SL7000 User Guide
6.7.
Energy rate switching
The contract between the customer and the utility will usually specify how many energy rates are available and at
what times of the day these rates can be applied. These energy rate regimes are known as
tariffs
.
Tariffs are defined and downloaded to the meter using the meter support tool. New tariffs can be defined and
loaded at any time.
A tariff specifies a set of energy and demand rates for one energy quantity and only energy registers associated
with those rates are updated; all other energy registers are not modified. For billing purposes, each tariff is
associated to an energy cost.
The real-time clock and calendar enable the meter to perform Time-Of-Use (TOU) energy rate switching under
control of these programmable tariff regimes.
Note:
Tariff switching can also be achieved using external control signals.
6.7.1.
Daylight saving
The meter can be programmed to follow seasonally-based changes in local time, generally referred to as
Daylight Saving Time (DST) or Summer Time.
Where the facility is enabled, the meter clock times will be advanced and retarded automatically by up to 2 hours
each year.
The DST configuration can be defined in a number of ways to allow for use in both the Northern and Southern
hemispheres and accommodate the different rules that apply in different countries.
•
Generic
All the date parameters for the DST transitions are individually programmable.
•
Programmed
Specific dates of change for the DST transitions can be chosen for each year. Up to five years values can be
programmed in advance.
•
Generic with season
The individually programmable DST transition dates are linked to a pre-defined season value.
•
Programmed with season
The specific dates of change for the DST transitions are linked to a pre-defined season value.
6.7.2.
Seasons
The meter supports up to twelve seasons per year, for which different tariff regimes can be programmed. These
seasons are defined by start dates, which can be set individually or derived from programmed daylight saving
dates/times.
The start date of the first tariff season is always defined as 1st of January.
The following example illustrates four individually configured seasons:
Season
Starting Date
1
01/01
2
01/04
3
01/07
4
01/11
