ITRON Centron, Техническое справочное руководство

Страница: 63 / 100

Operation: C12.19 C1SD, C1ST, and C1SL Versions
CENTRON® Meter Technical Reference Guide 53

All Maximum Demand values are reset to zero. All corresponding times and dates of
maximum demands are cleared (meters with timekeeping functionality only).

The number of demand resets is increased by one.

The number of in-service days since the last reset is set to zero.

The time and date of the last reset is updated (meters with timekeeping functionality
only).

The normal mode display resumes. Exception is when in Test Mode, the display
resumes with next item in display list.
As a security feature, a demand reset lockout time can be programmed to prevent additional
demand resets until the programmed time expires.
Cold Load Pickup
Normally, when power is restored to the meter after an outage, a new demand interval is
started and demand calculations begin immediately. The meter can be configured to
recognize a demand delay or cold load pickup (CLPU) time. If a CLPU is configured in the
meter, the meter will delay demand calculations for the configured amount of time (0 to 255
minutes in one-minute increments). For example, if a CLPU time of five minutes is
programmed into the meter, a power outage will cause the meter to wait five minutes after
power restoration before resuming demand calculations.
TOU/Load Profile Meters
All meters with timekeeping functionality have a battery installed. The battery allows the
TOU and Load Profile data, in RAM, to be maintained during a power outage. The battery
also allows the timekeeping circuitry in the meter to maintain the meter's clock during an
outage.
Upon the return of AC power, the register undergoes a procedure similar to the initial
power-up. The meter performs self-diagnostic checks, data is retrieved from non-volatile
memory, and normal operation is resumed. The amount of time, in minutes, the meter was
sustained by the battery during a power outage is added to the Time on Battery register.
Since the demand interval is synchronized to the top of the hour, the first demand interval
after a power outage may be shorter than the programmed interval value.
Self Reading and SnapShot Registers
All CENTRON C12.19 D/T/L meters are equipped with two snapshot registers. The
snapshot registers store self read data that was triggered by a demand reset. Snapshot 1
contains the most recent demand reset data. Snapshot 2 is the next most recent set of self
read data at demand reset. Meters with timekeeping functionality can store up to twelve self
reads when a self-read is performed. The first four self read registers are displayable in the
Normal and Alternate mode. The remaining 8 self read registers are viewable in the
PC-PRO+ Advanced software.