Search results
Results from the WOW.Com Content Network
A line-interactive UPS maintains the inverter in line and redirects the battery's DC current path from the normal charging mode to supplying current when power is lost. In a standby ("off-line") system the load is powered directly by the input power and the backup power circuitry is only invoked when the utility power fails.
A typical electrical generator rating plate contains the following parameters: [4] power rating is specified in terms of apparent power (KVA or MVA), since the exact power factor will be determined by the external factors; [5] power factor (PF) is the nominal power factor for other ratings; usually PF = 0.8; [5]
A common prefixed derived unit is "kilovolt-ampere" (symbol kVA). The VA rating is limited by the maximum permissible current, and the watt rating by the power-handling capacity of the device. When a UPS powers equipment which presents a reactive load with a low power factor, neither limit may safely be exceeded. [4]
Nameplate capacity, also known as the rated capacity, nominal capacity, installed capacity, maximum effect or gross capacity, [1] is the intended full-load sustained output of a facility such as a power station, [2] [3] electric generator, a chemical plant, [4] fuel plant, mine, [5] metal refinery, [6] and many others.
At low values of power factor, more apparent power needs to be transferred to get the same real power. To get 1 kW of real power at 0.2 power factor, 5 kVA of apparent power needs to be transferred (1 kW ÷ 0.2 = 5 kVA). This apparent power must be produced and transmitted to the load and is subject to losses in the production and transmission ...
In the power systems analysis field of electrical engineering, a per-unit system is the expression of system quantities as fractions of a defined base unit quantity. . Calculations are simplified because quantities expressed as per-unit do not change when they are referred from one side of a transformer to t
Current events; Random article; About Wikipedia; ... These sizes are grouped by rated current and power. [1] [2] NEMA size
For example, a fixed boost would be used when connecting equipment rated for 230 V AC to a 208 V power source. Units are rated in volt-amperes (most commonly, kilo-volt amperes KVA) (or more rarely, amperes) and are rated for a percent of voltage drop or rise. For example, a buck–boost transformer rated at 10% boost will raise a supplied ...