6-energy-meter.doc

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EXPERIMENT NO. 6

AIM: STUDY AND CALIBRATION OF SINGLE PHASE ENERGY METER.

APPRATUS REQUIRED:

Sl.No.

Name Range Quantity

1. Wattmeter 0-750 Watts 12. Voltmeter 0-300 volts 13. Ammeter 0-10 A 14. am! oa" #an$ 1 %& 15. Single '(ase )nergy

*eter

+00 R,%W 50 / 1

THEORY:

(e total !o&er onsume" y a loa" "uring an interval o time is )N)R.

W(ere )6)nergy '6 'o&er 6ime

t(e voltages 8 urrents not onstant 8 (ave n-values over t(e time tt(en

t an also e e9!resse" as ontinuous integral o 'o&er i.e.

(e unit o energy is Watt seon" or :oule. #ut its ommerial unit is

%ilo&att-(ours or %W( &(i( is "eine" as t(e energy onsume" y a loa"

o 1000 &atts over a !erio" o one (our.


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Energy Meter

n"ution ty!e energy meters are most ommonly orm o an A. . %W(

meter use" to measure t(e energy onsume" in any a.. iruit in a

!resrie" !erio" &(en su!!ly voltage an" re;ueny are onstant in

"ay to"ay lie 8 in in"ustrial installation. )nergy meter is an integrating

instrument &(i( measure t(e total ;uantity o eletrial energy su!!lie"

to t(e iruit in a given !erio". (ese meters measure eletrial energy

in %ilo&att (ours.

PRINCIPLE: (e #asi !rini!le o in"ution ty!e energy meter is

eletromagneti in"ution. W(en an alternating urrent lo&s t(roug( t&o

suitaly loate" oils


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R)S)RN SS)* $ee!s t(e reor" o energy onsume" y loa"

t(roug( &orm &(eel or !inion gear mounte" &it( s!in"le o moving "is.

"OR!ING

W(en t(e energy meter is onnete" in t(e iruit t(e urrent oil arriest(e loa" urrent an" t(e !ressure oil arries t(e urrent !ro!ortional to

t(e su!!ly voltage. (e magneti iel" !ro"ue" y t(e S)R)S magnet

is in !(ase &it( t(e line urrent 8 t(e magneti iel"

!ro"ue" y t(e s(unt magnet is in ;ua"rature &it( t(e

a!!lie" voltage


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)nergy onsume" y &attmeter 6

'erentage )rror 6

6

PROCEDURE:

1. *a$e t(e onnetion as !er t(e iruit "iagram.

2. @ei"e t(e numer o revolution to ta$e t(e rea"ings. t s(oul"

neit(er e too small nor e too large. ou may $ee! t(is et&een 4-

+ Revolutions.3. %ee! t(e loa" at minimum an" s&it( on t(e !o&er su!!ly.

4. a$e t(e rea"ing o )t W an" t rom t(e energy meter &attmeter

an" sto! &at( res!etively. =alulate )s 8 'erentage error.

5. nreases t(e loa" in 5-10 ste!s u!to rate" value o t(e energy

meter an" ta$e t(e rea"ings. S&it( o t(e su!!ly.

rom t(e oservation o t(e magnitu"e o error at "ierent loa"s !re"it

t(e nature o t(e error as given elo&?

1. W(en su!!ly is on an" t(ere is no loa" i.e. &(en its !ressure oil

is only energi/e" i meter rea"s energy y rotation o "is it is

ertainly D=R))' )RRERF.

2. at very (ig( loa"s it rea"s less it is alle" as R=ENA

)RRRER.

3. 3. at very (ig( loa" meter rea"ing is less it may e "ue to

D@NA*= #R)A%N ERQG)F an" re;uires over loa"

om!ensation.

CIRCUIT DIAGRAM:

OBSERATION TABLE:


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S#.N$.

P$%er&!"'

T()e&*e+'

N$. $,Re-$#t($n*&R'

&!"/'

PRECAUTIONS:

1. *a$e sure t(e onnetions areully an" get it (e$e" y your

instrutor eore you s&it( EN t(e su!!ly.

2. a$e t(e rea"ings areully es!eially t(e energy meter rea"ing

an" sto! &at( o!eration must e simultaneous.

3. @onCt tou( t(e live &ires.

4. @o not t(e energy meter eyon" its rating.

5. (e in!ut voltage must e $e!t onstant &it( t(e (el! o

autotransormer.

RESULT:

(e given 1-!(ase in"ution ty!e energy meter is alirate" &it( t(e (el!

o a stan"ar" &attmeter an" sto! &at(. t is oun" t(at !erentage error

"oes not remain onstant rat(er it varies in magnitu"e rom no loa" to

ull loa".

6-energy-meter.doc

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