Upon opening a distribution panel, one can observe multiple current transformers inside. Some panels may contain only one CT, while others might have five or six. In fact, they all induce current signals from the bus, but the measured currents have different effects. So. The best distribution system is one that will, cost-effectively and safely, supply adequate electric service to both present and future probable loads—this section is intended to aid in selecting, designing and installing such a system. Protective devices like circuit breakers and fuses are essential, especially for transformers operating over 1,000V, to.