Megger MOM2, Руководство пользователя

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BD0333FE ZP-BD03E MOM2 9
2 INTRODUCTION
2.2 DualGround – Both
sides grounded
With MOM2 it is possible to make measurements
according to the DualGround™ method. The most im-
portant advantage is improved safety but the method
is also easier and saves time. The number of tasks is
reduced when the ground cable does not need to be
disconnected and reconnected. Permission related
work that may include paper work could many times
be avoided. However, the local safety regulations shall
always be followed.
Using the DualGround method might cause a small
measurement error cause by the current running
through the ground loop. The error value depends on
the relation between the two parallel circuits.
Example : If the test object is 50 µΩ and ground loop
is 10 mΩ the error will be 0.5%
Two 10 m, 95 mm
2
grounding cables has a resistance
of around 3.6 mΩ. Transitional resistance in connec-
tions and clamps to be added.
With both sides grounded the induced current will not pass
through the test instrument.