Calculation Of Maximum Demand; Using The Display To Determine Meter Status - Leviton MDNCT-2SC Manual Del Usuario E Instalación

4 GENERAL METERING FEATURES AND FUNCTIONALITY
4.1.1

Calculation of Maximum Demand

Maximum demand (kW) reports maximum consumed power for a 24-hour period
and is calculated using a 15-minute "sliding window" interval divided into three
5-minute sub-intervals, as follows:
• For dual-element meters, power measurements are combined values for Line
1 and Line 2.
• Power measurements are summed over the 5-minute sub-interval and
averaged at the end of the sub-interval.
• At the end of each sub-interval, demand for the three most recent sub-
intervals is averaged to give a new interval demand value.
• Over each 24-hour period the largest interval demand value for the period is
saved.
• During the first 24 hours after the meter is powered up, the maximum
demand display shows the largest interval demand value calculated since
startup.
• After the first 24 hours of operation, reported maximum demand is updated
only once every 24 hours and shows the largest interval demand for the
previous 24-hour period.
Note that 24-hour maximum demand periods are based on the meter's runtime
since power up, not a real time clock.
4.1.2

Using the Display to Determine Meter Status

Table 7 explains how errors are indicated on the LCD. The table lists error
conditions in order of priority (highest priority first). If more than one error
condition exists, the LCD error screen shows only the highest-priority error.
For installation errors, if the same error condition exists on both lines the LCD
error screen reports the error only for line 1, but both L1 and L2 symbols blink.
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