Explain the difference between power transformer and current transformer
CT and PT are both a variant transformer, CT converts large current into a small current, PT converts the high voltage into low voltage, which becomes a safe and usable signal for measuring, sampling, and identification to our instruments, meters, and smart protector. CT is commonly used for three unbalance protection, called zero sequences current transformer（ZCT）. 1. Single current measurement (This usage is not recommended, because of the low accuracy of this transformer (P level), low load capacity) 2. Three unbalanced protections, A/B/C all go through it. Ia + Ib + Ic = IO =0 when the power system is normal, if the system leakage or single grounding Ia + Ib + Ic = IO ≠0. When the smart protector receives this signal, it will alarm or even cut off the main circuit