UPS Data

This dialog box includes the following areas and tabs:

See Common Tabs for information on the Location, Comments, Hyperlinks, or Collected Data tabs.

Figure 1: UPS Data Dialog Box

Figure 2: UPS Short Circuit Output Settings for IEC

Connection Information

Option Description
ID Name

Uniquely identifies the equipment item. The program automatically assigns a name, but you can change it, if needed. The name can be up to 16 characters long.

For uninterrupted power supplies, the program automatically assigns the names UPS-1, UPS-2, UPS-3, and so on.

Input Bus

The ID name of the bus connected to the input branch. The bus voltage determines the input voltage rating of the UPS.

Output Bus

The ID name of the bus connected to the output branch. The bus voltage determines the output voltage rating of the UPS.


The phase of the item. Currently, this is for reference only.

Specifications Tab

Option Description
UPS kVA kVA rating of the UPS.
X/R X/R ratio used for short circuit calculations at the output.
Short Circuit Output
½ Cycle / Initial
  • ANSI: Short circuit contribution at 1/2 cycle (momentary).
  • IEC: Short circuit contribution for initial current.

The value is entered as a multiple of the kVA rating.

Example: A 500kVA/0.48kV UPS has a momentary short circuit contribution of 3000Amps. The short circuit capability in multiples of kVA rating is 4.988 (~5.0). [ multiple = sqrt(3)*3kA*0.48kV/500kVA.]

Interrupting / Breaking
  • ANSI: Short circuit contribution at 5 cycles.
  • IEC: Short circuit contribution for breaking current.
30 Cycle / Steady State
  • ANSI: Short circuit contribution at 30 cycles.
  • IEC: Short circuit contribution for steady state current.

Power Flow Tab

Figure 3: UPS Data Power Flow tab

Option Description
% Efficiency Efficiency of UPS in delivering active power to load. When there is no battery charging, input active load is equal to output active load divided by efficiency.
% Battery Charging Power consumed in charging battery, expressed as percentage of Rated kVA of UPS.
Input PF Power factor of input.
Ctrl kV PU The per unit output voltage of the UPS, which the UPS tries to maintain.
Ctrl Angle The output voltage angle of the UPS, which the UPS tries to maintain.

Harmonics Tab

Use the Harmonics tab to indicate whether this equipment item is introducing harmonics into your power system.

Figure 4: Harmonics Tab

Option Description
Load Type

The default is Linear, indicating the equipment does not produce harmonics. Choosing Harmonic makes the item an harmonic source and makes other fields in this tab available to edit.

Note: For an adjustable frequency drive (AFD), the Load Type is always Harmonic.
For motors, the Load Type is Harmonic if the With Adjustable Frequency Drive (AFD) check box is selected on the Specifications tab of the motor; otherwise, it is always Linear.

Fundamental Amps

Use to set the fundamental amps. The options are as follows:

  • Equipment Rating sets Fundm Amps to the equipment rating of the item described in the Specifications tab. 
  • User Specified activates the Fundm Amps field, enabling you to specify a value. 

To use fundamental current calculated by power flow, select Calculated from Power Flow in the Summation Fundamental Voltage area of the Harmonics Options > Control dialog box.

Harmonic Spreadsheet

Use the spreadsheet to enter the harmonic spectrum produced by this item. You can enter up to 30 different harmonics in each equipment item. In the spreadsheet, enter the Harmonic Number (such as 5 for the 5th harmonic), the Harmonic Current in percent of the Fundamental Amps, and the Current Angle. By indicating the current angle, you can simulate transformer phase shift effects on rectifiers so appropriate canceling can take place. The harmonic may be integer or non-integer.

Library Load

Common harmonic spectra may be entered from the device library. For instructions on how to enter your own spectra information, see Harmonics with Spectrum™. After selecting a particular device library spectrum from the Mfr and Type lists, click Import, and that spectrum is entered into the harmonic spreadsheet.

Resistance Factor

EasyPower offers two methods for calculating RH:

  • Resistance varying with a power of the harmonic (R-EXP):
  • RH = RFund * H R-EXP

  • Resistance varying with a percent eddy current factor (%ECF):
  • RH = RFund * (1+ECF*H2)/(1+ECF)

EasyPower defaults all skin effect correction to R-EXP and a value of 0.5.

Typical Resistance Correction Factors




















Other Tabs

See Common Tabs for information on the Location, Comments, Hyperlinks, or Collected Data tabs.

More Information

Database Technical Reference Common Tabs
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Help was last updated on 3/22/2019