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AVTMTTR320-EN Rev A Oct 2008
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Remote Control Operation for LTC Testing
Use the remote control mode of the TTR for load tap changer (LTC) testing.
The remote control mode provides two-way-communication between the
operator and the TTR, allowing you to stay close to an LTC, change taps, and
initiate the test routine.
Connect the hand-held control unit, Megger p/n 30915-220, to the Remote
Trigger Receptacle port of the TTR. The remote control unit pushbutton lamp
will illuminate.
Now an operator may come to the remote location, and set (for example), the
LTC to the desired position, and would then depress the remote control unit
pushbutton for a short time, then release it. The pushbutton lamp extinguishes
until the TTR is ready for the next test. When the current testing is complete, the
test results are automatically saved, the test ID is advanced to the next number,
the pushbutton lamp lights, and the TTR test set is ready for the next remote test
Error Messages
When an error message appears in the transformer test result screen indicating an
abnormal operating condition, verify the condition by taking a repeat
measurement before attempting to take any corrective action.
Open connections, wrong connections, open windings, shorted windings, high
resistance windings, other abnormal transformer problems, or a combination of
these may cause a large deviation from normal turn ratio or indicate an unusual
message. The unusual operating conditions may be caused by an abnormal
leakage reactance or capacitive coupling within the transformer windings. If
abnormal operating conditions occur during transformer testing, error messages
may appear (such as below) and may be accompanied by three short beeps.
CHECK CONNECTIONS
This message indicates that the transformer is not connected to the test set. The
message may be caused by poor connection of one of the test leads, as well.
PHASE A (or B, or C) EXCITATION CURRENT TOO HIGH
This message indicates that excitation current exceeds 500 mA. Excitation
current can be reduced by using lower test voltages (40 V or 8 V).
TURNS RATIO TOO LOW, <0.8
This message shows that a transformer under test turn ratio is less than 0.8. The
TTR is not designed to test a transformer turn ratio under 0.8.
Summary of Contents for TTR320 Series
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Page 3: ...Three Phase TTR Transformer Turn Ratio Test Set TTR320 series...
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