WIR

ES

& C

AB

LE

S:

WIR

ES

& C

AB

LE

S:

WIR

ES

& C

AB

LE

S:

WIR

ES

& C

AB

LE

S:

AP

PL

ICA

TIO

NS

ON

LO

W

AP

PL

ICA

TIO

NS

ON

LO

W

AP

PL

ICA

TIO

NS

ON

LO

W

AP

PL

ICA

TIO

NS

ON

LO

W

VO

LT

AG

E F

EE

DE

RS

&

VO

LT

AG

E F

EE

DE

RS

&

VO

LT

AG

E F

EE

DE

RS

&

VO

LT

AG

E F

EE

DE

RS

&

BR

AN

CH

CIR

CU

ITS

BR

AN

CH

CIR

CU

ITS

BR

AN

CH

CIR

CU

ITS

BR

AN

CH

CIR

CU

ITS

IIM

YT

HS

&F

AC

TS

INII

MY

TH

S&

FA

CT

SIN

IIM

YT

HS

&F

AC

TS

INII

MY

TH

S&

FA

CT

SIN

1

II: M

YT

HS

& F

AC

TS

IN

II: M

YT

HS

& F

AC

TS

IN

II: M

YT

HS

& F

AC

TS

IN

II: M

YT

HS

& F

AC

TS

IN

WIR

ES

& C

AB

LE

S W

IRE

S &

CA

BL

ES

WIR

ES

& C

AB

LE

S W

IRE

S &

CA

BL

ES

AP

PL

ICA

TIO

NA

PP

LIC

AT

ION

AP

PL

ICA

TIO

NA

PP

LIC

AT

ION

A T

YP

ICAL L

ARG

EA T

YP

ICAL L

ARG

EA T

YP

ICAL L

ARG

EA T

YP

ICAL L

ARG

ECO

RP

ORATE O

FFIC

E B

UIL

DIN

GCO

RP

ORATE O

FFIC

E B

UIL

DIN

GCO

RP

ORATE O

FFIC

E B

UIL

DIN

GCO

RP

ORATE O

FFIC

E B

UIL

DIN

G

MY

TH

S &

FA

CT

S M

YT

HS

& F

AC

TS

MY

TH

S &

FA

CT

S M

YT

HS

& F

AC

TS

MY

TH

S &

FA

CT

S M

YT

HS

& F

AC

TS

MY

TH

S &

FA

CT

S M

YT

HS

& F

AC

TS

INW

IRE

S&

INW

IRE

S&

INW

IRE

S&

INW

IRE

S&

INW

IRE

S&

INW

IRE

S&

INW

IRE

S&

INW

IRE

S&

22

IN W

IRE

S &

IN

WIR

ES

&

IN W

IRE

S &

IN

WIR

ES

&

IN W

IRE

S &

IN

WIR

ES

&

IN W

IRE

S &

IN

WIR

ES

&

CA

BL

ES

CA

BL

ES

CA

BL

ES

CA

BL

ES

CA

BL

ES

CA

BL

ES

CA

BL

ES

CA

BL

ES

AP

PL

ICA

TIO

NA

PP

LIC

AT

ION

AP

PL

ICA

TIO

NA

PP

LIC

AT

ION

AP

PL

ICA

TIO

NA

PP

LIC

AT

ION

AP

PL

ICA

TIO

NA

PP

LIC

AT

ION

THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) 60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed

MM

Siz

eA

ppro

xim

ate

AW

G S

ize

Am

paci

tyT

W60

deg

C

Am

paci

tyT

HW

75 d

eg C

Am

paci

tyT

HH

N90

deg

C

2.0

mm

214

1515

25

3.5

mm

212

2020

30

5.5

mm

210

3030

40

8.0

mm

28

4045

50

14m

m2

655

6570

33

14 m

m2

665

70

22 m

m2

470

8590

30 m

m2

290

110

115

38 m

m2

110

012

513

0

50 m

m2

1/0

120

145

150

60 m

m2

2/0

135

160

170

80 m

m2

3/0

160

195

205

100

mm

24/

018

522

025

5

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) 60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed60

0 V

OLTS

, S

trand

ed

MM

Siz

eA

ppro

xim

ate

AW

G S

ize

Am

paci

tyT

W60

deg

C

Am

paci

tyT

HW

75 d

eg C

Am

paci

tyT

HH

N90

deg

C

125

mm

225

0 M

CM

210

255

265

150

mm

230

0 M

CM

240

280

295

200

mm

240

0 M

CM

280

330

355

250

mm

250

0 M

CM

315

375

400

370

44

325

mm

265

0 M

CM

370

435

470

750

MC

M40

047

553

553

5

400

mm

280

0 M

CM

405

485

515

500

mm

210

00 M

CM

455

540

580

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

AM

PACIT

Y T

ABLE (Base

d o

n T

able

on A

VES

CO

pock

et b

ook)

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

Not m

ore

than 3

conduct

ors

in a

race

way o

r ca

ble

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

AM

PACIT

Y T

ABLE

(Lifte

d f

rom

(L

ifte

d f

rom

(L

ifte

d f

rom

(L

ifte

d f

rom

(L

ifte

d f

rom

(L

ifte

d f

rom

(L

ifte

d f

rom

(L

ifte

d f

rom

AV

ES

CO

pock

et

AV

ES

CO

pock

et

AV

ES

CO

pock

et

AV

ES

CO

pock

et

AV

ES

CO

pock

et

AV

ES

CO

pock

et

AV

ES

CO

pock

et

AV

ES

CO

pock

et

book)

book)

book)

book)

book)

book)

book)

book)

Note

: This

Table

is

Note

: This

Table

is

Note

: This

Table

is

Note

: This

Table

is

Note

: This

Table

is

Note

: This

Table

is

Note

: This

Table

is

Note

: This

Table

is

not qui

te iden

tica

l not qui

te iden

tica

l not qui

te iden

tica

l not qui

te iden

tica

l not qui

te iden

tica

l not qui

te iden

tica

l not qui

te iden

tica

l not qui

te iden

tica

l

55

with N

EC T

able

w

ith N

EC T

able

w

ith N

EC T

able

w

ith N

EC T

able

w

ith N

EC T

able

w

ith N

EC T

able

w

ith N

EC T

able

w

ith N

EC T

able

310

.16310

.16310

.16310

.16310

.16310

.16310

.16310

.16

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

BE C

AREFU

L IN

REFEREN

CIN

G

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

TABLES

ON

WIR

E &

CABLE

AM

PACIT

IES

.AM

PACIT

IES

.AM

PACIT

IES

.AM

PACIT

IES

.AM

PACIT

IES

.AM

PACIT

IES

.AM

PACIT

IES

.AM

PACIT

IES

.

66

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

BECAU

SE T

HEY A

RE N

OT A

CTU

ALLY

IDEN

TIC

AL…

IDEN

TIC

AL…

IDEN

TIC

AL…

IDEN

TIC

AL…

IDEN

TIC

AL…

IDEN

TIC

AL…

IDEN

TIC

AL…

IDEN

TIC

AL…

See

the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

S

ee the

diffe

renc

es o

n th

e ne

xt s

lide…

CO

MP

AR

ISO

N: N

OR

TH

AM

ER

ICA

N, P

HIL

IPP

INE

C

OM

PA

RIS

ON

: NO

RT

H A

ME

RIC

AN

, PH

ILIP

PIN

E

CO

MP

AR

ISO

N: N

OR

TH

AM

ER

ICA

N, P

HIL

IPP

INE

C

OM

PA

RIS

ON

: NO

RT

H A

ME

RIC

AN

, PH

ILIP

PIN

E

& E

UR

OP

EA

N M

AN

UF

AC

TU

RE

D C

AB

LE

S &

EU

RO

PE

AN

MA

NU

FA

CT

UR

ED

CA

BL

ES

& E

UR

OP

EA

N M

AN

UF

AC

TU

RE

D C

AB

LE

S &

EU

RO

PE

AN

MA

NU

FA

CT

UR

ED

CA

BL

ES

77

Jus

t cu

rious

…Jus

t cu

rious

…Jus

t cu

rious

…Jus

t cu

rious

…Jus

t cu

rious

…Jus

t cu

rious

…Jus

t cu

rious

…Jus

t cu

rious

…W

HIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

WHIC

H IS

THE M

ORE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE

EX

PEN

SIV

E W

IRE..? ..?..?..?..? ..?..?..?

88

TW

..?TW

..?TW

..?TW

..?TW

..?TW

..?TW

..?TW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

WHIC

H IS

THE S

UP

ERIO

R W

IRE?

TW

..?TW

..?TW

..?TW

..?TW

..?TW

..?TW

..?TW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THW

..?THHN

?THHN

?THHN

?THHN

?THHN

?THHN

?THHN

?THHN

?

99

THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?THHN

..?

Why

…?

Why

…?

Why

…?

Why

…?

Why

…?

Why

…?

Why

…?

Why

…?

DO

YO

U A

GREE T

HAT T

ODAY,

DO

YO

U A

GREE T

HAT T

ODAY,

DO

YO

U A

GREE T

HAT T

ODAY,

DO

YO

U A

GREE T

HAT T

ODAY, IN

IN

IN

IN

IN

IN

IN

IN

THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:THE P

HIL

IPP

INES

:

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

THE M

OS

T P

OP

ULAR B

UIL

DIN

G

WIR

ES

ARE T

HE T

HHN

?W

IRES

ARE T

HE T

HHN

?W

IRES

ARE T

HE T

HHN

?W

IRES

ARE T

HE T

HHN

?W

IRES

ARE T

HE T

HHN

?W

IRES

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HE T

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ION

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��F

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ere

sh

all

we

ba

se o

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loa

ds?

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m w

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re s

ha

ll w

e b

ase

ou

r lo

ad

s?

2424

��F

rom

wh

ere

sh

all

we

ba

se o

ur

sizi

ng

of

Fro

m w

he

re s

ha

ll w

e b

ase

ou

r si

zin

g o

f co

nd

uct

ors

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nd

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ors

?

��F

rom

wh

ere

sh

all

we

ba

se o

ur

OC

PD

?F

rom

wh

ere

sh

all

we

ba

se o

ur

OC

PD

?

2525

2626

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CH

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CH

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CH

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ITS

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CH

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ITS

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CH

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ITS

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CH

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2727

��T

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pa

city

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cir

cuit

T

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ot

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ust

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0- ---- ---1

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era

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is��

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e r

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ch c

ircu

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ra

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g o

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bra

nch

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cuit

is

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ch c

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ircu

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(NE

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- ---- ---3).

3).

3).

3).

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a).

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dt

ib

lth

dt

ib

l

4848

thre

e c

on

du

cto

rs in

a c

ab

le o

r ra

cew

ay

th

ree

co

nd

uct

ors

in a

ca

ble

or

race

wa

y

thre

e c

on

du

cto

rs in

a c

ab

le o

r ra

cew

ay

th

ree

co

nd

uct

ors

in a

ca

ble

or

race

wa

y

(No

te 8

to

Tab

les

31

0(N

ote

8 t

o T

able

s 3

10

(No

te 8

to

Tab

les

31

0(N

ote

8 t

o T

able

s 3

10

- ---16

th

rou

gh

31

01

6 t

hro

ug

h 3

10

16

th

rou

gh

31

01

6 t

hro

ug

h 3

10

- ---1

9).

19

).1

9).

19

).

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his

me

an

s a

ch

an

ge

in a

mp

aci

tie

s o

f T

his

me

an

s a

ch

an

ge

in a

mp

aci

tie

s o

f T

his

me

an

s a

ch

an

ge

in a

mp

aci

tie

s o

f T

his

me

an

s a

ch

an

ge

in a

mp

aci

tie

s o

f ci

rcu

it c

on

du

cto

rs.

circ

uit

co

nd

uct

ors

.ci

rcu

it c

on

du

cto

rs.

circ

uit

co

nd

uct

ors

.

TH

US

TH

ER

E A

RE

TW

O T

HIN

GS

TO

T

HU

S T

HE

RE

AR

E T

WO

TH

ING

S T

O

TH

US

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ER

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RE

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O T

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GS

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T

HU

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HE

RE

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ING

S T

O

CO

NSI

DE

R T

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ED

UC

E C

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CT

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C

ON

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ER

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RE

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CE

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ND

UC

TO

R

CO

NSI

DE

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ED

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CT

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C

ON

SID

ER

TH

AT

RE

DU

CE

CO

ND

UC

TO

R

AM

PA

CIT

IES…

AM

PA

CIT

IES…

AM

PA

CIT

IES…

AM

PA

CIT

IES…

TH

ESE

AR

E T

HE

FO

LL

OW

ING

:T

HE

SE A

RE

TH

E F

OL

LO

WIN

G:

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ESE

AR

E T

HE

FO

LL

OW

ING

:T

HE

SE A

RE

TH

E F

OL

LO

WIN

G:

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MP

AC

ITY

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RA

TIN

GD

UE

TO

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PA

CIT

YD

ER

AT

ING

DU

ET

OA

MP

AC

ITY

DE

RA

TIN

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UE

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AM

PA

CIT

YD

ER

AT

ING

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ET

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OR

ET

HA

NM

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ET

HA

NM

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ET

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NM

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MP

AC

ITY

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MP

AC

ITY

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RA

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MP

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MP

AC

ITY

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RA

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UE

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OR

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N

MO

RE

TH

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M

OR

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N

MO

RE

TH

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T

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) C

UR

RE

NT

CA

RR

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G C

ON

DU

CT

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S T

HR

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(3

) C

UR

RE

NT

CA

RR

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ON

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CT

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S T

HR

EE

(3

) C

UR

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NT

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RR

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CT

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HR

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NT

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RR

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G C

ON

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CT

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S IN

A C

ON

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IT O

R C

AB

LE

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CO

ND

UIT

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CA

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EIN

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ON

DU

IT O

R C

AB

LE

IN A

CO

ND

UIT

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CA

BL

E”,

”,

”,

”,

an

d…

an

d…

an

d…

an

d…

�C

orr

ect

ion

to

th

e c

on

du

cto

r C

orr

ect

ion

to

th

e c

on

du

cto

r C

orr

ect

ion

to

th

e c

on

du

cto

r C

orr

ect

ion

to

th

e c

on

du

cto

r a

mp

aci

tie

sa

mp

aci

tie

sa

mp

aci

tie

sa

mp

aci

tie

sw

he

n

wh

en

w

he

n

wh

en

in

sta

lle

d o

r o

pe

rate

d a

t te

mp

era

ture

s o

ve

r o

r in

sta

lle

d o

r o

pe

rate

d a

t te

mp

era

ture

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ve

r o

r in

sta

lle

d o

r o

pe

rate

d a

t te

mp

era

ture

s o

ve

r o

r in

sta

lle

d o

r o

pe

rate

d a

t te

mp

era

ture

s o

ve

r o

r u

nd

er

30

de

g C

am

bie

nt

un

de

r 3

0 d

eg

C a

mb

ien

tu

nd

er

30

de

g C

am

bie

nt

un

de

r 3

0 d

eg

C a

mb

ien

t.

THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) THERM

OP

LAS

TIC

WIR

E &

CABLES

(TW

, THW

, THHN

) 60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

60

0 V

OLTS

, S

trand

ed (N

EC T

able

310

.16)

MM

Siz

eA

ppro

xim

ate

AW

G S

ize

Am

paci

tyT

W60

deg

C

Am

paci

tyT

HW

75 d

eg C

Am

paci

tyT

HH

N90

deg

C

2.0

mm

2#

1420

2025

3.5

mm

2#

1225

2530

5.5

mm

2#

1030

3540

8.0

mm

2#

840

5055

14m

m2

#6

5565

75

5050

14 m

m2

# 6

6575

22 m

m2

# 4

7085

95

30 m

m2

# 2

9511

513

0

38 m

m2

# 1

110

130

150

50 m

m2

1/0

125

150

170

60 m

m2

2/0

145

175

195

80 m

m2

3/0

165

200

225

100

mm

24/

019

523

026

0

5151

Giv

en

: 6 #

12

TH

W in

a c

on

du

it a

t a

mb

ien

t G

ive

n: 6

# 1

2 T

HW

in a

co

nd

uit

at

am

bie

nt

Giv

en

: 6 #

12

TH

W in

a c

on

du

it a

t a

mb

ien

t G

ive

n: 6

# 1

2 T

HW

in a

co

nd

uit

at

am

bie

nt

tem

pe

ratu

re o

f 4

0 d

eg

Cte

mp

era

ture

of

40

de

g C

tem

pe

ratu

re o

f 4

0 d

eg

Cte

mp

era

ture

of

40

de

g C

Q1

: Wh

at

is t

he

eff

ect

ive

am

pa

city

of

the

Q

1: W

ha

t is

th

e e

ffe

ctiv

e a

mp

aci

ty o

f th

e

Q1

: Wh

at

is t

he

eff

ect

ive

am

pa

city

of

the

Q

1: W

ha

t is

th

e e

ffe

ctiv

e a

mp

aci

ty o

f th

e

con

du

cto

r?co

nd

uct

or?

con

du

cto

r?co

nd

uct

or?

5252

Q2

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

Q2

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

Q2

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

Q2

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

con

tin

uo

us

loa

d f

or

the

cir

cuit

?co

nti

nu

ou

s lo

ad

fo

r th

e c

ircu

it?

con

tin

uo

us

loa

d f

or

the

cir

cuit

?co

nti

nu

ou

s lo

ad

fo

r th

e c

ircu

it?

Q3

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

Q3

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

Q3

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

Q3

: Wh

at

is t

he

ma

xim

um

pe

rmis

sib

le

no

nn

on

no

nn

on

- ---co

nti

nu

ou

s lo

ad

fo

r th

e c

ircu

it?

con

tin

uo

us

loa

d f

or

the

cir

cuit

?co

nti

nu

ou

s lo

ad

fo

r th

e c

ircu

it?

con

tin

uo

us

loa

d f

or

the

cir

cuit

?

Am

pa

city

: # 1

2 T

HW

= 2

0 A

(N

EC

Ta

ble

31

0A

mp

aci

ty: #

12

TH

W =

20

A (

NE

C T

ab

le 3

10

Am

pa

city

: # 1

2 T

HW

= 2

0 A

(N

EC

Ta

ble

31

0A

mp

aci

ty: #

12

TH

W =

20

A (

NE

C T

ab

le 3

10

- ---16

)1

6)

16

)1

6)

Eff

ect

ive

Am

pa

city

: 20

A x

0.8

0 x

0.8

8 =

14

.08

AE

ffe

ctiv

e A

mp

aci

ty: 2

0 A

x 0

.80

x 0

.88

= 1

4.0

8 A

Eff

ect

ive

Am

pa

city

: 20

A x

0.8

0 x

0.8

8 =

14

.08

AE

ffe

ctiv

e A

mp

aci

ty: 2

0 A

x 0

.80

x 0

.88

= 1

4.0

8 A

Nt

Nt

Nt

Nt

5353

No

tes:

N

ote

s:

No

tes:

N

ote

s:

a)

De

rati

ng

Fa

cto

r o

f 0

.80

fo

r si

x c

on

du

cto

rs in

co

nd

uit

a)

De

rati

ng

Fa

cto

r o

f 0

.80

fo

r si

x c

on

du

cto

rs in

co

nd

uit

a)

De

rati

ng

Fa

cto

r o

f 0

.80

fo

r si

x c

on

du

cto

rs in

co

nd

uit

a)

De

rati

ng

Fa

cto

r o

f 0

.80

fo

r si

x c

on

du

cto

rs in

co

nd

uit

b)

Co

rre

ctio

n F

act

or

for

of

0.8

8 f

or

am

bie

nt

tem

p o

f 4

0 d

eg

Cb

) C

orr

ect

ion

Fa

cto

r fo

r o

f 0

.88

fo

r a

mb

ien

t te

mp

of

40

de

g C

b)

Co

rre

ctio

n F

act

or

for

of

0.8

8 f

or

am

bie

nt

tem

p o

f 4

0 d

eg

Cb

) C

orr

ect

ion

Fa

cto

r fo

r o

f 0

.88

fo

r a

mb

ien

t te

mp

of

40

de

g C

�M

ax

pe

rmis

sib

le lo

ad

(C

on

t. L

oa

d)

= 1

4.0

8 x

0.8

0 o

r 1

1.2

64

AM

ax

pe

rmis

sib

le lo

ad

(C

on

t. L

oa

d)

= 1

4.0

8 x

0.8

0 o

r 1

1.2

64

AM

ax

pe

rmis

sib

le lo

ad

(C

on

t. L

oa

d)

= 1

4.0

8 x

0.8

0 o

r 1

1.2

64

AM

ax

pe

rmis

sib

le lo

ad

(C

on

t. L

oa

d)

= 1

4.0

8 x

0.8

0 o

r 1

1.2

64

A

�M

ax

pe

rmis

sib

le lo

ad

(N

on

Ma

x p

erm

issi

ble

loa

d (

No

nM

ax

pe

rmis

sib

le lo

ad

(N

on

Ma

x p

erm

issi

ble

loa

d (

No

n- ---C

on

t. L

oa

d)

= 1

4.0

8 x

1 o

r 1

4.0

8 A

Co

nt.

Lo

ad

) =

14

.08

x 1

or

14

.08

AC

on

t. L

oa

d)

= 1

4.0

8 x

1 o

r 1

4.0

8 A

Co

nt.

Lo

ad

) =

14

.08

x 1

or

14

.08

A

Q4

: Q

4:

Q4

: Q

4: W

HE

RE

SH

AL

L W

E B

ASE

TH

E O

CP

D?

WH

ER

E S

HA

LL

WE

BA

SE T

HE

OC

PD

?W

HE

RE

SH

AL

L W

E B

ASE

TH

E O

CP

D?

WH

ER

E S

HA

LL

WE

BA

SE T

HE

OC

PD

?

a)

a)

a)

a)

Pu

bli

she

d

Pu

bli

she

d

Pu

bli

she

d

Pu

bli

she

d A

mp

aci

tyA

mp

aci

tyA

mp

aci

tyA

mp

aci

tyo

f #

12

AW

G w

hic

h is

20

A?

of

#1

2 A

WG

wh

ich

is 2

0 A

? o

f #

12

AW

G w

hic

h is

20

A?

of

#1

2 A

WG

wh

ich

is 2

0 A

?

b)

Th

e ‘E

ffe

ctiv

e’

b)

Th

e ‘E

ffe

ctiv

e’

b)

Th

e ‘E

ffe

ctiv

e’

b)

Th

e ‘E

ffe

ctiv

e’ A

mp

aci

tyA

mp

aci

tyA

mp

aci

tyA

mp

aci

tyo

f #

12

AW

G w

hic

h is

14

.08

A?

of

#1

2 A

WG

wh

ich

is1

4.0

8 A

?o

f #

12

AW

G w

hic

h is

14

.08

A?

of

#1

2 A

WG

wh

ich

is1

4.0

8 A

?

5454

c) T

he

Ma

xim

um

Pe

rmis

sib

le L

oa

d w

hic

h is

11

.26

4 A

?c)

Th

e M

ax

imu

m P

erm

issi

ble

Lo

ad

wh

ich

is1

1.2

64

A?

c) T

he

Ma

xim

um

Pe

rmis

sib

le L

oa

d w

hic

h is

11

.26

4 A

?c)

Th

e M

ax

imu

m P

erm

issi

ble

Lo

ad

wh

ich

is1

1.2

64

A?

Q5

: WH

AT

WIL

L B

E T

HE

SIZ

E O

F T

HE

Q

5: W

HA

T W

ILL

BE

TH

E S

IZE

OF

TH

E

Q5

: WH

AT

WIL

L B

E T

HE

SIZ

E O

F T

HE

Q

5: W

HA

T W

ILL

BE

TH

E S

IZE

OF

TH

E

BR

AN

CH

CIR

CU

IT O

CP

D?

BR

AN

CH

CIR

CU

IT O

CP

D?

BR

AN

CH

CIR

CU

IT O

CP

D?

BR

AN

CH

CIR

CU

IT O

CP

D?

WH

AT

WIL

L B

E T

HE

SIZ

E O

F T

HE

BR

AN

CH

W

HA

T W

ILL

BE

TH

E S

IZE

OF

TH

E B

RA

NC

H

WH

AT

WIL

L B

E T

HE

SIZ

E O

F T

HE

BR

AN

CH

W

HA

T W

ILL

BE

TH

E S

IZE

OF

TH

E B

RA

NC

H

CIR

CU

IT B

RE

AK

ER

OR

FU

SE?

CIR

CU

IT B

RE

AK

ER

OR

FU

SE?

CIR

CU

IT B

RE

AK

ER

OR

FU

SE?

CIR

CU

IT B

RE

AK

ER

OR

FU

SE?

An

swe

r is

: 15

AA

nsw

er

is: 1

5 A

An

swe

r is

: 15

AA

nsw

er

is: 1

5 A

Be

cau

se o

f th

e m

an

da

tory

ma

tch

of

the

B

eca

use

of

the

ma

nd

ato

ry m

atc

h o

f th

e

Be

cau

se o

f th

e m

an

da

tory

ma

tch

of

the

B

eca

use

of

the

ma

nd

ato

ry m

atc

h o

f th

e

OC

PD

wit

h r

esp

ect

to

th

e a

mp

aci

ty o

f th

e

OC

PD

wit

h r

esp

ect

to

th

e a

mp

aci

ty o

f th

e

OC

PD

wit

h r

esp

ect

to

th

e a

mp

aci

ty o

f th

e

OC

PD

wit

h r

esp

ect

to

th

e a

mp

aci

ty o

f th

e

5555

con

du

cto

r!co

nd

uct

or!

con

du

cto

r!co

nd

uct

or!

No

te t

ha

t in

th

is c

ase

, th

e e

ffe

ctiv

e a

mp

aci

ty

No

te t

ha

t in

th

is c

ase

, th

e e

ffe

ctiv

e a

mp

aci

ty

No

te t

ha

t in

th

is c

ase

, th

e e

ffe

ctiv

e a

mp

aci

ty

No

te t

ha

t in

th

is c

ase

, th

e e

ffe

ctiv

e a

mp

aci

ty

of

the

# 1

2 c

on

du

cto

r h

ap

pe

ns

to b

e d

era

ted

o

f th

e #

12

co

nd

uct

or

ha

pp

en

s to

be

de

rate

d

of

the

# 1

2 c

on

du

cto

r h

ap

pe

ns

to b

e d

era

ted

o

f th

e #

12

co

nd

uct

or

ha

pp

en

s to

be

de

rate

d

at

14

.08

A o

nly

.a

t 1

4.0

8 A

on

ly.

at

14

.08

A o

nly

.a

t 1

4.0

8 A

on

ly.

IF T

HE

20

A O

CP

D F

OR

A #

12

IF

TH

E 2

0 A

OC

PD

FO

R A

#1

2

IF T

HE

20

A O

CP

D F

OR

A #

12

IF

TH

E 2

0 A

OC

PD

FO

R A

#1

2

AW

G C

ON

DU

CT

OR

IN

A

WG

CO

ND

UC

TO

R I

N

AW

G C

ON

DU

CT

OR

IN

A

WG

CO

ND

UC

TO

R I

N

PR

EV

IOU

S E

XE

RC

ISE

IS

TO

BE

P

RE

VIO

US

EX

ER

CIS

E I

S T

O B

E

PR

EV

IOU

S E

XE

RC

ISE

IS

TO

BE

P

RE

VIO

US

EX

ER

CIS

E I

S T

O B

E

RE

TA

INE

D…

RE

TA

INE

D…

RE

TA

INE

D…

RE

TA

INE

D…

5656

TH

E D

ER

AT

ING

&

TH

E D

ER

AT

ING

&

TH

E D

ER

AT

ING

&

TH

E D

ER

AT

ING

&

CO

RR

EC

TIO

N F

AC

TO

RS

WIL

L

CO

RR

EC

TIO

N F

AC

TO

RS

WIL

L

CO

RR

EC

TIO

N F

AC

TO

RS

WIL

L

CO

RR

EC

TIO

N F

AC

TO

RS

WIL

L

MA

KE

TH

E C

IRC

UIT

MA

KE

TH

E C

IRC

UIT

MA

KE

TH

E C

IRC

UIT

MA

KE

TH

E C

IRC

UIT

CO

ND

UC

TO

RS

BIG

GE

R…

!C

ON

DU

CT

OR

S B

IGG

ER

…!

CO

ND

UC

TO

RS

BIG

GE

R…

!C

ON

DU

CT

OR

S B

IGG

ER

…!

If y

ou

de

cid

e 2

0 A

OC

PD

, th

en

If

yo

u d

eci

de

20

A O

CP

D, t

he

n

If y

ou

de

cid

e 2

0 A

OC

PD

, th

en

If

yo

u d

eci

de

20

A O

CP

D, t

he

n

the

siz

e o

f th

e c

on

du

cto

rs s

ha

ll

the

siz

e o

f th

e c

on

du

cto

rs s

ha

ll

the

siz

e o

f th

e c

on

du

cto

rs s

ha

ll

the

siz

e o

f th

e c

on

du

cto

rs s

ha

ll

be

:b

e:

be

:b

e:

#1

0T

HW

#1

0T

HW

#1

0T

HW

#1

0T

HW

5757

# 1

0 T

HW

# 1

0 T

HW

# 1

0 T

HW

# 1

0 T

HW

No

t #

12

TH

W!

No

t #

12

TH

W!

No

t #

12

TH

W!

No

t #

12

TH

W!

ASS

UM

ING

TH

AT

TH

E D

ER

AT

ING

A

SSU

MIN

G T

HA

T T

HE

DE

RA

TIN

G

ASS

UM

ING

TH

AT

TH

E D

ER

AT

ING

A

SSU

MIN

G T

HA

T T

HE

DE

RA

TIN

G

& C

OR

RE

CT

ION

FA

CT

OR

S H

AV

E

& C

OR

RE

CT

ION

FA

CT

OR

S H

AV

E

& C

OR

RE

CT

ION

FA

CT

OR

S H

AV

E

& C

OR

RE

CT

ION

FA

CT

OR

S H

AV

E

AL

RE

AD

Y B

EE

N C

ON

SID

ER

ED

,A

LR

EA

DY

BE

EN

CO

NSI

DE

RE

D,

AL

RE

AD

Y B

EE

N C

ON

SID

ER

ED

,A

LR

EA

DY

BE

EN

CO

NSI

DE

RE

D,

Q: I

S SI

ZIN

G O

F C

IRC

UIT

S Q

: IS

SIZ

ING

OF

CIR

CU

ITS

Q: I

S SI

ZIN

G O

F C

IRC

UIT

S Q

: IS

SIZ

ING

OF

CIR

CU

ITS

FIN

ISH

ED

…?

FIN

ISH

ED

…?

FIN

ISH

ED

…?

FIN

ISH

ED

…?

5858

FIN

ISH

ED

…?

FIN

ISH

ED

…?

FIN

ISH

ED

…?

FIN

ISH

ED

…?

NO

TQ

UIT

E…

!

5959

NO

T Q

UIT

E…

!

BE

CA

USE

, B

EC

AU

SE,

BE

CA

USE

, B

EC

AU

SE,

CO

ND

UC

TO

RS

MU

STM

AT

CH

CO

ND

UC

TO

RS

MU

STM

AT

CH

CO

ND

UC

TO

RS

MU

STM

AT

CH

CO

ND

UC

TO

RS

MU

STM

AT

CH

6060

CO

ND

UC

TO

RS

MU

ST M

AT

CH

C

ON

DU

CT

OR

S M

UST

MA

TC

H

CO

ND

UC

TO

RS

MU

ST M

AT

CH

C

ON

DU

CT

OR

S M

UST

MA

TC

H

TH

E T

EM

PE

RA

TU

RE

RA

TIN

GS

TH

E T

EM

PE

RA

TU

RE

RA

TIN

GS

TH

E T

EM

PE

RA

TU

RE

RA

TIN

GS

TH

E T

EM

PE

RA

TU

RE

RA

TIN

GS

OF

CIR

CU

IT D

EV

ICE

S…O

F C

IRC

UIT

DE

VIC

ES…

OF

CIR

CU

IT D

EV

ICE

S…O

F C

IRC

UIT

DE

VIC

ES…

Wir

ing

Con

duct

or A

mpa

city

to

Tem

pera

ture

Rat

ing

�M

old

ed

-case

cir

cuit

bre

akers

are

mark

ed

wit

h

bo

th t

he s

ize

an

d in

sula

tion

tem

pera

ture

rat

ing 6161

bo

tt

es

ea

dsu

ato

tepe

atu

eat

g(e

.g.,

#2

Cu

, 6

0/

75

°C)

of

the c

on

du

cto

rsap

pro

ved

fo

r u

se w

ith

th

e c

ircu

it b

reaker.

�Pr

oper

ly s

ized

con

duct

ors

allo

w t

he

circ

uit

bre

aker

therm

al-

sen

sin

g e

lem

en

ts t

o

matc

h t

he c

on

du

cto

r th

erm

al

pro

tect

ion

req

uir

em

en

ts.

SIZ

ING

CO

ND

UC

TO

RS

BA

SE

D

ON

TEM

PER

ATU

RE R

ATIN

G 6262

Whe

n se

lect

ing

a co

nduc

tor

for

a ci

rcui

t, o

ne h

as t

o be

se

lect

ed t

o ac

com

mod

ate

the

tem

pera

ture

ter

min

atio

n ra

ting

rul

esou

tlin

ed in

NEC

110

-14(

c). T

his

incl

udes

th

e co

mpa

tibi

lity

of a

con

duct

or t

ype

as t

o th

e O

CPD

’s

& o

ther

dev

ices

the

con

duct

or t

erm

inat

es in

side

an

encl

osur

e.

SIZ

ING

CO

ND

UC

TO

RS

BA

SED

ON

TEM

PER

ATU

RE R

ATIN

G

�U

nd

erw

rite

r La

bo

rato

ries

Inc.

(U

L) s

tan

dard

s re

qu

ire t

hat

mo

lded

-case

cir

cuit

bre

akers

rate

d

at

12

5 a

mp

ere

s o

r le

ss b

e m

ark

ed

wit

h t

he

con

du

cto

r in

sula

tio

n-t

em

pera

ture

rati

ng

.

�Th

e w

ire t

em

pera

ture

rati

ng

is

dete

rmin

ed

by 6363

test

ing

th

e c

ircu

it b

reaker

un

der

full-l

oad

cu

rren

t w

ith

co

nd

uct

ors

siz

ed

fo

r th

e

ap

pro

pri

ate

tem

pera

ture

rati

ng

, 6

0°C

or

75

°C.

SIZ

ING

CO

ND

UC

TO

RS

BA

SED

ON

TEM

PER

ATU

RE R

ATIN

G

�C

ondu

ctor

s w

ith

90°C

rat

ed in

sula

tion

(T

HH

N)

can

be u

sed

on c

ircu

it b

reak

ers

rate

d fo

r 60

°C

or 7

5°C

wir

ing

only

if t

heir

siz

e is

bas

ed o

n th

e am

paci

ty o

f th

e lo

wer

tem

pera

ture

-rat

ed w

ire.

�If

th90

°C(T

HH

N)

ii

tb

6464

�If

the

90°

C (

TH

HN

) w

ire

size

wer

e to

be

sele

cted

bas

ed o

n th

e am

paci

ty a

llow

ed in

the

90

°C c

olum

n of

the

Am

paci

ty T

able

, the

sm

alle

r re

sult

ing

wir

e si

ze w

ould

gen

erat

e ad

diti

onal

he

at a

t th

e ci

rcui

t br

eake

r te

rmin

als

and

poss

ibly

cau

se n

uisa

nce

trip

ping

.

SIZ

ING

CO

ND

UC

TO

RS

BA

SED

ON

TEM

PER

ATU

RE R

ATIN

G

6565

NEC

Tab

le 3

10

.16

6666

NEC

Tab

le 3

10

.16

6767

IMP

OR

TAN

T!!!

PO

INT

1:Fo

r de

vice

or

equi

pmen

t te

rmin

als

rate

d 10

0 A

or

less

,wir

e si

zes

shal

l be

base

d on

th

e‘6

0de

gC

SIZ

ING

CO

ND

UC

TO

RS

B

AS

ED

ON

TEM

PER

ATU

RE R

ATIN

G

6868

the

60 d

eg C

te

mpe

ratu

re r

atin

g’lis

ted

in N

EC A

mpa

city

Ta

ble

310-

16.

NEC

Tab

le 3

10

.16

6969

SIZ

ING

C

ON

DU

CTO

RS

B

AS

ED

ON

TEM

PER

ATU

RE

RA

TIN

G

PO

INT

2:

Cir

cuit

s ov

er 1

00A

[NE

C

Sec

. 110

-14(

c)(2

)]:

Unl

ess

the

term

inal

s ar

e m

arke

d ot

herw

ise,

i

t/d

i

7070

equi

pmen

t/ d

evic

e

term

inal

s ra

ted

over

100

A

shal

l be

size

d ac

cord

ing

to

the

‘75

deg

C t

empe

ratu

re

rati

ng’l

iste

d in

NE

C T

able

31

0-16

.

SIZ

ING

CO

ND

UC

TO

RS

BA

SE

D O

N

TEM

PER

ATU

RE R

ATIN

G

Thi

s is

now

the

cat

ch!

Nin

ety

deg

C r

ated

con

duct

or a

mpa

citi

es li

ke t

he

THH

N’s

can

not

be

typi

cally

use

d fo

r si

zing

cir

cuit

co

nduc

tors

.How

ever

, its

rat

ing

only

com

es in

to p

lay

PO

INT

3:

Wha

t th

en is

the

pur

pose

of

90

deg

C w

ire

if w

e ca

nnot

use

its

high

er a

mpa

city

?

7171

whe

n ad

just

ing

cond

ucto

r am

paci

ty fo

r el

evat

ed

ambi

ent

tem

pera

ture

(cor

rect

ion

due

to t

empe

ratu

re)o

r w

hen

bund

ling

mor

e th

an t

hree

cur

rent

-car

ryin

g co

nduc

tors

tog

ethe

r (d

erat

ing)

.

The

adv

anta

ge o

f 90

deg

C w

ire

(TH

HN

) is

tha

t it

can

ke

ep t

he d

esig

ner

from

usi

ng a

larg

er w

ire

(whe

n am

paci

ty a

djus

tmen

ts a

re n

eede

d),w

hich

req

uire

larg

er

cond

uits

& r

acew

ays,

gre

ater

labo

r &

incr

ease

d m

ater

ial c

osts

.

7272

TO R

EV

IEW

:

�Im

port

ant

in t

he e

lect

rica

l & t

herm

al r

elat

ions

hip

for

circ

uit

com

pone

nts

are

the

cond

ucto

r si

ze, r

ated

am

paci

ty, t

he in

sula

tion

tem

pera

ture

rat

ing

and

the

perm

issi

ble

conn

ecto

r de

vice

tem

pera

ture

lim

its.

�Fo

r in

stan

ce, t

he a

mpa

city

for

a c

ondu

ctor

wit

h 90

°C

7373

insu

lati

on (

TH

HN

) is

gen

eral

ly g

reat

er t

han

of a

con

duct

or

of t

he s

ame

size

but

wit

h 60

°C (

TW

) in

sula

tion

.

�H

owev

er, t

he g

reat

er a

mpa

city

of

a T

HH

N c

ondu

ctor

wit

h 90

°C in

sula

tion

is n

ot a

lway

s pe

rmit

ted

to b

e us

ed d

ue t

o lim

itat

ions

of

the

term

inal

tem

pera

ture

rat

ing

and/

or t

he

requ

irem

ents

of

the

NE

C®

. (R

efer

ence

110

.14

in t

he N

EC

®

for

spec

ific

req

uire

men

ts.)

How

ever

, th

ere

are

som

e si

mple

rul

es to

How

ever

, th

ere

are

som

e si

mple

rul

es to

How

ever

, th

ere

are

som

e si

mple

rul

es to

How

ever

, th

ere

are

som

e si

mple

rul

es to

follo

w f

or ci

rcui

ts o

f 10

0A a

nd les

s.

follo

w f

or ci

rcui

ts o

f 10

0A a

nd les

s.

follo

w f

or ci

rcui

ts o

f 10

0A a

nd les

s.

follo

w f

or ci

rcui

ts o

f 10

0A a

nd les

s.

The

se s

imple

rul

es g

ener

ally

sho

uld b

e The

se s

imple

rul

es g

ener

ally

sho

uld b

e The

se s

imple

rul

es g

ener

ally

sho

uld b

e The

se s

imple

rul

es g

ener

ally

sho

uld b

e fo

llow

ed b

ecaus

e th

ese

are

the

norm

s fo

r th

e fo

llow

ed b

ecaus

e th

ese

are

the

norm

s fo

r th

e fo

llow

ed b

ecaus

e th

ese

are

the

norm

s fo

r th

e fo

llow

ed b

ecaus

e th

ese

are

the

norm

s fo

r th

e dev

ice

com

pone

nt p

roduc

t st

and

ard

s and

dev

ice

com

pone

nt p

roduc

t st

and

ard

s and

dev

ice

com

pone

nt p

roduc

t st

and

ard

s and

dev

ice

com

pone

nt p

roduc

t st

and

ard

s and

7474

pp

pp

pp

pp

per

form

anc

e ev

alu

ation

to the

se s

tand

ard

s per

form

anc

e ev

alu

ation

to the

se s

tand

ard

s per

form

anc

e ev

alu

ation

to the

se s

tand

ard

s per

form

anc

e ev

alu

ation

to the

se s

tand

ard

s fo

r fu

ses,

blo

cks,

dis

conn

ects

, ho

lder

s, c

ircu

it

for fu

ses,

blo

cks,

dis

conn

ects

, ho

lder

s, c

ircu

it

for fu

ses,

blo

cks,

dis

conn

ects

, ho

lder

s, c

ircu

it

for fu

ses,

blo

cks,

dis

conn

ects

, ho

lder

s, c

ircu

it

bre

aker

s, e

tc.

bre

aker

s, e

tc.

bre

aker

s, e

tc.

bre

aker

s, e

tc.

Sim

ple rul

es f

or 10

0 a

mps

and

les

sS

imple rul

es f

or 10

0 a

mps

and

les

sS

imple rul

es f

or 10

0 a

mps

and

les

sS

imple rul

es f

or 10

0 a

mps

and

les

s: :::

1. U

se

1. U

se

1. U

se

1. U

se 6

060

60

60

° °°°C rate

d c

ond

ucto

rsC rate

d c

ond

ucto

rsC rate

d c

ond

ucto

rsC rate

d c

ond

ucto

rs[110

.14(C

)(1)(a

)(1)].

Thi

s [110

.14(C

)(1)(a

)(1)].

Thi

s [110

.14(C

)(1)(a

)(1)].

Thi

s [110

.14(C

)(1)(a

)(1)].

Thi

s ass

umes

all

term

inations

are

rate

d f

or 60

ass

umes

all

term

inations

are

rate

d f

or 60

ass

umes

all

term

inations

are

rate

d f

or 60

ass

umes

all

term

inations

are

rate

d f

or 60

° °°°C rate

d

C rate

d

C rate

d

C rate

d

cond

ucto

rs.

cond

ucto

rs.

cond

ucto

rs.

cond

ucto

rs.

2. Hig

her te

mper

atu

re rate

d c

ond

ucto

rs c

an

be

used

, 2

. Hig

her te

mper

atu

re rate

d c

ond

ucto

rs c

an

be

used

, 2

. Hig

her te

mper

atu

re rate

d c

ond

ucto

rs c

an

be

used

, 2

. Hig

her te

mper

atu

re rate

d c

ond

ucto

rs c

an

be

used

,

7575

but

the

but

the

but

the

but

the

am

paci

ty o

f th

ese

cond

ucto

rs m

ust be

as

if

am

paci

ty o

f th

ese

cond

ucto

rs m

ust be

as

if

am

paci

ty o

f th

ese

cond

ucto

rs m

ust be

as

if

am

paci

ty o

f th

ese

cond

ucto

rs m

ust be

as

if

they

are

60

they

are

60

they

are

60

they

are

60

° °°°C rate

d c

ond

ucto

rsC rate

d c

ond

ucto

rsC rate

d c

ond

ucto

rsC rate

d c

ond

ucto

rs. . . .

In o

ther

word

s, e

ven

if a

90

In o

ther

word

s, e

ven

if a

90

In o

ther

word

s, e

ven

if a

90

In o

ther

word

s, e

ven

if a

90

° °°°C T

HHN

cond

ucto

r is

C T

HHN

cond

ucto

r is

C T

HHN

cond

ucto

r is

C T

HHN

cond

ucto

r is

us

ed, it h

as

to b

e ra

ted f

or am

paci

ty a

s if it w

ere

a

used

, it h

as

to b

e ra

ted f

or am

paci

ty a

s if it w

ere

a

used

, it h

as

to b

e ra

ted f

or am

paci

ty a

s if it w

ere

a

used

, it h

as

to b

e ra

ted f

or am

paci

ty a

s if it w

ere

a

60

60

60

60

° °°°C c

ond

ucto

r [110

.14(C

)(1)(a

)(2

)]..

C c

ond

ucto

r [110

.14(C

)(1)(a

)(2

)]..

C c

ond

ucto

r [110

.14(C

)(1)(a

)(2

)]..

C c

ond

ucto

r [110

.14(C

)(1)(a

)(2

)]..

For

inst

ance

, ass

ume

an a

mpa

city

of

60A

is n

eede

d in

a c

ircu

it

that

has

ter

min

atio

ns t

hat

are

rate

d fo

r 60

°C c

ondu

ctor

s. I

f a

90°C

con

duct

or is

to

be u

sed,

wha

t is

the

min

imum

con

duct

or

size

req

uire

d?

7676

Th

e a

nsw

er

is 4

AW

G, 9

0°C

con

duct

or.

A 6

AW

G,

90

°C c

on

du

cto

r h

as

an

am

paci

ty o

f 7

5 a

mp

s p

er

(NEC

® T

ab

le 3

10

.16

); b

ut

this

am

paci

ty c

an

no

t b

e u

sed

fo

r a 6

0°C

term

inati

on

.

For

this

cir

cuit

, if

a 9

0°C

, 6

AW

G c

on

du

cto

r is

eva

luate

d,

the

am

paci

ty o

f th

is c

on

du

cto

r m

ust

be a

cco

rdin

g t

o t

he 6

0°C

co

nd

uct

or

am

paci

ty,

wh

ich

is

55

A.

(Am

paci

ties

are

fro

m N

EC

®

Tab

le 3

10

.16

.)

3. C

ondu

ctor

s w

ith

high

er t

empe

ratu

re r

atin

gs

can

be u

sed

at t

heir

rat

ed a

mpa

citi

es if

the

te

rmin

atio

ns o

f th

e ci

rcui

t de

vice

s ar

e ra

ted

for

the

high

er t

empe

ratu

re r

ated

con

duct

or

[110

.14(

C)(

1)(a

)(3)

].

7777

How

ever

, the

indu

stry

nor

m is

tha

t m

ost

devi

ces

rate

d 10

0A o

r le

ss, s

uch

as b

lock

s,

disc

onne

cts

and

circ

uit

brea

kers

, hav

e 60

°C

or 7

5°C

rat

ed t

erm

inat

ions

.

4. F

or m

otor

s w

ith

desi

gn le

tter

s B

, C o

r D

, co

nduc

tors

wit

h in

sula

tion

rat

ing

of 7

5°C

of

high

er a

re p

erm

itte

d as

long

as

the

ampa

city

of

the

con

duct

ors

is n

ot g

reat

er t

han

the

75°C

rat

ing

[110

.14(

C)(

1)(a

)(4)

].

7878

5. I

f a

cond

ucto

r is

run

bet

wee

n tw

o de

vice

s th

at h

ave

term

inal

s ra

ted

at t

wo

diff

eren

t te

mpe

ratu

res,

the

rul

es a

bove

mus

t be

ob

serv

ed t

hat

corr

elat

e to

the

ter

min

al w

ith

the

low

est

tem

pera

ture

rat

ing .

For ci

rcui

ts

For ci

rcui

ts

For ci

rcui

ts

For ci

rcui

ts g

reate

r th

an

gre

ate

r th

an

gre

ate

r th

an

gre

ate

r th

an

100

A10

0A

100

A10

0A, us

e co

nduc

tors

with

, us

e co

nduc

tors

with

, us

e co

nduc

tors

with

, us

e co

nduc

tors

with

at least

a

at least

a

at least

a

at least

a 7

575

75

75° °°°C

ins

ulation

C ins

ulation

C ins

ulation

C ins

ulation

7979

rating

at th

eir 75

rating

at th

eir 75

rating

at th

eir 75

rating

at th

eir 75° °°°C

C

C

C

am

paci

ty rating

am

paci

ty rating

am

paci

ty rating

am

paci

ty rating

. ...

So w

hy w

oul

d a

nyone

eve

r w

ant

to u

se a

cond

ucto

r S

o w

hy w

oul

d a

nyone

eve

r w

ant

to u

se a

cond

ucto

r S

o w

hy w

oul

d a

nyone

eve

r w

ant

to u

se a

cond

ucto

r S

o w

hy w

oul

d a

nyone

eve

r w

ant

to u

se a

cond

ucto

r w

ith

a 9

0w

ith

a 9

0w

ith

a 9

0w

ith

a 9

0° °°°C

or a 10

5C o

r a 10

5C o

r a 10

5C o

r a 10

5° °°°C

rating

if

they

can’

t be

applie

d

C rating

if

they

can’

t be

applie

d

C rating

if

they

can’

t be

applie

d

C rating

if

they

can’

t be

applie

d

at th

eir am

paci

ty rating

s fo

r th

ose

tem

per

atu

res?

at th

eir am

paci

ty rating

s fo

r th

ose

tem

per

atu

res?

at th

eir am

paci

ty rating

s fo

r th

ose

tem

per

atu

res?

at th

eir am

paci

ty rating

s fo

r th

ose

tem

per

atu

res?

The

ans

wer

lie

s in

the

fact

tha

t The

ans

wer

lie

s in

the

fact

tha

t The

ans

wer

lie

s in

the

fact

tha

t The

ans

wer

lie

s in

the

fact

tha

t th

ose

hig

her am

paci

ty rating

s th

ose

hig

her am

paci

ty rating

s th

ose

hig

her am

paci

ty rating

s th

ose

hig

her am

paci

ty rating

s

8080

gp

yg

gp

yg

gp

yg

gp

yg

can

be

utilized

whe

n der

ating

due

ca

n be

utilized

whe

n der

ating

due

ca

n be

utilized

whe

n der

ating

due

ca

n be

utilized

whe

n der

ating

due

to

am

bient

cond

itio

ns o

r due

to

to a

mbient

cond

itio

ns o

r due

to

to a

mbient

cond

itio

ns o

r due

to

to a

mbient

cond

itio

ns o

r due

to

exce

edin

g m

ore

tha

n 3 c

urre

nt

exce

edin

g m

ore

tha

n 3 c

urre

nt

exce

edin

g m

ore

tha

n 3 c

urre

nt

exce

edin

g m

ore

tha

n 3 c

urre

nt

carryin

g c

ond

ucto

rs in

a

carryin

g c

ond

ucto

rs in

a

carryin

g c

ond

ucto

rs in

a

carryin

g c

ond

ucto

rs in

a

race

way

race

way

race

way

race

way. ...

Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5° °°°C CCC

8181

Ass

ume

that an

am

paci

ty o

f 60

A is

need

ed in

a c

ircu

it w

ith a

Ass

ume

that an

am

paci

ty o

f 60

A is

need

ed in

a c

ircu

it w

ith a

Ass

ume

that an

am

paci

ty o

f 60

A is

need

ed in

a c

ircu

it w

ith a

Ass

ume

that an

am

paci

ty o

f 60

A is

need

ed in

a c

ircu

it w

ith a

75

75

75

75° °°°C

ter

min

ation

at one

end

and a

60

C ter

min

ation

at one

end

and

a 6

0C ter

min

ation

at one

end

and

a 6

0C ter

min

ation

at one

end

and

a 6

0° °°°C

ter

min

ation

at th

e oth

er

C ter

min

ation

at th

e oth

er

C ter

min

ation

at th

e oth

er

C ter

min

ation

at th

e oth

er

end, w

her

e th

e am

bie

nt is

45

end, w

her

e th

e am

bie

nt is

45

end, w

her

e th

e am

bie

nt is

45

end, w

her

e th

e am

bie

nt is

45° °°°C

. C.

C.

C.

First

, si

nce

one

ter

min

ation

tem

per

atu

re rating

is

hig

her

than

the

First

, si

nce

one

ter

min

ation

tem

per

atu

re rating

is

hig

her

than

the

First

, si

nce

one

ter

min

ation

tem

per

atu

re rating

is

hig

her

than

the

First

, si

nce

one

ter

min

ation

tem

per

atu

re rating

is

hig

her

than

the

oth

er, th

e lo

wes

t one

mus

t be

used

, w

hic

h is

60

oth

er, th

e lo

wes

t one

mus

t be

used

, w

hic

h is

60

oth

er, th

e lo

wes

t one

mus

t be

used

, w

hic

h is

60

oth

er, th

e lo

wes

t one

mus

t be

used

, w

hic

h is

60

° °°°C. The

firs

t C. The

firs

t C. The

firs

t C. The

firs

t ch

oice

mig

ht be

a

choice

mig

ht be

a

choice

mig

ht be

a

choice

mig

ht be

a 4

AW

G T

W4

AW

G T

W4

AW

G T

W4

AW

G T

Wco

nduc

tor w

ith

an

am

paci

ty o

f co

nduc

tor w

ith

an

am

paci

ty o

f co

nduc

tor w

ith

an

am

paci

ty o

f co

nduc

tor w

ith

an

am

paci

ty o

f 70

A a

t 60

70

A a

t 60

70

A a

t 60

70

A a

t 60

° °°°C.

C.

C.

C.

Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5° °°°C CCC

How

ever

, in

the

NEC® the

Correc

tion

Fact

ors

rev

eals

that th

e 70

A

How

ever

, in

the

NEC® the

Correc

tion

Fact

ors

rev

eals

that th

e 70

A

How

ever

, in

the

NEC® the

Correc

tion

Fact

ors

rev

eals

that th

e 70

A

How

ever

, in

the

NEC® the

Correc

tion

Fact

ors

rev

eals

that th

e 70

A

8282

am

paci

ty m

ust be

der

ate

d d

ue to the

45

am

paci

ty m

ust be

der

ate

d d

ue to the

45

am

paci

ty m

ust be

der

ate

d d

ue to the

45

am

paci

ty m

ust be

der

ate

d d

ue to the

45° °°°C

am

bie

nt, by a

fact

or of

C a

mbie

nt, by a

fact

or of

C a

mbie

nt, by a

fact

or of

C a

mbie

nt, by a

fact

or of

0.7

1. Thi

s yie

lds

a n

ew a

mpaci

ty o

f 4

9.7

A, w

hic

h is

les

s th

an

the

0.7

1. Thi

s yie

lds

a n

ew a

mpaci

ty o

f 4

9.7

A, w

hic

h is

les

s th

an

the

0.7

1. Thi

s yie

lds

a n

ew a

mpaci

ty o

f 4

9.7

A, w

hic

h is

les

s th

an

the

0.7

1. Thi

s yie

lds

a n

ew a

mpaci

ty o

f 4

9.7

A, w

hic

h is

les

s th

an

the

requi

red 6

0. This

is

wher

e a c

ond

ucto

r w

ith a

hig

her

tem

per

atu

re

requi

red 6

0. This

is

wher

e a c

ond

ucto

r w

ith a

hig

her

tem

per

atu

re

requi

red 6

0. This

is

wher

e a c

ond

ucto

r w

ith a

hig

her

tem

per

atu

re

requi

red 6

0. This

is

wher

e a c

ond

ucto

r w

ith a

hig

her

tem

per

atu

re

rating

bec

om

es u

sefu

l. A 4

AW

G T

HHN

cond

ucto

r has

a 9

0ra

ting

bec

om

es u

sefu

l. A 4

AW

G T

HHN

cond

ucto

r has

a 9

0ra

ting

bec

om

es u

sefu

l. A 4

AW

G T

HHN

cond

ucto

r has

a 9

0ra

ting

bec

om

es u

sefu

l. A 4

AW

G T

HHN

cond

ucto

r has

a 9

0° °°°C

C

C

C

am

paci

ty o

f 9

5A.

am

paci

ty o

f 9

5A.

am

paci

ty o

f 9

5A.

am

paci

ty o

f 9

5A.

Again

, lo

okin

g a

t th

e ta

ble

at th

e bottom

of

Table

310

.16, a f

act

or

Again

, lo

okin

g a

t th

e ta

ble

at th

e bottom

of

Table

310

.16, a f

act

or

Again

, lo

okin

g a

t th

e ta

ble

at th

e bottom

of

Table

310

.16, a f

act

or

Again

, lo

okin

g a

t th

e ta

ble

at th

e bottom

of

Table

310

.16, a f

act

or

of

.87 m

ust be

used

, due

to the

45

of

.87 m

ust be

used

, due

to the

45

of

.87 m

ust be

used

, due

to the

45

of

.87 m

ust be

used

, due

to the

45° °°°C

am

bie

nt. This

yie

lds

a n

ew

C a

mbie

nt. This

yie

lds

a n

ew

C a

mbie

nt. This

yie

lds

a n

ew

C a

mbie

nt. This

yie

lds

a n

ew

am

paci

ty o

f 82

.65, w

hic

h is

adeq

uate

for th

e re

qui

red 6

0A

am

paci

ty o

f 82

.65, w

hic

h is

adeq

uate

for th

e re

qui

red 6

0A

am

paci

ty o

f 82

.65, w

hic

h is

adeq

uate

for th

e re

qui

red 6

0A

am

paci

ty o

f 82

.65, w

hic

h is

adeq

uate

for th

e re

qui

red 6

0A

am

paci

ty.

am

paci

ty.

am

paci

ty.

am

paci

ty.

Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5Exa

mple

: Circu

it a

mpaci

ty req

uire

d: 60

am

ps,

Am

bie

nt: 4

5° °°°C CCC

Coul

d a

6 A

WG

THHN

cond

ucto

r be

used

in

this

applic

ation?

Coul

d a

6 A

WG

THHN

cond

ucto

r be

used

in

this

applic

ation?

Coul

d a

6 A

WG

THHN

cond

ucto

r be

used

in

this

applic

ation?

Coul

d a

6 A

WG

THHN

cond

ucto

r be

used

in

this

applic

ation?

Its

Its

Its

Its

90

90

90

90

° °°°C a

mpacity

is

75A. U

sing

the

fact

or of

0.8

7 f

or th

e 4

5C a

mpaci

ty is

75A. U

sing the

fact

or of

0.8

7 f

or th

e 4

5C a

mpaci

ty is

75A. U

sing the

fact

or of

0.8

7 f

or th

e 4

5C a

mpaci

ty is

75A. U

sing the

fact

or of

0.8

7 f

or th

e 4

5° °°°C

C

C

C

am

bie

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ives

a n

ew a

mpaci

ty o

f 65.2

5, w

hich

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ms

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am

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a n

ew a

mpaci

ty o

f 65.2

5, w

hich

see

ms

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for

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bie

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ives

a n

ew a

mpaci

ty o

f 65.2

5, w

hich

see

ms

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for

am

bie

nt g

ives

a n

ew a

mpaci

ty o

f 65.2

5, w

hich

see

ms

adeq

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for

a req

uire

d a

mpaci

ty o

f 60

A.

a req

uire

d a

mpaci

ty o

f 60

A.

a req

uire

d a

mpaci

ty o

f 60

A.

a req

uire

d a

mpaci

ty o

f 60

A.

8383

How

ever

, a

How

ever

, a

How

ever

, a

How

ever

, a 6

AW

G c

ond

ucto

r of

any

ins

ulation

rating

coul

d n

ever

6 A

WG

cond

ucto

r of

any

ins

ulation

rating

coul

d n

ever

6 A

WG

cond

ucto

r of

any

ins

ulation

rating

coul

d n

ever

6 A

WG

cond

ucto

r of

any

ins

ulation

rating

coul

d n

ever

be

used

in

this

applic

ation

bec

aus

e th

e 60

be

used

in

this

applic

ation

bec

aus

e th

e 60

be

used

in

this

applic

ation

bec

aus

e th

e 60

be

used

in

this

applic

ation

bec

aus

e th

e 60

° °°°C ter

min

al re

qui

res

that

C ter

min

al re

qui

res

that

C ter

min

al re

qui

res

that

C ter

min

al re

qui

res

that

the

smalle

st a

moun

t of

copper

is

a 4

AW

G f

or a 6

0A a

mpaci

ty.

the

smalle

st a

moun

t of

copper

is

a 4

AW

G f

or a 6

0A a

mpaci

ty.

the

smalle

st a

moun

t of

copper

is

a 4

AW

G f

or a 6

0A a

mpaci

ty.

the

smalle

st a

moun

t of

copper

is

a 4

AW

G f

or a 6

0A a

mpaci

ty.

The

The

The

The

am

oun

t of

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ass

oci

ate

d w

ith

a 4

AW

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t of

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oci

ate

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is

is

is

re

qui

red

requi

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requi

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leed

the

right am

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the

term

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to b

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the

term

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to b

leed

the

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rom

the

term

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to b

leed

the

right am

oun

t of

hea

t aw

ay f

rom

the

term

inal . . . .

The

use

of

less

copper

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t ble

ed e

noug

h hea

t aw

ay, and

ther

efore

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use

of

less

copper

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t ble

ed e

noug

h hea

t aw

ay, and

ther

efore

The

use

of

less

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t ble

ed e

noug

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t aw

ay, and

ther

efore

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use

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less

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ther

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ove

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ble

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20

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8585

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8686

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4)(

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115

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116

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ou

gh

co

nd

uct

ors

do

ha

ve

all

ow

ab

le

am

pa

city

ra

tin

gs,

th

ey

als

o h

av

e m

ax

imu

m

am

pa

city

ra

tin

gs,

th

ey

als

o h

av

e m

ax

imu

m

am

pa

city

ra

tin

gs,

th

ey

als

o h

av

e m

ax

imu

m

am

pa

city

ra

tin

gs,

th

ey

als

o h

av

e m

ax

imu

m

all

ow

ab

le

all

ow

ab

le

all

ow

ab

le

all

ow

ab

le s

ho

rtsh

ort

sho

rtsh

ort

- ---cir

cuit

cu

rre

nt

wit

hst

an

d

circ

uit

cu

rre

nt

wit

hst

an

d

circ

uit

cu

rre

nt

wit

hst

an

d

circ

uit

cu

rre

nt

wit

hst

an

d

rati

ng

sra

tin

gs

rati

ng

sra

tin

gs. ...D

ES

IGN

ING

CIR

CU

ITS

FR

OM

CO

ND

UC

TO

R D

AM

AG

E

119

119

Da

ma

ge

ra

ng

ing

fro

m

Da

ma

ge

ra

ng

ing

fro

m

Da

ma

ge

ra

ng

ing

fro

m

Da

ma

ge

ra

ng

ing

fro

m s

lig

ht

de

gra

da

tio

n o

f sl

igh

t d

eg

rad

ati

on

of

slig

ht

de

gra

da

tio

n o

f sl

igh

t d

eg

rad

ati

on

of

insu

lati

on

to

vio

len

t v

ap

ori

zati

on

of

the

in

sula

tio

n t

o v

iole

nt

va

po

riza

tio

n o

f th

e

insu

lati

on

to

vio

len

t v

ap

ori

zati

on

of

the

in

sula

tio

n t

o v

iole

nt

va

po

riza

tio

n o

f th

e

con

du

cto

rco

nd

uct

or

con

du

cto

rco

nd

uct

or

can

re

sult

if t

he

sh

ort

can

re

sult

if t

he

sh

ort

can

re

sult

if t

he

sh

ort

can

re

sult

if t

he

sh

ort

- ---cir

cuit

ci

rcu

it

circ

uit

ci

rcu

it

wit

hst

an

d is

ex

cee

de

d.

wit

hst

an

d is

ex

cee

de

d.

wit

hst

an

d is

ex

cee

de

d.

wit

hst

an

d is

ex

cee

de

d.

DES

IGN

ING

CIR

CU

ITS

FR

OM

C

ON

DU

CTO

R D

AM

AG

E

120

120

DES

IGN

ING

CIR

CU

ITS

FR

OM

C

ON

DU

CTO

R D

AM

AG

E

121

121

Cu

rren

tC

urre

nt--l

imit

ing

Cir

cuit

lim

itin

g C

ircu

it

Bea

ker

Bea

ker

The

The

II22tt

asso

ciat

edas

soci

ated

wit

hw

ith

the

the

asym

met

rica

las

ymm

etri

cal

curr

ent

curr

ent

isisre

quir

edre

quir

edtoto

bebere

duce

dre

duce

dtoto

the

the

equ

ival

ent

equ

ival

ent

II22tt

ofofaa

sym

met

rica

lsy

mm

etri

cal

curr

ent

curr

ent

ororle

ssle

ss

122

122

Beh

avio

r of

a T

ypic

al C

urre

nt

Lim

itin

g Fu

se

123

123

Ca

seC

ase

Ca

seC

ase

1 111: :::

A AAA# ###

10

10

10

10

AW

GA

WG

AW

GA

WG

con

du

cto

rco

nd

uct

or

con

du

cto

rco

nd

uct

or

can

can

can

can

on

lyo

nly

on

lyo

nly

wit

hst

an

dw

ith

sta

nd

wit

hst

an

dw

ith

sta

nd

4 444, ,,,3

00

30

03

00

30

0a

mp

ere

sa

mp

ere

sa

mp

ere

sa

mp

ere

sfo

rfo

rfo

rfo

ro

ne

on

eo

ne

on

ecy

cle

cycl

ecy

cle

cycl

ea

nd

an

da

nd

an

d6 666

, ,,,02

00

20

02

00

20

am

pe

res

am

pe

res

am

pe

res

am

pe

res

for

for

for

for

on

eo

ne

on

eo

ne

- ---ha

lfh

alf

ha

lfh

alf

cycl

ecy

cle

cycl

ecy

cle

. ...In InInIn

the

the

the

the

circ

uit

circ

uit

circ

uit

circ

uit

be

low

,b

elo

w,

be

low

,b

elo

w,

is isisisth

eth

eth

eth

ew

ire

wir

ew

ire

wir

ep

rote

cte

dp

rote

cte

dp

rote

cte

dp

rote

cte

dw

he

nw

he

nw

he

nw

he

nth

eth

eth

eth

ea

va

ila

ble

av

ail

ab

lea

va

ila

ble

av

ail

ab

lesh

ort

sho

rtsh

ort

sho

rt- ---c

ircu

itci

rcu

itci

rcu

itci

rcu

itcu

rre

nt

curr

en

tcu

rre

nt

curr

en

to

fo

fo

fo

f4

04

04

04

0, ,,,0

00

00

00

00

00

0e

xce

ed

se

xce

ed

se

xce

ed

se

xce

ed

sth

eth

eth

eth

ew

ire

wir

ew

ire

wir

ew

ith

sta

nd

?w

ith

sta

nd

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ith

sta

nd

?w

ith

sta

nd

?

40 K

A1.

85 K

A

124

124

Un

de

r sh

ort

Un

de

r sh

ort

Un

de

r sh

ort

Un

de

r sh

ort

- ---cir

cuit

s, t

he

LO

Wci

rcu

its,

th

e L

OW

circ

uit

s, t

he

LO

Wci

rcu

its,

th

e L

OW

- ---PE

AK

® Y

EL

LO

W™

Du

al

PE

AK

® Y

EL

LO

W™

Du

al

PE

AK

® Y

EL

LO

W™

Du

al

PE

AK

® Y

EL

LO

W™

Du

al- ---

Ele

me

nt

fuse

(3

0

Ele

me

nt

fuse

(3

0

Ele

me

nt

fuse

(3

0

Ele

me

nt

fuse

(3

0

am

pe

re C

LF

) is

fa

st a

ctin

g. I

t w

ill c

lea

r &

lim

it s

ho

rt c

ircu

it c

urr

en

t b

efo

re

am

pe

re C

LF

) is

fa

st a

ctin

g. I

t w

ill c

lea

r &

lim

it s

ho

rt c

ircu

it c

urr

en

t b

efo

re

am

pe

re C

LF

) is

fa

st a

ctin

g. I

t w

ill c

lea

r &

lim

it s

ho

rt c

ircu

it c

urr

en

t b

efo

re

am

pe

re C

LF

) is

fa

st a

ctin

g. I

t w

ill c

lea

r &

lim

it s

ho

rt c

ircu

it c

urr

en

t b

efo

re

it c

an

bu

ild

up

to

a le

ve

l hig

he

r th

an

th

e w

ire

wit

hst

an

d. T

he

op

en

ing

it

ca

n b

uil

d u

p t

o a

lev

el h

igh

er

tha

n t

he

wir

e w

ith

sta

nd

. Th

e o

pe

nin

g

it c

an

bu

ild

up

to

a le

ve

l hig

he

r th

an

th

e w

ire

wit

hst

an

d. T

he

op

en

ing

it

ca

n b

uil

d u

p t

o a

lev

el h

igh

er

tha

n t

he

wir

e w

ith

sta

nd

. Th

e o

pe

nin

g

tim

e o

f th

e f

use

is le

ss t

ha

n o

ne

tim

e o

f th

e f

use

is le

ss t

ha

n o

ne

tim

e o

f th

e f

use

is le

ss t

ha

n o

ne

tim

e o

f th

e f

use

is le

ss t

ha

n o

ne

- ---ha

lf c

ycl

e (

less

th

an

0.0

08

se

con

ds)

. In

h

alf

cy

cle

(le

ss t

ha

n 0

.00

8 s

eco

nd

s). I

n

ha

lf c

ycl

e (

less

th

an

0.0

08

se

con

ds)

. In

h

alf

cy

cle

(le

ss t

ha

n 0

.00

8 s

eco

nd

s). I

n

this

pa

rtic

ula

r e

xa

mp

le, t

he

pro

spe

ctiv

e c

urr

en

t le

tth

is p

art

icu

lar

ex

am

ple

, th

e p

rosp

ect

ive

cu

rre

nt

let

this

pa

rtic

ula

r e

xa

mp

le, t

he

pro

spe

ctiv

e c

urr

en

t le

tth

is p

art

icu

lar

ex

am

ple

, th

e p

rosp

ect

ive

cu

rre

nt

let- ---

thru

by

th

e f

use

is le

ss

thru

by

th

e f

use

is le

ss

thru

by

th

e f

use

is le

ss

thru

by

th

e f

use

is le

ss

tha

n 1

,85

0 a

mp

ere

s.

tha

n 1

,85

0 a

mp

ere

s.

tha

n 1

,85

0 a

mp

ere

s.

tha

n 1

,85

0 a

mp

ere

s.

Th

us

the

ab

ov

e e

xa

mp

le is

sa

fe. O

pe

nin

g t

ime

& c

urr

en

t le

tT

hu

s th

e a

bo

ve

ex

am

ple

is s

afe

. Op

en

ing

tim

e &

cu

rre

nt

let

Th

us

the

ab

ov

e e

xa

mp

le is

sa

fe. O

pe

nin

g t

ime

& c

urr

en

t le

tT

hu

s th

e a

bo

ve

ex

am

ple

is s

afe

. Op

en

ing

tim

e &

cu

rre

nt

let- ---

thro

ug

h o

f th

rou

gh

of

thro

ug

h o

f th

rou

gh

of

the

fu

se is

fa

r lo

we

r th

an

th

e w

ire

wit

hst

an

d r

ati

ng

. Co

nd

uct

or

the

fu

se is

fa

r lo

we

r th

an

th

e w

ire

wit

hst

an

d r

ati

ng

. Co

nd

uct

or

the

fu

se is

fa

r lo

we

r th

an

th

e w

ire

wit

hst

an

d r

ati

ng

. Co

nd

uct

or

the

fu

se is

fa

r lo

we

r th

an

th

e w

ire

wit

hst

an

d r

ati

ng

. Co

nd

uct

or

pro

tect

ion

is n

ot

a p

rob

lem

wh

en

th

e c

on

du

cto

r is

pro

tect

ed

by

cu

rre

nt

pro

tect

ion

is n

ot

a p

rob

lem

wh

en

th

e c

on

du

cto

r is

pro

tect

ed

by

cu

rre

nt

pro

tect

ion

is n

ot

a p

rob

lem

wh

en

th

e c

on

du

cto

r is

pro

tect

ed

by

cu

rre

nt

pro

tect

ion

is n

ot

a p

rob

lem

wh

en

th

e c

on

du

cto

r is

pro

tect

ed

by

cu

rre

nt- ---

lim

itin

g f

use

s w

hic

h h

av

e a

n a

mp

ere

ra

tin

g t

ha

t is

th

e s

am

e a

s th

e

lim

itin

g f

use

s w

hic

h h

av

e a

n a

mp

ere

ra

tin

g t

ha

t is

th

e s

am

e a

s th

e

lim

itin

g f

use

s w

hic

h h

av

e a

n a

mp

ere

ra

tin

g t

ha

t is

th

e s

am

e a

s th

e

lim

itin

g f

use

s w

hic

h h

av

e a

n a

mp

ere

ra

tin

g t

ha

t is

th

e s

am

e a

s th

e

con

du

cto

r co

nd

uct

or

con

du

cto

r co

nd

uct

or

am

pa

city

am

pa

city

am

pa

city

am

pa

city

rati

ng

.ra

tin

g.

rati

ng

.ra

tin

g.

Ca

seC

ase

Ca

seC

ase

2 222: :::

Do

es

Do

es

Do

es

Do

es

the

the

the

the

circ

uit

circ

uit

circ

uit

circ

uit

be

low

be

low

be

low

be

low

rep

rese

nt

rep

rese

nt

rep

rese

nt

rep

rese

nt

a aaam

isa

pp

lica

tio

n?

mis

ap

pli

cati

on

?m

isa

pp

lica

tio

n?

mis

ap

pli

cati

on

?( (((1

01

01

01

0A

WG

AW

GA

WG

AW

GT

HW

TH

WT

HW

TH

Win

sula

ted

insu

late

din

sula

ted

insu

late

dco

pp

er

cop

pe

rco

pp

er

cop

pe

rw

ire

wir

ew

ire

wir

eca

nca

nca

nca

nw

ith

sta

nd

wit

hst

an

dw

ith

sta

nd

wit

hst

an

d4 444

, ,,,30

03

00

30

03

00

am

pe

res

am

pe

res

am

pe

res

am

pe

res

for

for

for

for

on

eo

ne

on

eo

ne

cycl

ecy

cle

cycl

ecy

cle

an

da

nd

an

da

nd

6 666, ,,,0

20

02

00

20

02

0a

mp

ere

sa

mp

ere

sa

mp

ere

sa

mp

ere

sfo

rfo

rfo

rfo

ro

ne

on

eo

ne

on

e- ---h

alf

ha

lfh

alf

ha

lfcy

cle

)cy

cle

)cy

cle

)cy

cle

). ...

Yes

.The

40

KA

sho

rt-c

ircu

it c

urre

nt f

ar e

xcee

ds t

he w

iths

tand

of

the

# 1

0

40 K

A

125

125

THW

wir

e. T

he s

low

act

ing

ordi

nary

cir

cuit

bre

aker

(cl

eari

ng t

ime

of 1

cy

cle)

mak

es t

he c

ircu

it m

isap

plie

d.

Wh

at

can

be

do

ne

to

co

rre

ct t

he

ab

ov

e m

isa

pp

lica

tio

n?

Wh

at

can

be

do

ne

to

co

rre

ct t

he

ab

ov

e m

isa

pp

lica

tio

n?

Wh

at

can

be

do

ne

to

co

rre

ct t

he

ab

ov

e m

isa

pp

lica

tio

n?

Wh

at

can

be

do

ne

to

co

rre

ct t

he

ab

ov

e m

isa

pp

lica

tio

n?

1) U

se a

larg

er s

ize

cond

ucto

r (i

.e.,

from

# 1

0 to

# 1

/0 A

WG

),on

e w

ith

a w

iths

tand

rat

ing

grea

ter

than

the

sho

rt-c

ircu

it fo

r 1

cycl

e (S

ee C

hart

).

2) U

se a

n O

CP

D w

hich

is a

cur

rent

-lim

itin

g t

ype

(CLF

or

CLC

B)s

uch

as t

hat

show

n in

the

pre

viou

s ca

se.

126

126

127

127

RE

ME

MB

ER

GE

NT

LEM

EN

, A F

ULL

-BLO

WN

FIR

E

ON

LY N

EE

DS

AN

IG

NIT

ION

. AN

D I

GN

ITIO

N I

S,

YE

S –

IT’S

TH

E R

ES

PO

NS

IBIL

ITY

OF

TH

E

ELE

CT

RIC

AL

EN

GIN

EE

R.

SO

TH

EN

,

IN S

IZIN

G C

IRC

UIT

S &

FE

ED

ER

S, W

E

ALS

O N

EE

D T

O C

ON

SID

ER

TH

E S

IZE

O

F T

HE

SO

UR

CE

TR

AN

SFO

RM

ER

;

128

128

OT

HE

RW

ISE

, WH

AT

SH

OU

LD H

AV

E

BE

EN

A N

ICE

LY-D

ES

IGN

ED

CIR

CU

IT

AC

TU

ALL

Y T

UR

NS

OU

T T

O B

E

GR

OS

SLY

WR

ON

G &

FA

ULT

Y!

The

refo

re, c

ircu

it d

esig

ning

is

not

com

plet

e w

itho

ut f

ault

ca

lcul

atio

ns…

129

129

The

que

stio

n is

…:

‘AR

E W

E D

OIN

G I

T…

?’

END

…EN

D…

END

…EN

D…

130

THAN

K Y

OU

THAN

K Y

OU

THAN

K Y

OU

THAN

K Y

OU

THA

NK

YO

UT

HA

NK

YO

U