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CET Inc.
4.3.4 Mains Current Alarms
PMC-512-D provides four Current alarm levels (High-High, High, Low, Low-Low) for the Mains Current.
The
Current Alarms
will only be evaluated if it’s determined that the
Current ON
status is true for the
Mains Meter. The Mains Current Alarms will only be evaluated if the
Mains Current Type
is
Incomer
.
The following table illustrates the Mains Current Alarms parameters.
Parameters
Description
Range/Default
Current HH Alarm Threshold (%)
Mains Current HH Alarm Threshold
0* to 100%
Current HH Alarm Time Delay
Mains Current HH Alarm Time Delay
0 to 9999(s), 10s*
Current H Alarm Threshold (%)
Mains Current H Alarm Threshold
0 to 100%, 0%*
Current H Alarm Time Delay
Mains Current H Alarm Time Delay
0 to 9999(s), 0s*
Current L Alarm Threshold (%)
Mains Current L Alarm Threshold
0* to 100%
Current L Alarm Time Delay
Mains Current L Alarm Time Delay
0* to 9999(s)
Current LL Alarm Threshold (%)
Mains Current LL Alarm Threshold
0*
to 100%
Current LL Alarm Time Delay
Mains Current LL Alarm Time Delay
0* to 9999(s)
Current Alarm Trigger
Mains Current Alarm Trigger
0*=Disabled, Bit 0=DO
Bit 1=Alarm LED
Bits 2-15=Reserved
Table 4-8 Current Alarm Parameters
For High and High-High Alarms, which are conceptually similar to Over Setpoint:
Return Threshold = Alarm Threshold x (1 – Universal Hysteresis)
For Low and Low-Low Alarms, which are conceptually similar to Under Setpoint:
Return Threshold = Alarm Threshold x (1 + Universal Hysteresis)
The following logic diagrams illustrates the different levels of Current Alarms.
Where
Current Alarm Limit = Mains’ Breaker Rating x Alarm Threshold (%)
Current Return Limit = Mains’ Breaker Rating × Return Threshold (%)
It should be noted that the absolute value of the Current Alarm Limit is calculated based on the
Breaker Rating parameters.
Therefore, it’s critical to set the Breaker Rating correctly for the Current
Alarms to work properly.
Current HH Alarm:
Figure 4-9 Current HH Alarm Logic Diagram