Omicron CP TD1 Reference Manual

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Appendix
frequencies different from the line frequency and their harmonics, together with
measurements using selective filtering techniques, the test equipment can be
operated on-site, even in substations with high electromagnetic disturbances.
12.9.4 Winding Resistance Measurement and On-Load Tap
Changer Test
Winding resistances are tested in the field to check for loose connections,
broken strands and high contact resistance in tap changers. Additionally, the
dynamic resistance measurement enables an analysis of the transient switching
operation of the diverter switch.
For a better understanding of the resistance measurements, it is necessary to
understand the method of operation of the tap changer (Figure 12-9).
Figure 12-9 Equivalent circuit diagram of On-Load Tap Changer (OLTC)
Tap selector
R
Diverter switch
OLTC

Omicron CP TD1 Specifications

General

Brand	Omicron
Model	CP TD1
Category	Measuring Instruments
Language	English