EXTECH MG500 [7/15] Operation

MG500-en-GB_v1.3 3/17

Operation

Powering the meter

Press the ON button to turn the unit on. Press the OFF button to turn the unit off. If the meter

does not switch ON please check that fresh ‘C’ 1.5V alkaline batteries are installed in the battery

compartment located at the bottom of the instrument.

Insulation Resistance Testing Procedure

Warning: The circuit under test must be completely de-energized and isolated before making

test connections.

1. After turning the unit on, make sure that the Replace Battery message is not displayed. If

the Replace Battery message is displayed replace the batteries before proceeding.

2. The test voltage defaults to 2500V on power up. Select the desired test voltage using the

Voltage Adjust buttons (±500V) that step through the available test voltages in 500V

increments or by pressing one of the preset test voltage buttons (10kV, 5kV, 2.5kV, 1Kv).

3. The display shows the Connect Leads prompt along with the selected test voltage value.

Connect the Green test lead to the Green test socket on the meter and then to the Ground

side of the insulator under test.

Connect the Red lead to the Red test socket on the meter and the Blue guard cable to the

blue socket on the meter. Connect the service end of the Red cable to other side of the

insulator under test.

If a Leakage Guard lead is required to collect surface leakage, connect the separate Blue test

lead into the Blue guard lead from the Red test lead which is plugged into the Blue test

socket on the meter and then clip the service end of the cable to the surface of the insulator

under test.

4. Momentarily Press the TEST START/STOP button (1.5s

〜3 seconds) to start testing.

For DAR or PI testing – refer to the separate test procedure below.

5. The Insulation resistance test will complete in 5 seconds. The test voltage percentage

steadily counts down to zero during the test as can be seen on the display. The resistance

test result value will appear on the display when the test has completed.

6. The HOLD icon will appear in place of the bargraph when the test is complete and after the

voltage has been discharged.

WARNING: DO NOT REMOVE THE TEST LEADS BEFORE THE HOLD DISPLAY APPEARS.

7. The meter automatically discharges the system at the end of the test.

8. To take another test, press the TEST START/STOP button, the Connect Leads prompt should

appear on the display; the instrument is now ready to run a new test.

9. The instrument automatically powers down after 5 minutes of inactivity.