Campbell Scientific CS10-L and CS15-L Current Transformers - Manual (Page 21)

Appendix A. Theory of Operation
A.1 Typical Electrical Circuit
An example of a typical electrical circuit is a generator that provides energy in
the form of a 60-Hz sine wave. The energy is carried from the point of
generation to the point of consumption via two wires. The generator creates an
electrical load that lights up the light bulb (see Figure A-1).
FIGURE A-1. Generator schematic
If we want to know the consumption (amps) of the load, we need a way to
measure what is passing through the wires.
We can add a sensor into the circuit to measure the amperage going through
the circuit (see Figures A-2 through Figure A-4). This sensor is called a CT or
Current Transformer. Our CS10 and CS15 are current transformers.
A-1