Technical data

2CMC480022C0003| Electricity meters 41
DELTAmax
Generic information - Time dependent functions
Internal clock and time dependant
functions
DELTAmax meter has an internal clock that keeps track of the
date and time and is equipped with various time dependant
functions such as load profile, maximum demand, previous
values, event log, outputs controlled by time and in tariffs.
The tariffs are normally controlled via the internal clock (no
external time switch required).
The previous values, load profile, maximum demand and the
event log functions are only readable via bus.
Changing the default settings of these functions are only pos-
sible by serial communication.
If the time and date are not set no values will be registered.
If all the memory available for a time dependant function is
used, the oldest recorded data for that function will be overwrit-
ten. Changing interval length or number of values to be stored
for a function will reset all values stored.
Internal clock
The internal clock has a built in calendar and keeps automati-
cally track of leap year and daylight savings time (DST).
DST function is optional.
Backup of the clock during a power failure is provided by a
supcapacitor. The time is controlled from a quartz crystal based
real time clock. Time and date is set via the buttons or via com-
munications.
The internal clock is approved according to IEC 62052-21
and IEC 62054-21 which contains particular requirements for
time switches. The stated accuracy is less than 5 ppm at room
temperature when controlled from the quartz crystal based real
time clock.
Previous values
The monthly value feature will store all energy registers and
input counter values altogether with a date/time stamp upon a
change of day or month. All total energy values are stored and
in meters equipped with the tariff feature all the tariff registers
will also be stored. The number of stored monthly values can be
setfrom0to127.
Load profile
In the load profile function each day is divided into intervals of
a certain length where the energy consumption in each interval
is stored. The possible interval lengths are 15, 30 or 60 minutes.
The default value is 60 minutes.
The quantities that can be stored are active and reactive energy
with the number of pulses registered on input 1 and 2. Storage
of reactive energy is possible on combined meters only and
storing of pulses requires meters with corresponding input.
The load profile function always use standard time irrespective
if the DST (daylight savings time) function is active or not.
Maximum demand
In the maximum demand function the time is divided into inter-
vals of a certain length and the mean power in each interval is
measured and the maximum mean value is stored together with
a date/time stamp. The possible interval lengths are 15, 30 or
60 minutes and is programmable. Default value 15.
For each set of maximum demand values the end date/time
of the period is stored.
The quantities that can be stored are active and reactive power
and number of pulses registered on input 1 and 2 (pulses/in-
terval). In tariff meters the maximum demand is stored for each
tariff.
The maximum number of maximum demand values to be stored
areprogrammablefrom0upto127.
Event log
The event log function can log the following events:
•Overvoltageoneachphase(+6%)
•Undervoltagelevel1oneachphase(-10%)
•Undervoltagelevel2oneachphase(-15%)
•Phasevoltageoutage(-15%)
•Negativepower
•Totalpoweroutage
For the over- and undervoltage events a percentage level in
respect to a nominal voltage is given which is programmable.
For each registered event the start date/time and the duration
(in seconds) is stored.
The number of events to be stored are programmable from 0 up
to 255.