Megger MTB7671, Руководство пользователя

Страница: 10 / 14

If the tester fails to indicate a tripped RCD then the tester should be
returned for a full calibration.
✍ - Record the reading on the record card.
To reset the test box press the [reset] button in the yellow panel.
7.6
Conducting a 5I @ 180° Test
To do a 180° 5I test set the tester to 180° 5I mode and perform the
test. The unit will trip and disconnect power. The [Tripped] and
[5 I TEST] LEDs will light. The trip time should be a nominal 20 ms.
If the tester fails to indicate a tripped RCD then the tester should be
returned for a full calibration.
✍
- Record the reading on the record card.
To reset the test box press the [reset] button in the yellow panel.
7.7
Conducting 10 mA, 30 mA and 100 mA tests
The test sequence can be repeated for the 10 mA, 30 mA and
100 mA tests by selecting the appropriate current setting on the RCD
and loop test select switch and repeating the tests as described in
sections 7.2 to 7.6.
NOTE : RCD Protection
In order to protect the current sense circuit the RCD simulator is
protected by a 500 mA fuse. If the fuse blows then the earth pin of
the RCD and loop supply socket will float. If an RCD test is attempted
the fuse blown LED will light. Note that this will only illuminate if the
test instrument does not inhibit testing if the correct voltages are not
present, or the test instrument provides sufficient leakage to light the
LED when connected.
8. Fuse replacement
The MTB77671/2 is protected by two x 500 mA (F) fuses and a 7 A
fuse in the RCD plug. Fuse failure is indicated by either the 230 V
AC LED failing to light or the [Fuse Blown] LED lighting. In the event
of a fuse failing, fuses must be replaced with the same fuse type.
Disconnect the test box from the mains supply. Disconnect any test
instruments from the test box. Remove the failed fuse from the fuse
holder and replace with an identical fuse:
Fuse Type:
500 mA (F) 20 mm
7 A BS1362