Checking The Correct Connection Of The Cts With Two Current Probes; Checking The Correct Connection Of The Cts With A Fluke 41B - ABB PQFA Instruction Manual

Power quality filter

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9.3.4. Checking the correct connection of the CTs with two current probes.

If the main bus bar is available and all security rules are taken, it is possible to

use the two channel scope meter in order to see if the current measured

through the CT is matching the real current in the bus. Connecting the current

probes as shown on Figure 9.7., the two traces must be in phase and of the

same shape (the magnitude could be different as the gain are different) if the

wiring is correct.

Supply side

Figure 9.7. Connection of the scopemeter for checking CT in phase L1

This operation has to be repeated for the remaining two phases for a

complete check. The current probes have to be changed accordingly.

The Fluke 41B is a power analyser that allows measurements of one voltage

and one current wave. Unfortunately, the device does not allow simultaneous

display of both waveforms on the screen. But it is possible to synchronise the

triggering on either the voltage or on the current. All phaseshift measurements

are then referenced to the chosen origin. To read directly the phaseshift

between the fundamental components, just select the spectrum window of the

signal which is not chosen as the origin.

The instrument must be configured in single phase measurements.

The probes must be connected as shown on Figure 9.2, Figure 9.5 and Figure

9.6.

Positive direction

by comparing the currents.

Asea Brown Boveri Jumet S.A.

PQFA Instructions Manual

X5.6

X5.5

X5.4

PQF

X5.3

X5.2

X5.1

Ch1

Ch2

Load side

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