SMS ISKRA MT375 - Real-time Clock (RTC); Time-of-use Registration; Maximum Demand

Mx37y_Technical_Description_ENG_v2.00.doc
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Mx37y
─ Single- and three-phase electronic meters with built-in DLC
modem, GSM/GPRS modem or RS485 comm. interface
which two are reserved for time and meter status.
The remaining objects are used for registering energy
by tariffs:
• Values of energy registers by tariffs depending
on the set saving period
• Meter status
Data in a load-profile recorder are accompanied with
a time stamp and with the meter status in the last
saving period as well as with a check sum. The time
stamp indicates the end of a registration period.
Capacity of the load-profile recorder 1:
Capture
objects
1 2 3 4 6 8
Number
of records
33696 19680 13536 10464 7104 5472
Legend:
Capture objects are without a clock and a status register
A number of records represents profile entries.
Capacity of the load-profile recorder 2:
Capture
objects
1 2 3 4 6 8
Number of
records
190 140 132 103 81 67
Legend:
Capture objects are without a clock
A number of records represents profile entries.
4.2.2. Log-book
Meters can register up to 128 events and meter
status in a log-book which is organized as a FIFO
memory. In this way, the last 128 events and meter
status are always available. The following events and
meter status can be registered:
• Meter fatal error
• Billing reset of the meter
• Time setting of the real-time clock
• Voltage failure
• Voltage re-establishing in the network
• Erased registers of the load-profile recorder
• Erased registers of the log-book
• Phase voltages failure (L1, L2, L3)
• Phase voltages re-establishing (L1, L2, L3)
• Opening of the meter and the terminal covers
• No connection timeout (only DLC meters)
• Prepayment token entry successful
• Prepayment token entry failed
• Prepayment credit expired
• Prepayment emergency credit expired
• Prepayment emergency credit activated
4.2.3. Keeping of billing results
The meter keeps billing results (energy and demand
v
alues registered by tariffs) in two billing profile, i.e. a
billing profile (billing profile 1) and a capture object
profile (billing profile 2).
The billing profile is used for storing billing registers
(data banks), and is actuated by billing actions. A
billing profile buffer is a place intended for data
banks. By default, the first register in a data bank is
time mark (0-0:1.0.0).
Billing profiles 1 and 2
Number of
registers
2 4 6 8 10
Profile
entries
49 36 29 24 20
4.3. Real-time clock (RTC)
A real-time clock involves an internal calendar that
assures information on year, month, day, day in a
week, hour, minute, second and leap year. The clock
accuracy should comply with the IEC 62052-21
standard for time switches.
A super capacitor (super-cap) is used as an auxiliary
power supply for surmounting longer power failures
(up to 10 days). For a complete charging of the super
capacitor the meter should be connected to network
voltage for at least 35 minutes. The clock is driven by
a crystal with 32.768 kHz frequency.
Option:
For longer failures up to two years long a Lithium
battery (3.6 V, 1 Ah, 1/2AA) is applied. A battery is
available only for Mx372 RS485 meter.
4.3.1. Time-of-use registration
The meter enables registration of energy and power.
Up to four tariffs (8 tariffs is an option) for power and
energy can be registered. Tariff changeover is
defined with hour and minute. Minimal resolution
between changeovers is one minute.
The real-time clock enables complex daily and
weekly tariff structures, as well as a couple of
seasons in a year.
Different combinations of the tariff program are
avaliable:
• Up to 4 tariff rates (8 rates as an option)
• Up to 4 seasons
• Up to 4 day types (8 as an option)
• Up to 8 individual changeovers inside individual
daily program
• Up to 32 programmable holidays
• Support to lunar holidays in compliance with
the Gregorian calendar.
4.3.2. Maximum demand
The real-time clock generates a demand period.
D
emand is calculated as an average value over the
demand period. The following demand periods can
be set in the meter: 15, 30 and 60 minutes. At the
end of the demand period, calculated demand value