The high precision Current Comparators (current transformers) are used to convert high currents to a lower, measurable level. The errors of conventional standard current transformers inevitably depend on their burden. A magnetic flux in the core produces the e.m.f. which sustains the secondary current in the burden. This disadvantage has been eliminated by the
development of the new current comparators. An indicator winding measures the magnetic flux in the core, while an amplifier – by regulating the current in a compensating winding – ensures that the amplitude of the residual flux in the core is approximately zero.

Advantages

• Wide current measurement spectrum – Extended current measurement, from mA to kA allowed with one single device. The secondary tapping is provided for maximum versatility.
• Accuracy at best level – The 476x units are prepared for accuracy testing of current instrument transformers with most stringent accuracy requirements – 476x units are qualified for use as standard current transformers in metrology institutes
• Extending other instruments measurement capabilities – 476x units allows a current measurement range extension above 15 A for the 2823 series.
• On-board fault indication and unit self-protection
• Ease of handling and mobility – Standard units customized for temporary and mobile test arrangements.
• Highest versatility in current taps combinations

Applications

• Current instrument transformers (LV/MV/HV)
• Current instrument transformers for switchgears, MV/HV cables, busbars, bushings
• Losses on shunt reactors
• Power capacitors
• Metrology institutes
• Research and development