18 5 WHAT THE 2SX-SERIES SCANNER RECORDS
periods, each 15 minutes long. During each 15 minute period, the Scanner
computes the average value for that Profile (voltage, current, etc.). This 15
minute average is then averaged with all the previous days’ averages of that
15 minute period. For example, the first Voltage Daily Profile data point is
the average voltage during the 15 minute period from 12:00am to 12:15am,
averaged again over the entire recording time. If a Scanner is recording for a
week, then this 12:00-12:15am period is averaged seven times over the entire
week.
There are no settings for Daily Profiles. All available Daily Profiles in a
Scanner are always enabled, regardless of the settings for any other record
types. Memory does not run out for a Daily Profile; it just keeps averaging as
long as the recording session lasts (there is a practical limit of about a year).
Some Scanners record just a voltage Profile, others voltage and current. The S-
Series Scanner with power and harmonics options records a Profile for voltage,
current, real, reactive and apparent power, power factor, voltage and current
THD, and phase angle.
5.3.2 Suggested Uses
Daily Profiles are typically used to profile or characterize a parameter, such as
average load current or power factor. Since the Profile is supposed to reflect
average line conditions, the more loads included in the recording, the better
the average. Monitoring a single small load such as a small office building
would not create a very good profile of distribution line conditions (such as
distribution line power factor), since the building would be a small part of the
total distribution load. Voltage is somewhat of an exception in that anywhere
can be good place to create a profile: every other load (at least those nearby)
will see the same distribution line voltage. The ideal location for creating
power factor profiles is where a PFC would be placed to correct power factor.
The voltage Daily Profile is normally used to identify voltage regulation
problems, or other steady-state low/high voltage issues. The current Profile
can be used to identify daily trends in load current. This is also possible
with the apparent power Profile. Power factor and reactive power Profiles can
be used to set PFC timers to correct for power factor only when necessary
during the day. The voltage and current THD Profiles show when harmonic
distortion is present during the day.
The more days the Scanner records, the better the average created by the
Profile. A recording session that just lasts a single day doesn’t incorporate
any daily averaging at all. Since a Profile starts with all zeros, a recording
session that doesn’t even last 24 hours will include some 15 minute blocks with
the data still zeroed. A recording session that doesn’t even last 15 minutes
