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case, no c i rcu i t wi l l be over loaded as the

erence is only 0.4A.

But i f the load is com put ed using the lowt Normal Power Factor (NPF)ballasts l i ke theast "D" shown on Table 4.2, t he resu l t

uld have been en t i re l y d i f f e ren t as fo l l ows:

al Current is: 0.85 A x 1 2 x 2 = 20.4 A

al Power in Volt-Amperes = 20.4 x 120

or 2,448 Volt-Amperes

As prev ious ly shown, if the total load ofse luminaires Is computed based on theminal lamp wattage, the total lamp wattage is0 watts with load current of only 8.0 A. I fmpared w i th 2 ,448 vo l t -amperes a t a cur ren t

w of 2 0 .4 A, that's a lot of difference of 5%! That ' s more than doub le !

Now, i f t he cur ren t d rawn i s 20 .4 A, it wil l

e ly over load a 15A branch c i rcu i t . In fact

20.4 A is too much for a 20A branch c i rcu i t

ecia l ly i f the load is cont inuou s. Ther ef ore ,

t e r m s o f i n pu t d em a n d d r a w n ; ballastsses) consumption, harmonics & displacementwer factors must be taken in to cons idera t ion .

manufac tu rers package these fac to rs "allin the " line current" ra t ings o f t he bal las ts .

t e rms o f power demand , t he vo l t - ampe resencompass a l l when the vo l tage and the

cur ren t a re mu l t ip l i ed . I t means then tha t

e com mon ly ava i lab le low cost , normal

power f ac t o r 40w , 220v ba l l as t ed f l uo rescen t

l amp d i sp l ay i ng a namep l a t e cu r ren t o f abou t

0 .43A i s ac tua l l y d rawing 95 volt-amperes, evenmore than tw ice as compared to the nomina l

40w! Th is now br ings to h igh l igh t the common

error of "watts divided by voltage" to obtain the

current in amperes.

4.4.1: SIDEBAR: LAMP TUBE DIAM ETERS

The l i gh t ing indust ry uses the "8's of an inch principle" as a s imp le ru le of thu mb toi den t i f y t he d i ame t e r o f a l amp ( l ight bulb or

tube). For examp l e : a T5 f l uo rescen t t ube i s

5/ 8 inch in diameter. A T8 f l uo rescen t t ube i s

8 / 8 " or 1 inch i n d iameter . A T 12 t ube i s

12/8" or Vh inch i n d iameter . I ncandescent

lamps fo l low the same pr inc ip le . A FAR38 l a m pis 38/ 8" or 4% inches i n d iameter . An R30

l amp i s 30/ 8" or 3 3/4A inches i n d iameter .

ble 4.1 : LINE CURRENTS OF 220V, 60 Hz FLUORESCENT LIGHTING INDUCTIVE

TYPE NUMBER OF LAMPS MAINS POWER

PER BALL AST CURRENT FACTOR

BTA 15W 1 x 'TL'D 15W 0.34 0.30

BTA 18W 1 x 'TL'D(U) 18W 0.37 0.41

1 x 'TL' 20W 0.37 0.41BTA 30W 2 x 'TL' D15W 0.34 0.471 x 'TL 'D30W 0.36 0.451 X 'TL'30W 0.41 0.40

BTA 36W 2 x 'TL'D18W/ TL 20W 0.37 0.501 x 'TL' D36W/ TL 40W 0.43 0.48

1 x 'TL' D38W 0.43 0.47BTA 58W 1 x 'TL'D(U) 58W 0.67 0.50

1 x 'TL ' 65W 0.67 0.50

Note that ot her manufacturers could have diff erent ballast line currents because power factor correcti on may have been buil t-

in as In high power factor (HPF) ballasts. It 's wort hwhil e to mention t hat normal po wer fact or (NPF) ballasts common inPhilippine market wi th reputable European makes display in thei r nameplates t he fol lowing:

a) 20W: 0.37 A at 220 V, 60 Hz, 3 5 % pf; b ) 40W: 0.43 A at 220 V, 60 HZ, 5 3 % pf

4- 5

ceseeps international design practices: commercial & industrial complexes

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le 4.2: VARIOUS LINE CURRENTS, VOLT-AM PERES, NOM IN AL WATTAGES &

POWER FACTORS FOR VARIOUS SINGLE LAM P FLUORESCENT BALLASTS

Ba l l a s t L i n e

Cu r r en t

Li n e

V o l t a g e

L i n e V o l t -

AM PERES

La m p N o m in a l

W a t t a g e

Ba l l a s t Po w er

Fa c t o r

A 0.350.45

120V120 V

4254

4040

0.950.74

C 0.55 120V 66 40 0.61

D 0.85 120 V 102 40 0.39OTES: * These valu es are taken f rom actual b al lasts man uf actu rers ' d ata.

* For two- lamp b al lasts doubl e the va lues In th is tab le.

Table 4 .4: POWER & CURRENT DEMANDS OF EUROPEAN -M ADE

COM PACT FLUORESENT LAMPS (CFL)

ceseeps Internat ional design pract ices: commercial St industr ial complexes

a r r a n g e m e n t o f l a m p s , s t a r t e r sa n d b a l l a s t s

i t u b epower(W)(1)

p o w e r c o n s u m e d

(W)

cur re n t (A) a t 220V/ 240 V

PF no t e l ec t r on i cco r r ec t e d co r r ec t ed ba l l as t

t u b e

l e n g t h ( cm)

s i n g l e t u b e w i t h st a r t e r 18 2 7 0.37 0.19 6 0

36 4 5 0 .4 3 0.24120

58 69 0.67 0 . 37 i 150si n g l e t u b e w i t h o u t 20 33 0.41 0 . 2 1 60

v

sta r t e r ( 2 ) w i t h 40 5 4 0 .4 5 0 . 26 1 2 0e x te r n a l s t a r t i n g st r i p 65 8 1 0 . 8 0

1

1 5 0t w i n t u b e s w it h s t a r t e r 2 X 18 5 5 0 . 2 7 6 0

2 x 36 9 0 0 . 4 6 1 2 02 x 5 8 1 3 8 0 . 7 2 1 5 0

tw in tub es w i thou t s ta r te r 2 x 40 1 0 8 0 . 4 9 1 2 0si n g l e t u b e w i t h

5 03 6 0 . 1 6 1 2 0

h i g h f r e q u e n c y b a l l a st

co s 0 = 0 .965 6 1 5 0

i

t w i n t u b e s w i t h h i g h 2 x 32 7 2 0 . 3 3 1 2 0f r e q u e n c y b a l l astc o s o = 0 . 96

2 x 50 1 1 2 0 .5 0 15 0

t ype o f lamp lam p p o w e r cu r re n t atp o w e r c o n s u m e d

(W)220/ 240 V(A)

globe lamps with 9 9 0.090ntegral ballast

co s o =0.5 (1)13 13 0 . 11518 18 0.16025 25 0.205

electronic lamp s 9 0.070co s 0 = 0.95 (1)

1 1 0.0901 5 1 5 0 . 13520 20 0 . 1 5 5

amp s with typ e 5 1 0 0.185starter singleonly "U " formncorporated cos 0 =0.35

7 1 1 0.175

9 1 3 0 . 1701 1 15 0.155

(no ballast)10 15 0.190

double 13 18 0.165"U" formco s 0 = 0.45

18 23 0.22026 31 0.315

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4.4 .2: HID BALLASTS LINE CURRENTS

Lif ted f rom a l ight ing (B/A/G Electronics)ta log, (see Tables 4.5 & 4 .6 ); the l i s t ing thee cur rents o f induc t ive (magnet ic) bal lasts

HID luminaires may help in s iz ing loads for

c i rc ui t . No te t ha t o the r m anu fac tu r e r s '

ta logs may have featured lower bal las t l ine

r rents because po wer fac tor cor rec t ion may

have been bu i l t -in fo r wh ich they no rmal ly

car ry e levated pr ices . To a ugm ent th is

discuss ion, Tables 4 ,1 61 4 .4are l i f ted f rom IECINSTALLATION GUIDE handbook , s how ing l i ne

cur rents fo r both nor mal and h igh pow er fac tor

European-made ba l las ts .

Table4.5: LINECURRENTS OF NPF& HPF INDUCTIVE BALLASTS; 220V, 60 HZ,FOR HIGH PRESSURE SODIUM VA POR (H S) fit M ETAL HALIDE LAM PS (H I)

Make: B/ A/ G ELECTRON ICS, Model: HI/ HS _____ _________

La mp N o m i n a l

Po w er

S o c k e t N o r m a l Po w er

Fa c t o r

L i n e Cu r r e n t

(A m p s ) @

N o r m a l PF

Ca p a c i t o r s i f

S u p p l i ed

( u F)

Co m p e n s a t ed

L i n e Cu r r e n t

(A m p s )

35W E 27 0.41 0.53 5 0.235OW E 27 036 0.76 8 0.31

70W E 27 0.42 1.00 10 0.40100W E 40 0.44 1.20 10 0.57

150W E 40 0.42 1.80 16 0.80

250W E 40 0.42 3.00 25 1.35

400W E 40 0.43 4.45 40 2.00

600W E 40 0.44 6.20 55 3.00

1000W E 40 0.45 10.3 85 5.30

IDEBAR:

* The above table is lift ed from B/ A/ G ELECTRONICS Publicati ons, Note the line current s of ballast s at Nonna! Power Factor(NPF) andat Compensated Power Factor (HPF). Note also the size of capacitors required for such compensation.

- For Compact Fluorescent Lamps (CFL), it is best to refer to technical cat alogs especially the li ne current s.

If Electronics Ballasts are to be used in the installati on, suitable catalog must be referred to,___________________________

Table4.6 : LIN E CURRENTS OF NPF & HPF IN DUCTIVE BALLASTS, 220 V, 60 HZ,

HIGH PRESSURE M ERCURY (HM ) & M ETAL HALIDE (H I) LAMPS

Make: B/ A/ G ELECTRON ICS, Model: HM/ HI

La mp No mi n a l

Po w er

So c k et Po w er

Fa c t o r

Li n e

Cu r r en tCa p a c i t o r s i f

S u p p l i e d (uF)

Co m p e n s a t ed

L i n e A m p s

50W E 27 0.44 0.61 6 0.28

80W E 27 0.51 0.80 7 0.43

125W E 27 0,57 1.15 10 0.65

250W E 40 0.58 2,15 15 1.30

400W E 40 0.56 3.50 30 1.81

1000W E 40 0.63 7.50 50 5.00

The above table is lif ted from B/ A/ G ELECTRONICS Publicat ions.

indus t r ia l and manufac tur ing p lant

, High In tensity Discharge (HID)s are co mmo n l i ght ing instal lat i ons as ide

the Fluorescent Lumina i res . HID lamps

mercury vapor (M V) & metal halide

High - In tens i t y D is c ha r ge Lum ina i r es

require bal las ts . Because they are

ba l las ted, the calculated load must be based on

the ampere rating of the units. This is so

because whi le the tan dem of lamp & bal las t

c ons um es wa t t s , t he i nduc t i v e power f ac to r

and the harmonics d is tor t ion occur r ing in the

ba l las t i t se l f have to be taken in to account .

ceseeps i nternational design practices: commercial 81 industrial complexes