What is a current transformer and why is it needed?

Current transformer (CT) reduces high current to measurable range (5A or 1A). Enables safe metering of circuits >30A without high heat, large conductors.

How does a current transformer work?

Electromagnetic induction principle. High current (primary winding) creates magnetic field. Secondary winding intercepts field, induces proportional lower current.

Where should I install current transformers in my circuit?

Install CT in series with main power conductor, immediately upstream of breaker or downstream of utility meter. One CT per phase (3 CTs for three-phase).