UPS
The UPS component has two versions, 3Ph + N and 1Ph + N. A UPS cannot be inserted directly after a Source and it needs a distribution node to get connected. UPS component supports Multiple Sources feature and it can also be used to model multiple UPS running in parallel, see Multiple UPS Scheme.
Circuit edit tab of a UPS has a UPS section instead of a Load section, where the user can define various parameters related with the UPS.
Total UPS Apparent Power: This is where the user set the apparent power in kVA of the UPS being modelled. If the connected load is heigher than the apparent power of the UPS, ElectrcialOM will warn the user.
UPS Rating/Unit: This field is calculated by ElectricalOM automatically, and it indicates the rating of the UPS in amperes per phase.
UPS Charging Current/Unit: This field is used to define a current value for any charging current required for the UPS. This value will be added to the connected load value to estimate the design current of the UPS circuit. If Capacitor based charging option is enabled (see below), then, this will be automatically calculated by ElectricalOM.
Apart from above parameters, the user may also modify some advanced settings using the Settings... button under the UPS symbol.
Full load AC to AC efficiency: This is the efficiency of the UPS at full load. As the efficiency decreases, design current will increase.
Harmonics: The user can also define any harmonics generated by the UPS using the Harmonics field. This will be used to calculate any Neutral current which may appear due to harmonics. It should be noted that the harmonics will be caused by the charging current only and not by the load.
Output Phase: It is possible to set a 3Ph UPS as a 3Ph(input)-3Ph(output) or as a 3Ph(input)-1Ph(output) by selection the appropriate option. This option will be available only if the UPS is a 3Ph component and no 3Ph circuits is connected. ElectricalOM will require the user to click on Apply changes button to reflect the changes to the model.
When a 3Ph UPS is set as 3Ph-3Ph and if the load is not balanced, then, the rating of the circuit with greater power rating will be reflected to all of the input phases.
However, if a 3Ph UPS is set to 3Ph-1Ph mode, then, the total downstream power will be equally divided among the three input phases.
Capacitor based charging mode: If this box box is ticked, ElectricalOM will calculate the charging current automatically. ElectricalOM will deduct the connected load current from the UPS rating and set the remaining value as the charging current for UPS. As the user add new loads to the UPS, the charging current will decrease as long as the UPS rating is fixed.
