METREL MI 3298, Instruction Manual With Exercises

Page: 173 / 232

Power Network Application Trainer
– Power generator, transformer, coils
173
E
xe
rci
se
s
E
xe
rci
se
s
n
u
mb
er
S
w
it
ch
Method used
Condition Simulation /
Measuring instrument
Expected result
V
isua
l test
Item 6.1
Safety precautions before test
Safety precautions must be taken
into account
Safety hazards during test
Safety hazards must be taken into
account
After test reminder Must be taken into account
T
ransf
o
rme
r Tu
rn
Rat
ion
and
W
ind
ing
r
es
istan
ce
measur
ement
Item
6.2
Measurement of turn ratio on the
three-phase transformer, regular
state
/
MI3280
r
A
= 10.107
Ω,
∆ r = 0.32%
r
B
= 10.090
Ω,
∆
r = 0.15%
r
C
= 10.109
Ω,
∆ r = 0.34%
@ Uex =80V, fex= 70 Hz
Measurement of turn ratio on the
three-phase transformer, with
simulated problem on winding A
(partial shortcut) and broken
connection on winding C
/
MI3280
r
A
= 20.217
Ω,
∆
r = >100%
r
B
= 10.089
Ω,
∆ r = 0.14%
r
C
= > 8000
Ω,
∆ r = >100%
@ Uex =80V, fex= 70 Hz
Measurement of turn ratio on the
three-phase transformer, with
simulated problem on winding C
(broken connection)
/
MI3280
r
A
= 10.106
Ω,
∆ r = 0.31%
r
B
= 10.089
Ω,
∆
r = 0.14%
r
C
= > 8000
Ω,
∆ r = >100%
@ Uex =80V, fex= 70 Hz
Item
6.3
Measurement of winding resistance
measurement on the three-phase
transformer, regular state
/
MI3280
RH
A
= 401,0 Ω RX
A
=4.492 Ω
RH
B
= 400.3 Ω RX
B
=4.460 Ω
RH
C
= 405,0 Ω RX
C
=4.508 Ω
Measurement of winding resistance
on the three-phase transformer, with
simulated problem on winding A
(partial shortcut) and broken
connection on winding C
/
MI3280
RH
A
= 401,0 Ω RX
A
=2.376 Ω
RH
B
= 40
0.7 Ω RX
B
=4.462 Ω
RH
C
= 405,1 Ω RX
C
=>999.9 Ω
Measurement of winding resistance
on the three-phase transformer, with
simulated problem on winding C
(broken connection)
/
MI3280
RH
A
= 401,1 Ω RX
A
=4.494 Ω
RH
B
= 400.8 Ω RX
B
=
4.463 Ω
RH
C
= 405,1 Ω RX
C
=>999.9 Ω