
53 NEC 250.104 The interior metal water piping and other metal piping that may become energized shall be bonded to the service equipment with a
bonding jumper sized the same as the grounding electrode conductor.
54 NEC 300.5 Direct buried cable or conduit or other raceways shall meet the following minimum cover requirements: