Logging Session Setup - Fluke 1742 User Manual

1742/1746/1748
Users Manual
Inrush Current
Inrush currents are surge currents that occur when a large or low-
impedance load comes on line. Normally the current will stabilize after
some time when the load has reached normal working condition. For
example, the start-up current in induction motors can be 10x the
normal working current. See Figure 14. The inrush current begins
when the 1/2-cycle RMS current rises above the inrush threshold, and
ends when the 1/2-cycle RMS current is equal to or below the inrush
threshold minus the hysteresis value. In the event table, the extreme
value is the highest 1/2-cycle RMS value of the event.
Threshold
}
(=Trigger)
Hysteresis
Duration
Figure 14. Inrush Characteristics
Parameters to configure:
•
Trigger on/off
•
Limit
The current threshold limit is the ½ cycle RMS value in A. A signal
exceeding this limit triggers the event.
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Logging Session Setup

Name. The Logger auto-generates a file name with the format ES.xxx
or LS.xxx. ES ... Energy Study LS ... Load Study xxx ... incremental file
number The counter resets when the Logger is set to factory defaults.
See Reset to Factory Defaults for details. You can also choose a
custom file name with up to 31 characters.
Description. Enter more details about the measurement, such as
customer, location, and load-rating plate data. This description field is
limited to 127 characters. After you download a logging session with
Energy Analyze software, the description can be also entered or
modified.
Trend Interval. Select the time interval when a new average value is
added to the logging session. The available intervals are: 1 s, 5 s,
10 s, 30 s, 1 min, 5 min, 10 min, 15 min, 30 min. A shorter interval
provides more details at the cost of higher memory consumption.
Examples of when a short interval is useful:
•
Identify duty cycle of frequently switching loads
•
Energy cost calculation of production steps
Demand Interval. Electrical suppliers use this interval to measure
the customer demand. Select an interval to get energy costs and the
maximum demand value (average power measured over a demand
interval). A value of 15 minutes is normal. If the average interval is
unknown, select 5 minutes. You can recalculate other interval lengths
offline using the Energy Analyze Plus software.
This value is not available for load studies.
Note