AC Energy Monitor

MEXICOWANDERER wrote:
No.

One nick-name for these things is "Doughnut". Everything is inductive with the current transformer.

The hardest thing involved is to disconnect a hot wire and slip the doughnut down it to a convenient resting area. Much easier, faster and simpler than connecting a DC shunt.

A "split" current transformer takes care of slipping the wire through WITHOUT the need of disconnecting the wires.

SEE THIS LINK

However, current transformers are good only for AC, the do not work for DC circuits.

Current transformers are in fact a transformer, the AC lead going through the toroid is the primary winding and the secondary is the output leads. Depending on the ratio of the secondary windings you can "measure" a variety of low current to extremely high AC currents without the need to directly insert a meter into the circuit.

Allows for very remote metering of extremely high AC voltage and or AC current.

Additionally one MUST make sure if they are buying a current transformer that they know the difference between one that has a "burden" resistor or not. Current transformers MUST have a burden resistor across the output leads, this prevents lethal voltages from being present without a load attached to the leads.