You may be
familiar with the "tare" weight when using a scale.
For example, if a
100 kg container is placed on a scale and items are inserted
into the container increasing the total weight to 150 kg,, the
tare weight is said to be 100kg. When the tare value is
subtracted from the total weight the item weight of 50 kg is
obtained.
The same
principle is used for identifying the power usage of various
appliances, loads or branch circuits. Before cycling a load to
be analyzed, the software determines the "tare" power of the
service panel being monitored.
Using the
software's "Locate Screen" the Start button is clicked to begin
searching for an increase in power. The load to be identified is
cycled ON by the consumer and detected by the software.
After several
seconds, the consumer turns OFF the load.
The software detects the OFF cycle then graphs the load power
and displays the average load power.
Because the
ECM-1220 monitor reads each half of the panel power separately,
the software identifies which phase (half) the load is connected
to. This is helpful in identifying loads that are cycled when
you are away or sleeping.
For
example:
Using the
technique described above, you have determined that the
dehumidifier is connected to Phase B and consumes
approximately 347 watts.
Reviewing the
daily consumption graph for the entire service panel, you discover occasional
increases/decreases on Phase B of approximately 346 watts.
Based on this finding you can determine how often the
dehumidifier is cycled.
The reason I
use this example is because this is a real life example I
experienced. I noticed that my dehumidifier spent a lot of ON
time. I reduced the dehumidifier setting slightly, and noticed
a substantial reduction in ON time with no noticeable change
in humidity or comfort.