Megger Three-Phase TTR, Инструкция по эксплуатации

Страница: 36 / 70

M
AVTMTTR330 Rev 3 March 2010
28
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.
PHASE A (or B, or C) TURNS RATIO TOO HIGH
This message shows that a transformer under test turn ratio is higher than 10,000
(if 80 V or 40 V is used) or is higher than 4,000 (if 8 V is used). The message may
be caused by poor connection of one of the test leads, as well.
CHECK PHASE A (or B, or C) CONNECTIONS, REVERSED
This message is caused by incorrect connection of the H and X leads. The H and
X leads have either been reversed or the test transformer connections or
markings do not comply with the requirements of ANSI, IEC, or the Australian
standard. The message may be caused by wrong diagram number specified, as
well.
CHECK PHASE A (or B, or C) POLARITY
This message shows that the H or X test leads are incorrectly connected or the
test transformer connections or markings do not comply with the requirements
of ANSI, IEC, or the Australian standard.
Upon completion of TEST – Powering down
1. Upon completion of testing, press the (Power Suspend) button on the
TTR330 to prepare the unit for shutdown. Then, once directed by the on-
screen instruction, Switch the ON/OFF Switch to OFF.
2. Using an adequately grounded Safety Ground Stick, ground all exposed high
voltage connections. Then, while wearing the appropriately rated rubber
gloves, connect Safety Ground Jumpers from all exposed high voltage cable
terminals to Local Station Earth Ground. It is a good idea to leave the
jumpers in place for at least as long as the specimen was at test voltage.