User's Manual

ANSI Electric Meter v3.1 User’s Guide 53
power level setting, in watts, at which the load disconnect contactor will turn off.
This value is the sum of all 3 phases in a polyphase meter. The minimum value is
1,000 and the maximum is 72,000. As an example, a setting of 27,600 watts equals
40 amps per phase at 230 volts in a three-phase meter.
Switching the Maximum Power Level Thresholds
The meter can be programmed to switch from Primary Power Level Threshold to the
Secondary Power Level Threshold at a specific time. If the start time specified has
already passed, the switch will occur immediately.
The switch can be programmed to last indefinitely, or it can be programmed to last
for a specific switch duration which can be set in minutes. If a switch duration is
specified, the meter will use the Secondary Power Level Threshold for that duration
before automatically switching back to the Primary Power Level Threshold.
This section provides additional information describing the behavior of the meter
when switching between the two power level thresholds:
1. The meter tracks the switch duration across power outages. For example,
consider a case where the meter receives a switch command at 8:00 A.M. with
a start time of 9:00 A.M. and a switch duration of 4 hours. If a power outage
occurs at 10:00 A.M. and power is not restored until 11:00 A.M, then the meter
will still switch back to the Primary Maximum Power Level Threshold at 1:00
P.M.
2. The meter honors the start time of the switch in the event of a power outage.
In this example, the meter receives a command at 8:00 A.M. to perform a
switch at 9:00 A.M. with a switch duration of 4 hours. If a power outage occurs
at 8:30AM and power is restored at 9:30AM, the meter will switch power level
thresholds as soon as power is restored, and will switch back at 1:00 P.M, as
initially scheduled.
3. If the start time for a switch has already passed when the meter receives the
command, the meter will not prorate the switch duration for the difference
between the requested start time and the time the command was received.
The meter will evaluate at the new power level threshold for the entire switch
duration. For example, if the meter receives a command at 8:00 A.M. with a
start time of 7:00 A.M. and a switch duration of 4 hours, the switch will still
last 4 hours, and the meter will switch back to the Secondary Maximum Power
Level at 12:00 P.M.
4. If the meter receives a new switch command while it is already using the
Secondary Maximum Power Level Threshold or has a pending start time to
switch to the Secondary Maximum Power Level Threshold, the meter will
disregard the previous command and follow the instructions of the new switch
command. This results in the following 4 possible scenarios:
Old
Command
New
Command
Comments
In the future In the future The parameters of the new command replace those of the old command.
The meter acts as if the old command never existed.
In the future In the past The meter behaves as if the old command never existed. The meter
immediately switches to Secondary Maximum Power Level Threshold,