AEMC 8500 - 4 Operation; Conducting a Test; Mode Selection

Digital Transformer Ratiometer DTR
®
Model 8500 9
CHAPTER 4
OPERATION
WARNING: The Digital Transformer Ratiometer DTR
®
Model 8500
isdesigned foruseon non-energized(“dead”) transformersonly.
Make sure the test sample is completely disconnected from AC
power and is fully discharged.
4.1 Conducting a Test
1. Connect the DTR
®
test cables in the proper manner to a non-energized
transformer. Refer to Connection Examples (§4.3.1 and §4.4.1).
2. Turn the DTR
®
ON and select the proper test mode. Refer to Mode
Selection below.
3. At Ready, press the test button to begin. Following a brief test cycle,
Ratio, Polarity and Excitation Current will be displayed.
Please refer to VT/PT Testing and CT Testing sections of this manual for
complete operating information (§4.3.2 and §4.4.2).
4.2 Mode Selection
The operating mode of the DTR
®
isconguredatpower-upoftheinstru-
ment. The default test mode is VT/PT. To enter the CT Test Mode, depress
the TEST button while turning the instrument on, and hold until CT Test
Mode Selected is displayed.
• UsetheVT/PTTestModefortestingvoltageandpotentialtransformers
(maximum 44V test excitation).
• UsetheCTTestModefortestingcurrenttransformers(maximum5V
test excitation).
• TheDTR
®
automatically reverts to the VT/PT Test Mode when power is
turned off.