Demand - ABB A43 User Manual

Technical Description

5.8 Demand

General
The demand functionality is used to measure and store the maximum and mini-
mum demands of different quantities in the meter. Time is divided into
intervals of a certain length in which the mean values of a set of selected
quantities are measured.
Demand can be configured via Modbus and EQ-bus communication or via
the buttons on the meter.
Note –
Changing time/date will store the current period and start a new one.
If a power fail occurs that lasts over the end of an ongoing period, the period will
be stored when the meter powers up again and a new period will start. If date/time
is not set when the meter powers up again, demand will enter a waiting state until
time/date is set.
Interval length
The interval lengths for demand can be one of the following: 1, 2, 5, 10, 15,
20, 30, 60 minutes.
Storing periods
When the last interval of an ongoing period has finished, the maximum
and/or minimum values are stored and a new period starts.
The length of a demand period can be a day, a week or a month.
Demand has 50 channels which can be configured individually. Each channel
can store up to 200 periods. A stored period contains the demand value, the
date/time of the period and the date/time of the interval when the demand value
was mea-sured. All channels use the same interval, subinterval and period
length. Individ-ual channel parameters are type of demand which have the four
choices maxi-mum, minimum, maximum sliding or minimum sliding and the
number of the demand with the three choices first, second or third (max/min).
The period/interval date and time is stored as end of period/interval. For
instance, if a period starts 2010.01.01 00:00.00 and ends 2010.01.02 00:00.00,
then the stored period will be 2010.01.02 00:00.00.
If there is no free memory space available, the oldest period will be erased
to make room for the most recent one.
Stored periods can be read via communication or directly on the display.
An ongoing period can be ended and a new one started by sending a "freeze de-
mand" via communication.
It is also possible to erase all stored periods by sending a "Reset Demand"
com-mand via communication.
If the time is set backward within an interval the calculation of demand for that
interval is restarted if the channel is configured to store a maximum value (as the
2CMC48001M0201
Revision: C
Before any demand values can be stored, time/date must be set.
67 A43/A44
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