CALIBRATION OF SINGLE PHASE ENERGY METER BY DIRECT LOADING METHOD AIM:
To calibrate the given energy meter by direct loading method
APPARATUS: S.No
Equipment
Rn!e
T"pe
10 A
AC
1
Variac,single phase
2
Voltmeter
300 V
AC
3
Ammeter
0-10A
AC
4
Rheostat
!attmeter
" #$
AC
%
&ingle phase energy meter
10A
AC
#untit"
AC
THEORY:
The calibration o' energy meter may become inacc(rate d(ring its vigoro(s (se d(e to vario(s reasons) *t is necessary to calibrate the meter to determine the amo(nt o' error i)e) its reading so that same meter can be (sed 'or correct meas(rement o' energy) *n this method precision grade indicating instr(ments are (sed as re'erence standard) These indicating instr(ments are connected in the circ(it o' meter (nder test) The c(rrent and voltages are held constant d(ring the test) The n(mbers o' revol(tions made by the test are recorded) The time ta+en is also meas(red) nergy recorded by meter (nder test test R. / . . +!h)
nergy comp(ted 'rom the readings o' the indicating instr(ment +! t !here R. n(mber o' revol(tions made by disc o' meter (nd er test)
. n(mber o' revol(tions per +!h 'or meter (nder test,
+! poer in +iloatt as comp(ted 'rom readings ' indicating instr(ments t time in ho(rs) #ercentage rror
R. / . - +! t -------------------------
. 100
+! t 5e'ore cond(cting any o' these tests on a att ho(r meter its potential circ(it m(st be connected to the s(pply 'or one ho(r in order to enable the sel' heating o' the potential coil to stabili6e)
CIRCUIT DIAGRAM:
$i!u%e:& PROECEDURE:
1) eep the A(totrans'ormer at 6ero position) 2) 7a+e connections as per the Circ(it diagram shon belo) 3) &itch on the 230 VAC, 0 86) poer s(pply) 4) *ncrease the inp(t voltage grad(ally by rotating the A(to trans'ormer in cloc+ise direction) ) Ad9(st the load rheostat so that s(''icient c(rrent 'los in the circ(it) #lease note that the c(rrent sho(ld be less then 4A) %) :ote don the Voltmeter, Ammeter, !attmeter and poer 'actor meter readings 'or di''erent Voltages as per the tab(lar col(mn) ;) :ote don the time by (sing stop atch 'or rotating the disc o' the nergy 7eter 'or 10 times) $ind o(t the percentage error by (sing above e<(ations)
TABULAR COLUMN S. No.
'o(t!e
Cu%%ent
R + No o$
Time
Ene%!" mete%
)'*
)I*
%e,o(ution-
)t* in
%e/in! in 12+
o$ te /i-0
ou%-
No. %e,o(ution )R*3mete% 0on-tnt )1*
RESULT:
2ttmete% Re/in! in 42 5 t
6 E%%o%
CALIBRATION OF ENERGY METER BY PHANTOM LOADING AIM:
To calibrate a given single phase energy meter by phantom loading)
APPARATUS:
S.NO
Equipment
Rn!e
T"pe
Variac, single
2 A, 0-
1
phase
230V
2
Voltmeter
0-300V
AC
3
Ammeter
0-10A
AC
4
Rheostat
!attmeter
#untit"
&ingle #hase %
nergy 7eter
300V, 10A
THEORY:
The calibration o' energy meter may become inacc(rate d(ring its vigoro(s (se d(e to vario(s reasons) *t is necessary to calibrate the meter to determine the amo(nt o' error i)e) its reading so that same meter can be (sed 'or correct meas(rement o' energy) *n this method precision grade indicating instr(ments are (sed as re'erence standard) These indicating instr(ments are connected in the circ(it o' meter (n der test) The c(rrent and voltages are held constant d(ring the test) The n(mbers o' revol(tions made by the test are recorded) The time ta+en is also meas(red) nergy recorded by meter (nder test R. / . +!h)
nergy comp(ted 'rom the readings o' the indicating instr(ment +! t !here R. n(mber o' revol(tions made by disc o' meter (nd er test) . n(mber o' revol(tions per +!h 'or meter (nder test,
+! poer in +iloatt as comp(ted 'rom readings ' indicating instr(ments t time in ho(rs) #ercentage rror
R. / . - +! t -------------------------
. 100
+! t 5e'ore cond(cting any o' these tests on a att ho(r meter its potential circ(it m(st be connected to the s(pply 'or one ho(r in order to enable the sel' heating o' the potential coil to stabili6e) CIRCUIT DIAGRAM:
PROCEDURE
1) eep the A(totrans'ormer at 6ero position) 2) 7a+e connections as per the Circ(it diagram shon belo) 3) &itch on the 230 VAC, 0 86) poer s(pply) 4) *ncrease the inp(t voltage grad(ally by rotating the A(to trans'ormer
in cloc+ise direction) ) Ad9(st the load rheostat so that s(''icient c(rrent 'los in the circ(it) #lease note that the c(rrent sho(ld be less then 4A) %) :ote don the Voltmeter, Ammeter, !attmeter and poer 'actor meter readings 'or di''erent voltages as per the tab(lar col(mn) ;) :ote don the time by (sing stop atch 'or rotating the disc o' the nergy 7eter 'or 10 times) =) $ind o(t the percentage error by (sing above e<(ations)
TABULAR COLUMN: S. No.
Time )t* in ou%-
'o(t!e
Cu%%ent
R + No o$
Ene%!" mete% %e/in!
)'*
)I*
%e,o(ution-
in 12+ No.
o$ te /i-0
%e,o(ution )R*3mete% 0on-tnt )1*
RESULT
E7pt No:
CALIBRATION OF SINGLE PHASE ENERGY METER
Dte:
USING PHASE SHIFTING TRANSFORMER
AIM
To calibrate the given single phase energy meter at (nity and other poer 'actors and to dra the calibration c(rve))
APPARATUS REQUIRED S.No
App%tu- Nme
T"pe
1
&ingle phase energy meter
*nd(ction type
2
Rn!e
1
300 V> 10A, ?#$
&tandard attmeter
#t"
1
3
Voltmeter
7*
0-300 V
1
4
Ammeter
7*
0-10 A
1
%
"amp "oad #hase &hi'ting trans'ormer
230 V,
1
&ingle phase a(to
;)
230/0-2;0 V
trans'ormer
=
&top atch
@
Connecting ires
FORMULAE
nergy meter speci'ication rev/+h Tr(e energy #t Power × Time ) / 3%00×1000 7eas(red energy n
,n
:(mber o' revol(tions
;0
rror
Measured
−
True
True
1
×100
1
THEORY The energy meter is an integrated type o' instr(ment here the speed o' rotation o' the al(min(m disc is directly proportional to poer cons(med and the n(mber o' revol(tion per min(te is proportional to the energy cons(med by the load) The ratings associated ith the energy meter are 1)
Voltage rating
2)
C(rrent rating
3)
$re<(ency rating
4)
7eter constants The driving system o' the meter provides the rotational tor<(e 'or the moving system,
hich in t(rn activates the energy registration system 'or reading p(rposes) The energy meter is operated on ind(ction principle, in hich the eddy c(rrent ind(ced in the al(min(m disc interacts ith the main 'ield and creates the driving tor<(e) This system employs phantom loading) 8ere, the phase shi'ting trans'ormer to s(pply the voltage o' varying poer 'actor to the potential coil o' energy meter) The system phase s(pply is (sed to s(pply c(rrent o' energy re<(ired val(e to the c(rrent coil o' energy meter) Th(s energy meter is tested (nder vario(s poer 'actor loads itho(t applying any act(al load) This is called phantom loading)
PROCEDURE 1) Bive the connections as per the circ(it diagram) 2) &itch on the three phase s(pply thro(gh phase shi'ting trans'ormer) Also sitch on the single phase s(pply thro(gh a(totrans'ormer) The a(totrans'ormer sho(ld be +ept in minim(m position be'ore sitching on) 3) &et the A c(rrent in ammeter ith the help o' a(to trans'ormer) 4) :o note don the voltage, c(rrent and poer 'rom the respective meters) Also note the time re<(ired 'or the disc to rotate h(ndred times) ) Repeat step 3 'or vario(s poer 'actors The poer 'actor is set ith the help o' phase shi'ting trans'ormer) %) Tab(late the readings and do the necessary calc(lations)
Circuit Diagram
S( No
Mo/ e( C(0 u(ti on
2ttmete% Po8e% O9-e%,e/ A0tu( Re/in! Re/in! )2tt-* )2tt-*
Time $o% n %e, Se0on/-
Po8e% F0to%
Me-u%e/ Ene%!" 18H
T%ue Ene%!" 18H
6 E%%o%
CALIBRATION OF SINGLE PHASE DIGITAL ENERGY METER BY DIRECT LOADING METHOD AIM:
To calibrate the given energy meter by direct loading method
APPARATUS: S.No
Equipment
Rn!e
T"pe
10 A
AC
1
Variac,single phase
2
Voltmeter
300 V
AC
3
Ammeter
0-10A
AC
4
Rheostat
!attmeter
"#$
AC
%
&ingle phase energy meter
10A
AC
#untit"
AC
THEORY: RES ULT:
The calibration o' energy meter may become inacc(rate d(ring its vigoro(s (se d(e to vario(s reasons) *t is necessary to calibrate the meter to determine the amo(nt o' error i)e) its reading so that same meter can be (sed 'or correct meas(rement o' energy) *n this method precision grade indicating instr(ments are (sed as re'erence standard) These indicating instr(ments are connected in the circ(it o' meter (nder test) The c(rrent and voltages are held constant d(ring the test) The n(mbers o' revol(tions made by the test are recorded) The time ta+en is also meas(red) nergy recorded by meter (nder test R. / . +!h)
nergy comp(ted 'rom the readings o' the indicating instr(ment + ! t !here R. n(mber o' imp(lse o' meter (nder test)
. n(mber o' revol(tions per +!h 'or meter (nder test,
#ercentage rror
+!
R. / . - +! t -------------------------
. 100
poer +! t +iloatt as 5e'ore cond(cting any o' these tests on a att ho(r meter its potential circ(it m(st be connected to the s(pply 'or one ho(r in order to enable the sel' heating o' the comp(ted potential coil to stabili6e) 'rom CIRCUIT readings ' DIAGRAM:
indicating instr(ment s t time in
PROECEDURE:
1) eep the A(totrans'ormer at 6ero position) 2) 7a+e connections as per the Circ(it diagram shon belo) 3) &itch on the 230 VAC, 0 86) poer s(pply) 4) *ncrease the inp(t voltage grad(ally by rotating the A(to trans'ormer in cloc+ise direction) ) Ad9(st the load rheostat so that s(''icient c(rrent 'los in the circ(it) #lease note that the c(rrent sho(ld be less then 4A)
%) :
!attmeter and poer 'actor meter readings 'or di''erent Voltages as per
o
the tab(lar col(mn)
t
;) :ote don the time by (sing stop atch 'or rotating the disc o' the nergy 7eter 'or 10 times) $ind o(t the percentage error by (sing above
e
e<(ations) d o TABULAR COLUMN n
S. No.
'o(t!e
Cu%%ent
R + No o$
Time
Ene%!" mete%
)'*
)I*
%e,o(ution-
)t* in
%e/in! in 12+
o$ te /i-0
ou%-
No. %e,o(ution
t h
)R*3mete% 0on-tnt
e
)1*
V o l t m e t e r ,
A m m e t e r ,
RESULT:
2ttmete% Re/in! in 42 5 t
6 E%%o%
MEASUREMENT OF RESISTANCE USING 2HEATSTONE BRIDGE AIM
To meas(re the given medi(m resistance (sing !heatstone bridge)
Apparatus Required S(.No.
App%tu-
Rn!e
#untit"
1
!heatstone bridge +it
--
1
2
?n+non resistance
--
1
3
Balvanometer
--
1
4
#atch card
--
%
Teo%"
*t is (sed 'or the meas(rement o' medi(m resistances) Very high degrees o' acc(racy can be achieved ith the !heatstone bridge) *t has 'o(r resistive arms, consisting o' resistances R 1, R 2, R 3 and R 4 together ith a battery so(rce and a n(ll detector (s(ally a galvanometer or other sensitive c(rrent meter) The c(rrent thro(gh the galvanometer depends on the potential di''erence beteen points C and ) The bridge is said to be balanced hen there is no c(rrent thro(gh the galvanometer or hen the potential di''erence across the galvanometer is 6ero) $or bridge balance e can rite, *1 R 1 *2 R 2 $or galvanometer c(rrent to be 6ero, the 'olloing conditions also eDistE
1
Procedure •
The (n+non resistance is connected to the +it) Ratio arm is set to some val(e)
•
5y ad9(sting the resistance R 1 the galvanometer is made to indicate n(ll position or 6ero, indicating balanced condition)
•
The val(es o' resistance are noted (sing m(ltimeter)
•
The (n+non resistance is calc(lated 'rom these val(es) •
WHEASTONE RID!E "ETHOD
•
T9u(tion
• • •
•
S %.No.
•
'(ue m%4e/ •
R
•
Ω
•
Ω
Un4no8n %e-i-tn0e R 7
R m
•
•
•
Ω
•
Ω
•
1000
•
1000
•
1000
•
•
1000
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
• • • •
MODEL CALCULATION
• • • • • • • • • • • • •
RESULT • • • • • • • • • • • • • •
•
