Megger MTR105, Руководство пользователя

Страница: 19 / 100

4. Insulation Resistance Tests
Warning: Hazardous voltages are emitted throughout the insulation resistance tests. Do not touch the
test leads while testing is in progress (after test button has been pressed). The warning triangle will flash
on the display during these tests.
Insulation resistance tests can be carried out at the following settings 50 V, 250 V, 500 V, 1 kV and variable voltage
(variable symbol). These are all coloured red and are positioned across the top of the rotary switch.
The test method for each voltage setting is identical.
Variable voltage is user selectable, Refer to 14. Settings on page 71 . The variable voltage setting is configurable
between 10 V to 999 V.
4.1 Insulation test options
Icon Description
IR: Insulation resistance.
PI: Polarization Index is the ratio between insulation resistance values recorded at 1 minute
(assigned t1) and 10 minutes (assigned t2).
DAR: Dielectric Absorption Ratio, it is the ratio between the insulation resistance values at 15 or
30 seconds (assigned t1) and at 60 second interval (assigned t2). i.e. after 30 seconds and 60
seconds. DAR = 15 or 30 (default) second value / 60 second value
T(s): Time IR = Selectable from 1 minute to 10 minutes, in 1 minute increments.
3P 3 Phase. To test insulation resistance phase to phase.
F
This warning triangle flashes when any voltage is being output in the insulation resistance test
process.
4.2 Two Terminal and Guard
The MTR105 is fitted with a guard terminal. The guard terminal is used to conduct leakage currents away from the
measured circuit to reduce errors.
The guard terminal is only used for insulation testing and as and additional connection in 3-phase testing. The lead is
coloured blue.
The guard lead (G) is optional. When used, it should be connected to the guard conductor, screen, steel wire
armoured conductor, or “user added” conductive wire or wrapper, such as foil.
For further information refer to Guide to Motor Testing published by Megger.
Insulation Resistance Tests
www.megger.com 13