ENVIRONMENTAL CONTROLS IN BUILDINGS - I I
BCN 4564
Author. MILTON E. MARTINEZ JR.
 
 

TABLE OF CONTENTS

Introduction
Floor Plan
Floor Plan w/ Dimensions
Electrical Plan
Residential Wiring Calculations
Wiring, Breaker, Junction Box and Conduit Calculations
Panel A
Panel B
Typical 120 V / 240 V; 150 A; Single Phase Riser
Typical Residential Riser; Main and Grounding for 120V / 240 V Single
Typical Residential Overhead Service
Typical 120 V / 240 V ; Single Phase Main Panel
Above Ground Minimum Clearance for Overhead Electrical Wires
Excerpt from Residential Wiring Code ( NEC 1996 )
Excerpt for Conduits ( NEC 1996 )
Electrical Symbols
Table 370-16 ( Allowance Ampacities of Insulated COnductors...)
Table 370-16 (a) ( Metal Boxes - Min.Cu.In. capacity )
Table 370-16 (b) ( Volume Required per Conductor ) - NEC 1996
Table 240-6 ( Standard Ampere Ratings ) - NEC 1996
Notes to Ampacity Tables of 0 to 2000 Volts - NEC 1996
Table 250-94 ( Grounding Electrode Conductor for AC Systems )
Table 250-95 ( Min. Size Equip. Grounding Conductors...) - NEC 1996
Table 4 ( Dimensions & Percentage Area of Conduit & Tubing )
Table 5 ( Dimensions of Insulated Conductors & Fixture wires ) - NEC
Table 8 ( Conductor Properties )
Table 430-148 ( Full-load Current in Amps, Single Phase Ac Motors )
Table 430-150 ( Full-load Current 3 Phase AC Motors ) - NEC 1996
Table 430-152 ( Max. Rating or Setting of Motor Branch Circuit...) NEC
Motors & Motor CIrcuits ( Name Plate info ) - H.Holzman
Table 430-7 (b) ( Locked Rotor Indicating Code Letters ) - Nec 1996
Typical Wiring for 4 Wire, 3 Phase, 230 V Source w/ 3 Phase Motor Load & Lighting Load
Table 220-3 (b) ( General Lighting Loads by Occupancies ) - NEC 1996


INTRODUCTION

This is an Electrical Remodeling of an existing residence.
Residence was built on/or about 1948 and Main panel did not have the capacity for the additional load required.
Existing Main was for 100A and the new load required a NEW 150A service.  The reason for the increase over the old Main was:
    Requirement for Service Disconnect @ Main Panel
    New Electrical Range with a greater power consumption
    New Central A/C
    New appliances:    Dishwasher
                                 Garbage Disposal
                                 Microwave
                                 Clothes Dryer
                                 Sprinkle Pump
                                 Additional Refrigerator
Hence, a New Main was added inside the garage and the old Main became a sub panel ( panel B ) for the New Main panel ( Panel A ).
The load was distributed where:
Panel A    Sub feed to Panel B
                    A/C Compressor & Air Handler
                    Water Sprinkler Pump
                    Clothes Dryer
                    Washing Machine
                    Additional Refrigerator
                    Exterior Lights and Receptacles
                    Garage Lights and Receptacles
Panel B    Range
                Refrigerator
                Dishwasher
                Microwave
                Garbage Disposal
                2 Small Appliance Circuits
                Lights and Receptacles for Inside the house
                Front Exterior Light



 Drawing 1

 Drawing 2

 Drawing 3



RESIDENTIAL WIRING CALCULATIONS
 
 
Give : 2,230 sq.ft. home  6.7 Kw [( 2230 sq.ft. )*( 3 w/sq.ft.)]
Range  9 Kw
A/C 12 Kw
Clothes Dryer 6 Kw
Water Heater 5 Kw
Garbage Disposal 0.8 Kw

 
DESCRIPTION VA ( Kw )
General Lighting  6,700
Range 9,000
Garbage Disposal 800
Refrigerator # 1 1,500
Refrigerator # 2 1,500
2 Small Appliance Circuits 3,000
Dishwasher 1,000
Water Heater 5,000
Clothes Dryer 6,000
Sprinkler Pump 2,400
Laundry ( Washing Machine ) 1,500
Total : 38,400
1st 10 Kva  @ 100 % 10,000
Bal. @ 40 % (28400 * 40 ) 11,360
A/C load @ 100 % 12,000
Total Load 33,360

I = P / V    = 33360 / 240 = 139.0 Amp
NOTE:     If I < 150 Amp USE 150 A

RISER:    3 # 1 THWN Cu Wires in 1 1/2 " Rigid Metallic Conduit
                1 # 6 Grounding Cu Wire, Mechanically protected



WIRING, BREAKER & CONDUIT CALCULATIONS

FORMULAS
 
To Determine Amperes needed VA / V = Amps
To Determine Wiring Use: Table 310-16 (1996 NEC )
To Determine Fuses & Fixed
Circuit Breakers Use:
Table 240-6 ( a ) ( 1996 NEC )
To Determine Dimension of 
Insulated Conductors & 
Fixture Wiring Use
Table 5, 1995 NFPA
To Determine Dimensions & 
Percentage Area of Conduit 
& Tubing Use:
Table 4, 1995 NFPA
To Determine # of Wiring in 
Tubing ( then match number from formula to Table 4, NFPA ) or, Use:
[ ( Area of Wires ) / ( Percentage Area ) ]
Appendix C, Table C-1 (1999 NEC ) Conduit & Fill Tables for Conduits & Fixtures of the Same Size
To Determine Volume of Wires Use: Table 370-16 ( b ) ( 1996 NEC )
To Determine Size of Metal Box Use: Table 370-16 ( a ) ( 1996 NEC )
To Determine Amps in Single Phase Motors Use: Table 430-148, 1996 NEC
Then for Current Calculation apply 125 % factor I = ( 125 % ) * ( Amps )
To Determine if wires will carry power NEED: D = Distance of Motor from Panel
Ohms / Kft for AWG Wire Size see:
( @ Table 8, 1996 NEC )
Amps ( Table 430-148 1996 NEC )
Max. Voltage Drop Percentage ( % ) =
V drop = ( Volts ) * ( Voltage Drop % ) = Volts' p (AWG Wire Size ) = [(ohms / Kft ) / 1000' ] * (# wires) * (D) = Ohms
Vdrop (AWG Wire Size ) = (Ohms)*(Amps) = Volts IF < Volts' Wire OK

NOTE:    Not with standing Table - 310-16 ( Allowance Ampacities of Insulated Conductors...)
In Normal Installations; Maximum are as follows for:
# 14 Cu wire     up to 15 A max.
# 12 Cu wire     up to 20 A max.
# 10 Cu wire     up to 30 A max.



CALCULATIONS:

For Electric Disconect/Sub Feed to Panel B ( @ Garage ) ( Panel A )
Electric Disconect/Sub Feed to Panel B    24 Kva
24000 va / 240 v    = 100 A
Req'd. 100 A over current Device
( NEC Table 310 - 16 ) 3 # 3 THHN Cu Wires ( 2 Hot, 1 Neutral )

Electric Disconnect / Sub Feed to Panel B 3 # 3 THHN Cu Wires
#3 THHN size    Area = 0.0973 sq.in. ( Table 5, 1995 NFPA )
( 3 ) * ( 0.0973) = 0.2919 sq.in.
(0.2919 ) / 40 % = 0.730 sq.in.    ( Table 4, 1995 NFPA; 2 + wires )
1 '' rigid metallic tubing area = 0.864 > 0.730    ( Table 4, 1995 NFPA )
1'' Trade Size Conductor = 3 # 3 THHN ( App. C, Table C1, 1999 NEC )
    USE 1 '' Rigid Metallic Tubing
    No NEED for Box size - Wires go directly to Sub Panel B

For Clothes Dryer ( @ Garage ) ( Panel A )
Clothes Dryer    6 Kva
6000 va / 240 v = 25 A
Req'd. 30 A over current Device
( NEC Table 310 - 16 ) 3 # 10 THHN Cu Wires ( 2 Hot, 1 Neutral )
( NEC Table 250 - 95 ) 1 # 10 THHN Cu Grounding Wire

Clothes Dryer     4 # 10 THHN Cu Wires
# 10 THHN size Area = 0.0211 sq.in.     (Table 5, 1995 NFPA)
[( 4 )*(0.0211 )] = 0.0844 sq.in.
( 0.0844 ) / 40 % = 0.211 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2.5 cu.in. )*( 4 ) = 10 cu.in.    ( Table 370 - 16 (b); # 10 = 2.5 cu.in. )
1/2 '' rigid metallic tubing area = 0.304 > 0.211     ( table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 5 # 10 THHN ( App. C, Table C1, 1999 NEC )
    USE 1/1 '' Rigid Metallic Tubing
    USE 4 x 1 1/4 Square Box



For Water Heater ( @ Garage ) ( Panel A )
Water Heater    5 Kva
5000 va / 240 v = 20.83 A
Req'd. 30 A over current Device
( NEC Table 310 - 16 ) 3 # 10 THHN Cu Wires ( 2 Hot, 1 Neutral )
( NEC Table 250 - 95 ) 1 # 10 THHN Cu Grounding Wire

Water Heater     4 # 10 Thhn Cu Wires
# 10 THHN size    Area = 0.0211 sq.in.    (Table 5, 1995 NFPA)
[(4)*(0.0211)] = 0.0844 sq.in.
(0.0844) / 40% = 0.211 sq.in.    (Table 4, 1995 NFPA; 2+wires)
(2.5 cu.in.)*(4) = 10 cu.in.       (Table 370-16 (b); #10=2.5 cu.in.)
1/2" rigid metallic tubing area = 0.304 > 0.211    (Table 4, 1995 NFPA)
1/2" Trade Size Conductor    = 5 #10 THHN (App.C, Table C1, 1999 NEC)
4 x 1 1/4 Square box = 18 cu.in. = 7 #10    (Table 370-16 (a); 1996 NEC)
        USE    1/2" Rigid Metallic Tubing
            USE    4 x 1 1/4 Square Box

For Range (@ Kitchen) (Panel B)
Range                                                    9 Kva
            9000va / 240v = 37.5A
           Req'd.50A over current Device
                        ( NEC Table 310-16 ) 3 #8 THHN Cu Wires (2 Hot, 1 Neutral)
                        ( NEC Table 250-95 ) 1 #10 THHN Cu Grounding Wire

Range                         3 #8 THHN Cu Wires + 1 #10 THHN Cu Wire
#8 THHN size            Area = 0.0366 sq.in.    (Table 5, 1995 NFPA)
#10 THHN size          Area = 0.0211 sq.in.   (Table 5, 1995 NFPA)
[(3)*( 0.0366 )] + [ (1) * ( 0.0211)] = 0.1309 sq.in.
( 0.1309 ) / 40% = 0.0327 sq.in.        (Table 4, 1995 NFPA; 2+wires)
[(3)*(3 cu.in)] + [(1)*(2.5 cu.in)] =11.5 cu.in.   (Table 370-16(b), 1996 NEC)
3/4" rigid metallic tubing area = 0.533 > 0.327    (Table 4, 1995 NFPA)
3/4" Trade Size Conductor    = 6 #8 THHN  (App. C, Table C1,1999 NEC)
4 x 1 1/4 Square box = 18.0 cu.in. = 6 38     (Table 370-16(a); 1996 NEC)
            USE    3/4" Rigid Metallic Tubing
            USE    4 x 1 1/4 Square Box



For Laundry ( Washing Machine)-( @ Garage ) ( Panel A )
Laundry / Washing Machine    1.5 Kva
    1500va / 120 v = 12.5 A
    Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 1 Hot, 1 Neutral )

Laundry / Washing Machine     2 # 12 thhn cu Wires
#  12 THHN size      Area = 0.0133 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
       USE    4 x 1 1/4 Square Box

For Refrigerator ( # 2 ) - ( @ Garage ) ( Panel A )
Refrigerator    1.5 Kva
    1500va / 120v = 12.5 A
    Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 1 Hot, 1 Neutral )

Refrigerator    2 # 12 thhn cu Wires
#  12 THHN size      Area = 0.0133 sq.in. ( Table 5, 1995 NFPA )
[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box



For Refrigerator ( # 1 ) - ( @ Kitchen ) ( Panel B )
Refrigerator    1.5 Kva
    1500va / 120v = 12.5 A
    Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 1 Hot, 1 Neutral )

Refrigerator    2 # 12 thhn cu Wires
#  12 THHN size      Area = 0.0133 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box

For Small Appliance ( # 1 & # 2 ) - ( @ Kitchen ) ( Panel B )
Small Appliance ( Each )    1.5 Kva
    1500va / 120v = 12.5 A
    Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 1 Hot, 1 Neutral )

Small Appliance ( Each )    2 # 12 THHN Cu Wires
#  12 THHN size      Area = 0.0133 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box



For Microwave - ( @ Kitchen ) ( Panel B )
Microwave     0.8 Kva
    800va / 120v = 6.67A
    Req'd. 15A over current Device
        ( NEC Table 310 - 16 ) 2 # 14 THHN Cu Wires ( 1 Hot, 1 Neutral )

Microwave    2 # 14 THHN Cu Wires
#  14 THHN size      Area = 0.0097 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0097 )] = 0.0194 sq.in.
( 0.0266 ) / 40 % = 0.0485 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2 cu.in. ) = 6 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 12 # 14 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 9 # 14     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box

For Garbage Disposal - ( @ Kitchen ) ( Panel B )
Garbage Disposal     0.8 Kva
    800va / 120v = 6.67 A
    Req'd. 15A over current Device
        ( NEC Table 310 - 16 ) 2 # 14 THHN Cu Wires ( 1 Hot, 1 Neutral )

Garbage Disposal 2 # 14 THHN Cu Wires
#  14 THHN size      Area = 0.0097 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0097 )] = 0.0194 sq.in.
( 0.0266 ) / 40 % = 0.0485 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2 cu.in. ) = 6 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 12 # 14 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 9 # 14     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box



For Dishwasher - ( @ Kitchen ) ( Panel B )
Dishwasher     1.0 Kva
    1000va / 120v = 8.33 A
 Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 1 Hot, 1 Neutral )

Dishwasher    2 # 12 THHN Cu Wires
#  12 THHN size      Area = 0.0133 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.   ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box

For Lights / Receptacles - ( Panel a & Panel B )
Lights / Receptacles     1.2 Kva
    1200va / 120v = 10.0 A
    Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 1 Hot, 1 Neutral )

Lights / Receptacles    2 # 12 THHN Cu Wires
#  12 THHN size      Area = 0.0133 sq.in.     ( Table 5, 1995 NFPA )
[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing
        USE    4 x 1 1/4 Square Box to FIRST Junction Box



For Sprinkler Pump - ( Panel A )
Sprinkler Pump     Single Phase, 1.5 hp, 240v
    Single Phase, 1.5 hp, 240v = 10.0 A ( Table 430 - 148, 1996 NEC )
    I = ( 125 % )*( 10 A ) = 12.5 A   ( Apply 125 % factor to determine I )
    Req'd. 20A over current Device
        ( NEC Table 310 - 16 ) 2 # 12 THHN Cu Wires ( 2 Hot )

To Determine if wires will carry power
Given:    Pump located @ 20 ' from panel
    Max. Voltage Drop < 3 %

# 12 Cu Wire = 2.05 ohm / Kft   ( Table 8, 1996 NEC )

Max. V drop = ( 240v )*( 3 % ) = 7.2v

p 12 ( Cu ) = [( 2.05 ) / 1000' ]*( 2 wire )*9 20' ) = 0.082 ohm
v 12 = 9 0.082 ohm )*( 10 A ) = 0.82v < 7.2    Wire OK

Sprinkler Pump    2 # 12 THHN Cu Wires
# 12 THHN size     Area = 0.0133 sq.in.  ( Table 5, 1995 NFPA )

[( 2 )*( 0.0133 )] = 0.0266 sq.in.
( 0.0266 ) / 40 % = 0.0665 sq.in.    ( Table 4, 1995 NFPA; 2+wires )
( 2 )*( 2.25 cu.in. ) = 4.5 cu.in.    ( Table 370 - 16 (b); 1996 NEC )
1/2 '' rigid metallic tubing area = 0.304 > 0.0665     ( Table 4, 1995 NFPA )
1/2 '' Trade Size Conductor = 9 # 12 THHN ( App. C, Table C1, 1999 NEC )
4 x 1 1/4 Square box = 18.0 cu.in. = 8 # 12     ( Table 370 -16(a); 1996 NEC )
        USE 1/2 '' Rigid Metallic Tubing to Junction Box
        USE    4 x 1 1/4 Square Box to  Junction Box
        USE 1/2 '' Liquid Tight Tubing ( < 6 ' ) to Motor



Table 1
Table 2
Single Phase Riser
Only at Main
Overhead Service
Typical 120v/240v Electrical Main Panel
Above Ground Minimum Clearance


RESIDENTIAL WIRING CODE ( NEC 1996 )

DEFINITIONS ( Article 100 ) :
Dwelling Unit-    Some place you can keep house, eat, cook & bathe (i.e.- has a bedroom, kitchen & living room )
Bathroom Area-    An area that has a sink outside of bathroom area (i.e.- Motel Room ), and still be consider a bathroom area.

Receptacles ( Sect. 210-52 )

General Rule ( 210-52 (a) )
Habitable Rooms ( Kitchen, living rooms, dining room, bedroom )
6 foot rule-     Receptacle outlets shall be installed so that no point along the floor line in any wall space is more than 6 feet ( measured horizontally ) from an outlet in that space

2 foot rule-     Including any wall space 2 ft. wide or greater
Door Wall- ( sliding glass doors ) Measurements start at end of fixed glass DO NOT measure across Door Ways

Exception     Baseboard heaters ( Sect. 424-9 ) DO NOT out a receptacle over an Electric baseboard heater UNLESS baseboard heater has electrical outlet that is an integrated part of the heater

Small Appliance Circuit ( Kitchen ) ( 210-52 (b) )
    Two ( 2 ) Separate circuits in Kitchen ( i.e.- two separate 20A Kitchen circuits; Excluding outlet for clock and gas range

    Exceptions ( 210-52 ( b ) ( 1 ) )
    One 15A circuit for refrigerator
    Switch receptacle for light @ Dinning Room

Kitchen Counter-tops ( 210-52 (c) )
    2 foot rule-    Receptacle outlet every 2 feet
                         DO NOT measure across sink
    1 foot rule-    1 foot wall (or wider) requires separate receptacle
    Counter Locations-    Receptacle CANNOT be 18" above countertop
                                      Receptacle CANNOT be in face-up position
                                              (i.e. neutral to the top)
                                      Receptacle CANNOT be > 12" below counter-top
                                      MUST HAVE- 1 receptacle @ peninsula/ island
                                                IF > 1' x 2'

    Exception (210-52 (c) (5)
    To put receptacle below counter-top ( < 12" );  MUST HAVE
    approval of city/county electrical inspector

Bathroom Area (210-52 (d) )
    Separate 20A circuit, GFCI protected (if more than one bathroom,
        they can be on the same circuit )
    One (1) Receptacle adjacent to EACH basin
        (i.e.- 2 basins; then 2 outlets)
    Receptacle CANNOT be in face-up position
        (i.e.- neutral to the top)

Laundry (210-52 (f) )
    One (1) 20A circuit

Basement / Garages (210-52 (g) )
    At least one GFCI protected circuit

Hallways (210-52 (h) )
    If hallway length > 10' ; One ( 1 ) outlet is required



GFCI Protection ( Sect. 210-8 (a) )

a. Bathrooms ALL receptacles must be GFCI protected
( including the ones in the light fixtures )

b. Garages ALL receptacles must be GFCI protected
Unless Not readily accessible ( i.e. - need ladder to get to it )
Except an appliance occupying a dedicated space, then single receptacle, NOT duplex ( i.e. -washer, freezer )

c. Outdoor  Receptacles ALL receptacles must be GFCI protected
Exception ( Art. 426 ) If receptacle not readily accessible and by ( Art. 426 ) GFP ( Ground Fault Protected )

d. Crawl Space ALL receptacles

e. Unfinished Basement At least one ( 1 ) receptacle must be GFCI protected when area is NOT meant as a living space

f. Kitchen Counter-top ALL receptacles meant to serve countertop surfaces must be GFCI protected ( above & below )

g. Wet Bar If area is > 6', Must be GFCI protected ( as in a bath basin )

Lights & Light Switches ( Sect. 210-70 ( a ) )
a.    To every habitable room
b.    3- Way @ stairways > 6 risers
c.    @ porches
d.    @ entrance to attic, crawl space, unfinished basement, garages

Closet Lights ( Article 410-8 )
Lights are permitted @ storage spaces IF:
a.    > 2 ft from wall
b.    > 1 ft from wall @ top
Incandescent Light 12'' clearance from fixture to storage space
Fluorescent Light / Recessed Incandescent Light
    6'' clearance from fixture to storage area/space
See Article 410-8 ( b ) & ( c ) Types of fixture

Recessed Fixtures ( Articles 410-65 & 410-66 )
a.    1/2'' Min. clearance between fixture & wood
b.    3'' Min. clearance between fixture and Fixture Junction Box, & Thermal Insulation



Outdoor Receptacles ( Article 410-57 ( b ) )
Types of Cover REQUIRED:
a. Total Cover ( new code )
b. Single Flap Cover ( old code )

Receptacle to be weather-proof While in Use    use Total Cover ( new )
    Exception     if outlet is likely NOT to be used while raining then use old type of cover ( Single Flap )

Fan Boxes ( Article 422-18 & 370-27 ( c ) )
    For Ceiling Paddle fans:    If box is MAIN support for fan, said junction box must be listed to be used for said use ( used for paddle fans )

Gas Furnace ( Article 422-7 )
    Must be on Separate Circuit

Disconnects ( Article 422-21 ( b ) )
    If appliance > 300 w, disconnect must be in sight of appliance or lockout at circuit breaker

Electric Range & Dryer ( 250-60 )
    Outlets changed from old NEC 1993 Code of 50 A, 125/250v 3 pole/3 wire to 50 A, 125/250v 4 pole/4 wire
(i.e.) 2 live wires + separate Neutral & Ground wires

General Lighting ( 220-4 ( a ) )
    General Lighting load = 3 w per sq.ft
    (i.e.- 1600 sq.ft. home = ( 1600 sq.ft. ) * ( 3 w/sq.ft. ) = 4,800w

( 210-21 ( b )( 3 ) )
    Max. load = 9 Amps ) * ( 80 % )    (i.e.)
Receptacle    Max. load    Circuit
    15 A            12 A        15 A or 20 A
    20 A            16 A        20 A ONLY

Clearance @ Service Panels ( 110-16 ( a ) )
120/240v    3' Minimum clearance in front of panel
30'' elbow room from side to side



CONDUITS

1. Maximum number of wires though pipes ( tubing ) dictated by code ( see NFPA - Table 4 : Dimensions & Percent Area of Conduit & Tubing ) Code : cannot use 100 % of area because of heating effect
Hence ( per Table # 4 )    2 + wires use 40 % of area

Use Table 4     Total Area ( 100 % ) of Pipe Percent Usage ( dictated by # of wires )
        Table 5    Approximate area of Conductors

Number of Wires/Conductors inside Pipe =
[ ( Total Area of Pipe ) * ( Percentage Usage )]/ ( Area of Wire/Conductor )

2. Conduits MUST be supported as per the following table
 
 
CONDUIT
   
SIZE ( in. )
METAL
NON-METAL
1/2''
10'
3'
3/4''
10'
3'
1''
12'
3'
1 1/2''
14'
5'
2''
16'
5'
3''
20'
6'
4''
20'
7'

3. Number of bends between outlets or fittings MUST NOT be greater than the equivalent of 4 - ( 90 ) bends or 360 total.

4. Connecting rigid conduit requires the use of a lock nut & bushing, firmly tightened to the pipe thread.

5. Flexible Metal Conduit-
if inside = Green field
if outside = Liquid Tight fitting
can be used for:
i. food waste disposal
ii. fluorescent lamps
iii. to motors
Is a flexible metal conduit is serving as an equipment ground return path, the total length shall NOT Exceed 6 ft.



6. Liquid Tight Flexible Metal Conduit (LTFMC )
a. LTFMC may be used as a grounding means if :
i. It is NOT over 1 1/4 '' trade size
ii. It is NOT over 6 ft. long
iii. is connected by fittings listed for grounding purposes
b. Minimum size = 1/2'' except 3/8'' when NOT longer than 6 ft.
c. When used as the grounding means the max. rated over current device is:
i. 20 A for 3/8'' & 1/2'' sizes
ii. 60 A for 3/4'' , 1'' and 1 1/4'' sizes
d. LTFMC may not be used as grounding means, in any size when:
i. longer than 6 ft.
ii. in any size > 1 1/2'', of any length
In such cases, a Bonding Jumper is required.