8/12/2019 EXPERIMENT7open ,Short Ckt

1/3

ASCT/EEE/LAB/BEE-07

(Open & Short Circuit Test)

EXPERIMENT NO. - 07

AIM: - To Perform Open Circuit Test & Sort Circuit Test on ! Sin"#e P!se

Tr!nsformer to $etermine Te P!r!meters Of Te E%ui!#ent Circuit.

INSTR'MENTS RE('IRE$:

S. No. Instruments Range Qty.

1. Single Phase ariac 0-!"0 0#

!$ %atteter 'nao eter Tpe !$*/*A+ #*0/"00 0#

"$ Aeter (,) 0-* A 0#

$ Aeter (,) 0-!0 A 0#

*$ olteter (,) 0-"0 0#

.$ olteter (,) 0-"00 0#

7$ Single Phase Transorer #A 0#

T)EOR*:-

(A) Open Circuit Test

, one o the 1in2ing o a single-phase transorer is3 ept open circuite2 an2 AC suppl

is gi4en to the other 1in2ing3 the transorer taes a sall current calle2 the no load current,

1hich is o the or2er o ! to *5 o the ull loa2 current$ The no loa2 current has t1o

coponents3 the agneti6ing coponentImpro2ucing the lu in the transorer core an2

the 1oring coponentsI+to suppl the iron core losses in the core$ The sall copper lossesin the 1in2ing at this re2uce2 current are negligi8le$ Thus3 the po1er input to the transorer

un2er this con2itions e9ual iron losses taing place in it$

, %03 0an2 ,0are the rea2ings o the 1atteter3 4olteter an2 aeter respecti4el

2uring no loa2 1hen connecte2 as per the 2iagra$ The no loa2 e9ui4alent paraeters are

calculate2 as ollo1s

cos, 0

/0I0I+ I0cos,

R0 /0I0

(B) Short Circuit Test

,n this test lo1 4oltage 1in2ing is short-circuite2 & eperient is perore2 at high

4oltage si2e (usuall *-#05 o noral priar 4oltage) allo1 4oltage at correct re9uenc

applie2 to the priar is continuousl increase2 until ull loa2 current is lo1ing in the

priar se4en secon2ar$

Page # o "

8/12/2019 EXPERIMENT7open ,Short Ckt

2/3

ASCT/EEE/LAB/BEE-07

(Open & Short Circuit Test)

Since in this test applie2 4oltage is sall percentage o actual 4oltage$ The utual lu

pro2uce2 is also a sall percentage o actual 4alue$ :ence3 core losses are 4er sall$ %ith

the results3 thus 1atteter rea2ing represents ull loa2 copper losses$

i$e. sc /scIsc

Rsc

Isc1

%here3 W= rated ohmic losses; Vsc= rated voltage; Isc= rated current

CIRC'IT $IA2RAM:-

PROCE$'RE:-

(A) Open Circuit Test

#$ The suppl is s1itche2 on 1ith 4ariac as its in$ position$

!$ The 4oltage applie2 to the transorer is a2;uste2$

"$ Onl one set o rea2ing correspon2ing to the rate2 4oltage is suicient to calculate

the coplete result$

Page ! o "

8/12/2019 EXPERIMENT7open ,Short Ckt

3/3

ASCT/EEE/LAB/BEE-07

(Open & Short Circuit Test)

(B) Short Circuit Test

#$ Connect the circuit as gi4en in the circuit 2iagra$

!$ appl 4oltage sc 1ith the help o 4ariac 1hich is re9uire2 to rate2 current

"$