EET PMC-D726M - Demand Measurements; Power Quality; Phase Angles

CET Electric Technology
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4.2.3 Demand Measurements
Demand is defined as the average power consumption over a fixed interval (usually 15 minutes) based
on the sliding window method. The PMC-D726M provides the following Demand and Peak Demand
measurements since Firmware V1.00.04 (LED)/V1.01.04 (LCD):
Present Demands
Ia, Ib, Ic
kW Total, kvar Total, kVA Total
Peak Demands
Ia, Ib, Ic
kW Total, kvar Total, kVA Total
Table 4-4 Demand Measurement
All Demand parameters can be retrieved through communications for both versions. Only Present
Demands can be accessed via the Front Panel of the LCD version but not the LED version.
The PMC- D726M provides the following Demand setup parameters:
Setup Parameter
Definition
Options
Demand Period
1 to 60 minutes. For example, if the # of Sliding Windows is
set as 1 and the Demand Period is 15, the demand cycle will
be 1×15=15min.
1 to 60 minutes
Default=15
# of Sliding
Windows
Number of Sliding Windows.
1 to 15
Default=1
Self-Read Time
The Self-Read Time allows the user to specify the time and
day of the month for the Peak Demand Self-Read operation.
The Self-Read Time supports three options:
 A zero value means that the Self-Read will take place at
00:00 of the first day of each month.
 A non-zero value means that the Self-Read will take place
at a specific time and day based on the formula: Self-Read
Time = Day x 100 + Hour where 0 ≤ Hour ≤ 23 and 1 ≤ Day
≤ 28. For example, the value 1512 means that the Self-
Read will take place at 12:00pm on the 15th day of each
month.
 A 0xFFFF value will disable the Self-Read operation and
replace it with manual operation. A manual reset will
cause the Max. Demand of This Month to be transferred
to the Max. Demand of Last Month and then reset. The
terms This Month and Last Month will become Since Last
Reset and Before Last Reset.
Default=0xFFFF
Table 4-5 Demand Setup
4.3 Power Quality
The PMC-D726M provides the following Power Quality parameters since Firmware V1.00.04
(LED)/V1.01.04 (LCD).
 Phase Angles
 Harmonics (THD, TOHD, TEHD, HD02~HD31)
 TDD
 K-Factor
 Crest Factor
 Unbalance
All of above Power Quality parameters can be accessed through communications. Only Voltage/Current
Unbalance and 3-Phase Voltage/Current THD can be retrieved via the Front Panel of the LCD version.
4.3.1 Phase Angles
Phase analysis is used to identify the angle relationship between 3-phase Voltages and Currents.
For WYE connected systems, the per phase difference of the Current and Voltage angles should