DAY 4 CHAPTER 3 CONDUCTOR SIZES,TYPES, ETC.

Continuous Load. A load where the maximum current is expected to continue for 3 hours or more. Continuous loads shall not exceed 80% of the rating of the Branch circuit

CIRCUIT BREAKERS ARE THE FINAL OVERCURRENT PROTECTION DEVICE

Branch Circuit. The circuit conductors between the finalovercurrent device protecting the circuit and the outlet(s).BRANCH CIRCUIT HAS 3 PARTS 1. CIRCUIT BREAKER 2. CONDUCTOR 3. DEVICES

THERE ARE 4 TYPES OF BRANCH CIRCUITS.1. SMALL APPLIANCE. 2. INDIVIDUAL 3. GENERAL PURPOSE 4. MULI-WIRE.

Branch Circuit, Individual. A branch circuit that supplies only one utilization equipment.

Branch Circuit, Appliance. A branch circuit that supplies energy to one or more outlets to which appliances are to be connected

Branch Circuit, General-Purpose. A branch circuit that supplies two or more receptacles or outlets for lighting and appliances.

Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.

TYPE NM CABLE MUST HAVE A BENDING RADIUS AT LEAST 5 TIMES THE DIAMETER OF THE CABLE.334.24

CONDUCTOR SIZE COLOR 14 AWG WHITE 12 AWG YELLOW 10 AWG ORANGE 8 AWG BLACK

COLOR CODE FOR NM-B CABLE 6-32: FIXING RECEPTELES TO DEVICE BOXES AND FACE PLATES ALSO FOR PLASTIC BOXES.

8-32: ATTACHING MUD RINGS TO BOXES

10-32: CEILING FAN BOXES,GROUND SCREWS

MAXIMUM OVERCURRENT FOR14AGW = 15AMPS12AGW = 20AMPS10AWG = 30AMPS

INDIVIDUAL BRANCH CIRCUIT HAS 1 HOT,1 NETURALMULTI-WIRE CIRCUITS HAVE 2 HOTS, 1 NETURAL

COLOR CODEWHITE IS RESERVED FOR NEUTRAL(GROUNDED CONDUCTOR)GREEN IS RESERVED FOR (GROUNDING CONDUCTOR), CAN ALSO BE BARE.BLACK, RED, ETC ARE HOT.(UNGROUNDED CONDUCTOR)

3 METALS ARE ALLOWED FOR CONDUCTORS 1.COPPER 2.ALUMINUM 3 COPPER CLAD ALUMINUM

FOR A 15A CIRCUIT.

FOR A 20A CIRCUIT.

Branch Circuit. The circuit conductors between the finalovercurrent device protecting the circuit and the outlet(s).

BRANCH CIRCUIT HAS 3 PARTS 1. CIRCUIT BREAKER 2. CONDUCTOR 3. DEVICES

Feeder. All circuit conductors between the service equipment,the source of a separately derived system, or otherpower supply source and the final branch-circuit overcurrentdevice.

Continuous Load. A load where the maximum current is expected to continue for 3 hours or more. Continuous loads shall not exceed 80% of the rating of theBranch circuit

Some loads in homes are continuous, such as electric water heaters, central electricheating, A/C. For these loads branch circuit rating, conductors, and the overcurrentdevices can’t be less then125% of the load.

Example: A/C with a name plate rating of 40amps, requires conductors and acircuit breaker with a rating of

ampsampsof

assametheisthis

ampsamps

4050%80

5025.140

CIRCUIT BREAKERS ARE THE FINAL OVERCURRENT PROTECTION DEVICE

THERE ARE 4 TYPES OF BRANCH CIRCUITS.

1. SMALL APPLIANCE.2. INDIVIDUAL3. GENERAL PURPOSE4. MULI-WIRE.

Branch Circuit, Appliance. A branch circuit that supplies energy to one or more outlets to which appliances are to be connected and that has no permanently connected luminaires that are not a part of an appliance.

Branch Circuit, Individual. A branch circuit that suppliesonly one utilization equipment.

Branch Circuit, General-Purpose. A branch circuit thatsupplies two or more receptacles or outlets for lighting andappliances.

SUPPLIES ONLY ONE PIECE OF EQUIPMENT

Branch Circuit, Multiwire. A branch circuit that consistsof two or more ungrounded conductors that have a voltagebetween them, and a grounded conductor that has equalvoltage between it and each ungrounded conductor of thecircuit and that is connected to the neutral or groundedconductor of the system.

MAXIMUM OVERCURRENT FOR14AGW = 15AMPS12AGW = 20AMPS10AWG = 30AMPS

INDIVIDUAL BRANCH CIRCUIT HAS 1 HOT,1 NETURAL

MULTI-WIRE CIRCUITS HAVE 2 HOTS, 1 NETURAL

COLOR CODEWHITE IS RESERVED FOR NEUTRAL(GROUNDED CONDUCTOR)GREEN IS RESERVED FOR (GROUNDING CONDUCTOR), CAN ALSO BE BARE.BLACK, RED, ETC ARE HOT.(UNGROUNDED CONDUCTOR)

3 METALS ARE ALLOWED FOR CONDUCTORS 1.COPPER 2.ALUMINUM 3 COPPER CLAD ALUMINUM

200.7grounded circuit conductor, (A)(1) A conductor with continuous white or gray covering(2) A conductor with three continuous white stripes onother than green insulation(3) A marking of white or gray color at the termination

250.119 Identification of Equipment Grounding Conductors. (B)shall be permitted to be bare, covered, or insulated. Individually covered or insulated equipment grounding conductors shall have a continuous outer finish that is either green or green with one or moreyellow stripes

Ungrounded conductor (hot) can be any colorOther than white, gray, green, or green withYellow strips. (C)

AMPACITY: CURRENT CARRYING CAPACITY OF A CONDUCTOR.

THE ALLOWED AMPACITY OF CONDUCTORS IN RESIDENCES IS FOUND IN TABLE 310.16. THESE AMPACITIES ARE SUBJECT TO CORRECTIONFACTORS FOR HIGH AMBIENT TEMPERATURES. THESE ARE FOUND ATTHE BOTTOM OF T 310.16. p70-148

T310.16 IS FOR THREE OR LESS CONDUCTORS IN A RACEWAY OR CABLE.

EXAMPLE: A 12AWG THHN COPPER CONDUCTOR AT 90°CIS RATED AT 30AMPS. IF THE AMBIENT TEMP. IS 56°C THECORRECTION FACTOR IS 0.71. USING THIS GIVES;

30AMPSX0.71=21.3AMPS, THIS IS THE DERATED USABLE AMPERAGE FOR THIS 12AWG CONDUCTOR.

IF THERE ARE MORE THEN 3 CONDUCTORS PRESENT A ADDITIONALCORRECTION FACTOR MUST BE APPILED AND IS FOUND IN TABLE310.15(B)(2)(a) p70-146

(2)

GIVEN THE SAME WIRE GAUGE SIZE, THE HIGHER ITS INSULATOR TEMPERATURE RATING IS, THE GREATER ITS AMPACITY WILL BE.

EXAMPLE: WHAT IS THE NUMBER OF RECEPTACLES ALLOWED FOR 15A AND 20A BRANCH CIRCUITS

HOW MUCH POWER CAN BE USED BY A 15A CIRCUIT?USING THE POWER EQUATION;

WP

VAP

IVP

1800

12015

APPLYING THE 80% AMPACITY CORRECTION FACTOR GIVES;

WW 144080.1800 WE ARE ALLOWED 180VA PER RECEPTACLE FROM 220.14(I) p70-59USING DAVID’S RULE OF THUMB TO FIND # OF RECEPTACLES PER BRANCH CIRCUIT;

SRECEPTACLENUMBER VAW

SRECEPTACLE 81801440

FOR A 15A CIRCUIT.

HOW MUCH POWER CAN BE USED BY A 20A CIRCUIT?USING THE POWER EQUATION;

WP

VAP

IVP

2400

12020

USING 80% AMPACITY CORRECTION FACTOR GIVES;

WW 192080.2400 GIVEN THAT 180VA PER RECEPTACLE FROM 220.14USING DAVID’S RULE OF THUMB TO FIND # OF RECEPTACLES PER BRANCH CIRCUIT;

SRECEPTACLENUMBER VAW

SRECEPTACLE 101801920

FOR A 20A CIRCUIT.

MAX. DISTANCE AROUND WALL CORNERS=12FT.

Fixed panels are counted as wall space Sliding panels are not wall space

One family Duplex

FISH TAPE(WIRE PULLERS) FOR PULLING WIRES THRU CONDUIT: COME IN LENGTHS FROM 25 TO100 FEET

VARIOUS LOOPS AVAILABLE AS FISH TAPE ENDS

WIRE LOOP AT END OF FISH TAPE

A NITROGEN POWERED GUN FOR PULLINGGUIDE ROPES THRU CONDUIT UP TO 100’

http://www.wikihow.com/Fish-Wires-Through-a-Conduit-or-PipeHow to Fish Wires Through a Conduit or Pipe