Electricals - Current Transformer

Central to all of the AC power transducers is the measurement of current. This is accomplished using a current transformer (CT), a "donut" shaped device through which is threaded the wire whose current is to be measured.

A current transformer is designed to produce either an alternating current or alternating voltage proportional to the current being measured. The CTs used with the Wattnode transducers produce a 333 mV alternating voltage when the rated current is measured (either 30A, or 50A). The OSI power transducers employ CT's that produce 5V output at rated value.

All of the 15 CT's employed in the energy monitoring system are "split core." This allows the CT to be opened, installed, and closed, without disconnecting the circuit to which they are attached.