Connection For Usual Applications; Wiring For A Ct Test - Omicron Lab CT Analyzer User Manual

CT Analyzer User Manual
2.4

Connection for Usual Applications

2.4.1

Wiring for a CT Test

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This section shows the basic wiring of the CT Analyzer for a CT test.
Observe the general safety rules in section 2.1 on page 21 and the hints and
instructions for improving the quality of the measurement results given in section
2.7 on page 42.
Warning: Feeding test voltage to a tap of a multi-ratio CT can cause life-
threatening voltages on other taps with higher ratios. Do not touch these taps!
Caution: The grounded terminal on the secondary side of the CT always has
to be connected to the black sockets of input "Sec" and the "Output" of the
CT Analyzer. Connecting the red sockets of the CT Analyzer to PE can result
in incorrect measurement and/or cause an automatic abortion of the
measurement with an error message.
Caution: If it is necessary to use clamps for the connection of the
measurement leads to the secondary side of the test object, always use the
4-wire connection technique as described in section 2.7.1 on page 42 in order
to avoid measurement errors.
For a CT test, connect the CT Analyzer as shown in Figure 2-2:
1. Make sure that the primary side of the CT is connected to PE on one side and
open on the other side.
Caution: It is absolutely important to avoid coupling of interferences into the
primary circuit during measurement. Therefore, connect the side of the primary
circuit that is able to receive more interferences to PE (e.g. the side with the
longer line length). The ungrounded side should be the side that receives less
interferences (refer to Figure 2-2).
2. Disconnect the hot side of all secondary windings of the CT in order to
remove any load from the CT. Every kind of load remaining on the secondary
side of the CT during measurement leads to incorrect measurement results
or error messages.
3. Connect the black socket of CT Analyzer input "Prim" to the grounded side
of the CT's primary circuit and the red socket of this input to the open
(ungrounded) side.