In article .com,
"robgraham" writes:


I've done this using a current transformer and meter (moving iron?) from RS
with a 0-80A scale.

I removed the incoming live meter tail from the CU to feed it through the
current transformer.

Beware of an often unrecognised danger of current transformer's -- never
leave the secondary open circuit (short it out if you aren't using it),
and never fiddle with the connections to it without first switching off
the primary. You can get thousands of volts from the secondary if it is
erronously left open circuit.

Absolutely - what's the point in attempting to measure power when all
you really need is the current - the voltage doesn't not vary more than
a few percent whereas the current goes from effectively zero to well,
60 A and is as good a measure of the consumption as anything.

Depends if you want to measure the current or the power. Many loads
nowadays are far from unity power factor, in which case the current
doesn't give you a good idea of the power.

--
Andrew Gabriel