Megger MT0300 - Preparing for a Test; Site Preparation; Making Circuit Connections

AVTMMTO3XX Rev 3 Sept 2013
11
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Preparing for a Test
Site Preparation
Choose a location that meets the following conditions:
 The location is as dry as possible.
 There is no flammable material stored in the vicinity.
 The test area is adequately ventilated.
 Be sure all equipment is de-energized and all terminals of the Unit Under
Test (UUT) are accessible.
 Erect suitable safety barriers to protect the operator from traffic hazards and
to prevent intrusion by unauthorized personnel. User provided Warning
lights are recommended.
 Verify that the Local station ground is intact and has impedance continuity to
earth.
Making Circuit Connections
Connections should be made in the order as listed below.
1. Ground. Use the Megger supplied Safety Ground Cable (15 ft (4.6 m)) to
connect the MTO Wing Nut Ground Terminal directly to Local Station
Earth Ground. Ensure that the Transformer chassis also has a low
impedance connection to Local Station Earth ground potential.
2. Input Power Source Ground. Input Power Source Ground Terminal
should be less than 100 milliohms of impedance to Local Station Earth
Ground.
3. Connect the Input Power Cord. Before making this connection, insure
the Input Power Source meets the requirements as listed in Section 2 Safety
and the specifications as listed in the datasheet. Also make sure that the
ON/OFF switch (Figure 1) is in the OFF position. Connect the input
power cable to the MTO first, then to the power source. At this time,
leave the ON/OFF switch in the OFF position.