Electrical Load Sizing: UPS, Transformers, DG Sets and APFC Panels
Size a UPS, transformer, DG set or APFC panel from a schedule of connected loads.
What these calculators are for
Four calculators in Electrical & Power Engineering size
equipment from a list of the loads it will serve. Each builds the same total
from your equipment rows, converts it to kVA (or kVAR), adds a margin for
future growth and picks the next standard rating.
The connected-load rows
All four calculators take a Connected Loads (Equipment)
schedule. Add one row per type of equipment with Add
Equipment (web) or Add Row (mobile):
Equipment name — up to 100 characters.
Nof equipment — how many of this item.
Connected load — the load of one item.
Load factor — 0.4 to 1.
Each row contributes number × connected load × load factor; the
rows are added to give the total load in kW.
Connected load units. Each row’s unit selector offers
KW, HP, W and MW, and the load is converted to kW before it is added (1 HP =
0.7457 kW). The unit selector is for real power only; for a load rated in kVA,
multiply by its power factor and enter the kW.
A row with a problem (for example a name over 100 characters) stops the
calculation with a message naming the row and the field. Nothing is saved
until every row is val…