CT measuring circuit with PIC
Some missing specs, will assume PIC DC supply (along with voltage reference for 10-bit ADC) is +5V. Therefore, the maximum peak-to-peak voltage signal at ADC input should be 5V peak-to-peak, with a +2.5V DC offset. ADC reference voltage would be +5V.

If you really must provide a linear current-sense up to 30A from the current transformer, then peak-to-peak current would be 84.8A (the 30A is RMS current). This current is reduced by a factor of 1000 to 84.8 mA peak-to-peak flowing through the current transformer load resistor. A load resistor of 58.92 ohms would produce five volts peak-to-peak for the ADC.







simulate this circuit &ndash; Schematic created using CircuitLab
You might use the next smaller standard value for R1 (like 56 ohms) so that noise and transients won't over-voltage the ADC input. The large value of R2,R3 may help prevent latch-up on really large transients.

As always, when dealing with high-potential AC with that current transformer, be careful!