Allen-Bradley SMC-50 User Manual

128 Rockwell Automation Publication 1560F-UM001A-EN-P - June 2019
Chapter 5 Metering
Table 37 - Metering Parameters Associated with THD
Line Frequency
The SMC-50 control module measures and displays the system 3-phase AC Line
Frequency. Upon power up, the Line Frequency parameter displays zero until a
valid AC Line Frequency is measured. When three-phase power is removed from
the controller, the parameter maintains the value of the previous frequency
reading.
Table 38 - Metering Parameters Associated with Line Frequency
Current Imbalance
The SMC-50 control module provides a calculated Current Imbalance value.
The Current Imbalance calculation is equal to the largest deviation of the three
RMS phase current signals from the average RMS phase current, divided by the
average. Note that the controller Power Pole Current is used for the Current
Imbalance calculation.
Table 39 - Metering Parameters Associated with Current Imbalance
Parameter Number Name/Description Min/Max Value Default Value Access Units
35 THD V
a
0.0…1000.0 0.0 R %
36 THD V
b
37 THD V
c
38 THD V
ave
39 THD I
a
40 THD I
b
41 THD I
c
42 THD I
ave
Parameter Number Name/Description Min/Max
Value
Default
Value
Access Units
224 Line Frequency 0…100 0 R Hz
Parameter Number Name/Description Min/Max Value Default
Value
Access Units
295 Current Imbalance 0…100 0 R %

Allen-Bradley SMC-50 Specifications

General

Brand	Allen-Bradley
Model	SMC-50
Category	Controller
Language	English