Current Transformers for Active Harmonic Filters

[Shark96]

Hello. We have Siemens 400 V switchgear installed at our site. One of the load breaker supplies power to Active Harmonic filters. The CT on the breaker become heated up and faulty after some time. This has happened twice now. Please suggest what could be the reason for this?

 

[cranky108]

CT's I believe are designed for a specific frequency, where harmonic filters operate with harmonics. That said, are you operating out side the design the CT was intended for?
CTs can fail from heat, too much current on the secondary. Or they can fail from heating of the iron, out side the design limits.