Megger DET Series, Руководство пользователя

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9. Under certain circumstances, the instrument may display a noise warning as shown:
This means that interference has been detected which may impair the accuracy of the measurement. In particular, the reading
could be lower than the actual resistance. The resistance of the electrode or system must be verified by an alternative method.
Note :
„ „
The instrument will display the warning triangle and an excessive noise voltage indicator if the ground noise voltage
is above 40 V pk-pk (14 Vrms).
„ „
The instrument will display the warning triangle and a voltage over-range condition if the ground noise voltage is
above 100 V – no resistance reading is possible under this condition.
„ „
The instrument will display the warning triangle above 2 A – no ART testing is possible under this condition.
„ „
The instrument will display the warning triangle and an over-range condition above 20 A – no ART testing is
possible under this condition.
„ „
Ensure that the MCC CLAMP jaw mating surfaces are free of dust and contamination and that they contact
completely when the MCC CLAMP is closed.
„ „
Currents carried by conductors in close proximity to the MCC CLAMP may affect calibration and reduce the
accuracy of measurements made.
Two-clamp stakeless measurement (DET4TC2 and DET4TCR2)
Before making a stakeless measurement, please follow the procedures contained in the sections on MCC CLAMP calibration.
1. Ensure the rotary selector switch is in the OFF position.
2. Connect the instrument as shown in Figure 35.
Figure 35: instrument connection for two-clamp stakeless measurement
g
MCC
MVC