4.3
VT/PT
4.3.1
VT/PT Example Connections
Here is an example of connections to an ordinary 7200:120/240 distribution
transformer with center-tapped secondary winding.
- Typical Connection
H
RED
H
BLACK
- Alternate Connection
H
RED
X
BLACK
Note: Unlike other instruments, the DTR
impose polarity restrictions or "forced" auto-connections, thus there
are several valid hookups and virtually all transformer configu-
rations can be tested. In all tests, a negative sign preceding the
displayed ratio indicates phase reversal (inverted polarity) of the
sensed X signal relative to the excitation signal at H. In using the
DTR
, always note the color code of test cable boots.
®
10
RATIO 60.00 : 1
X
H
RED
X
BLACK
RATIO 30.00 : 1
H
X
RED
H
H
BLACK
Digital Transformer Ratiometer DTR
PRIMARY
7200 : 240CT
RED
PRIMARY
7200:240CT
RED
BLACK
Model 8500 does not
®
SECONDARY
X
RED
X
BLACK
SECONDARY
X
RED
X
BLACK
Model 8500
®