Application Note

From the Fluke Digital Library @ www.fluke.com/library
Application Note
Monitoring power usage:
ve reasons to log power
and energy use
1. Safety
Electricians are often required
to conduct a load study before
adding a new electrical load
to an existing panel or service.
Why? The requirements come
from the electrical Inspector, the
electrical engineer who designed
the project, or the customer
adding the new load and the
reason is to determine if there
is sufficient capacity to add new
loads. A load study involves using
a logger to document existing
load levels (three phase current
draw) over time. That’s where
safety comes in. On the positive
side, a load study can be used to
ensure adherence to local safety
regulations. On the negative side,
failure to perform a load study
before adding new loads can
result in overloading an existing
electrical source, creating electri-
cal safety and reliability hazards.
2. Manage energy costs and
realize savings opportunities
While energy expenditures are
a significant portion of overall
operational cost, many companies
don’t really know where their
energy dollars are being spent,
since all they get is one overall
monthly bill, with no indication
of whether that use was standard
or excessive compared to opera-
tions that month. By logging
power use at the main service
entrance and then at large loads
and secondary supplies, facili-
ties can see how much power is