Schneider Electric PM820, PM870, PM810, PM850 manual Glossary, Terms, 63230-500-225A2 3/2011, 105

63230-500-225A2 3/2011

Glossary

Terms

accumulated energy—energy can accumulate in either signed or unsigned (absolute) mode. In signed mode, the direction of power flow is considered, and the accumulated energy magnitude may increase and decrease. In absolute mode, energy accumulates as a positive, regardless of the power flow direction.

active alarm—an alarm that has been set up to trigger, when certain conditions are met, the execution of a task or notification. An icon in the upper-right corner of the meter indicates that an alarm is active (!). See also enabled alarm and disabled alarm.

baud rate—specifies how fast data is transmitted across a network port.

block interval demand— power demand calculation method for a block of time. Includes three ways to apply calculating to that block of time; sliding block, fixed block, or rolling block methods.

communications link—a chain of devices connected by a communications cable to a communications port.

current transformer (CT)—current transformer for current inputs.

demand—average value of a quantity, such as power, over a specified interval of time.

device address—defines where the power meter resides in the power monitoring system.

disabled alarm—an alarm which has been configured but which is currently “turned off”; i.e, the alarm will not execute its associated task even when its conditions are met. See also enabled alarm and active alarm.

enabled alarm—an alarm that has been configured and “turned on” and will execute its associated task when its conditions are met. See also disabled alarm and active alarm.

PowerLogicTM Series 800 Power Meter Glossary

event—the occurrence of an alarm condition, such as Under-voltage Phase A, configured in the power meter.

firmware—operating system within the power meter.

fixed block—an interval selected from

1to 60 minutes (in 1-minute increments). The power meter calculates and updates the demand at the end of each interval.

float—a 32-bit floating point value returned by a register (see Register List on page 79). The upper 16-bits are in the lowest-numbered register pair. For example, in the register 4010/11, 4010 contains the upper 16-bits while 4011 contains the lower 16-bits.

frequency—number of cycles in one second.

line-to-line voltages—measurement of the rms line-to-line voltages of the circuit.

line-to-neutral voltages —measurement of the rms line-to- neutral voltages of the circuit.

maximum demand current—highest demand current measured in amperes since the last reset of demand.

maximum demand real power —highest demand real power measured since the last rest of demand.

maximum demand voltage—highest demand voltage measured since the last reset of demand voltage.

maximum demand (peak demand) —highest average load during a specific time interval.

maximum value—highest value recorded of the instantaneous quantity such as Phase A Current, Phase A Voltage, etc., since the last reset of the minimums and maximums.

minimum value—lowest value recorded of the instantaneous quantity such as Phase A Current, Phase A Voltage, etc., since the last reset of the minimums and maximums.

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