Table 2-5 - Minimum Data Scalar Settings - Emerson 56WM WirelessHART SensEnable Reference Manual

Reference Manual
The table below are the minimum recommended scalar settings based on current transformer size.

Table 2-5 - Minimum Data Scalar Settings

Current Transformer
Size or Max Amperage
To determine the appropriate data scalar for an application, use the following formula:
Measured or Calculated Values / Data Scalar Value ≤ 65,535 (Register Value)
If the data scalar is too low, the data may be inaccurate. If the data scalar is too high, the significant
digits after the decimal are removed. Below is an example of how to calculate the appropriate data
scalar.
Example 1:
Voltage = 480V
▪
Amperage = 100A
▪
Total System Power = (480V) * (100A) * 3 = 144kW
▪
Select Data Scalar = 2, therefore data scalar value is 0.01
▪
Register Value = 144kW / 0.01 = 14,400
▪
Check 14,400 ≤ 65,535: Yes this data scalar is correct.
▪
Example 2:
Voltage = 480V
▪
Amperage = 1000A
▪
Total System Power = (480V) * (1000A) * 3 = 1,440kW
▪
Select Data Scalar = 1, therefore data scalar value is 0.001
▪
Register Value = 1,440kW / 0.001 = 1,440,000
▪
Check 1,440,000 ≤ 65,535: No this data scalar is incorrect.
▪
Change the data scalar value and check result again.
▪
240 Volts
50 Data Scalar = 1
100 Data Scalar = 2
200 Data Scalar = 2
400 Data Scalar = 2
600 Data Scalar = 2
1000 Data Scalar = 3
3000 Data Scalar = 3
3-Phase System Voltage
480 Volts
Data Scalar = 2
Data Scalar = 2
Data Scalar = 2
Data Scalar = 2
Data Scalar = 3
Data Scalar = 3
Data Scalar = 3
December 2017
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