How to Calculate Three Phase Amps From Megawatts

3-phase designs support high-voltage power distribution systems
••• Brand X Pictures/Brand X Pictures/Getty Images

Megawatt 3 phase power applies primarily to large power distribution systems. In fact, the unit of watts represent the actual power used by system after a percentage of the power is lost due to inefficiencies of the load. Therefore, the total power supplied by the power supply is higher than the actual power and is in the form of volt-amperes, or in this case, Megavolt-amperes or MVA. You need to know the MVA to figure 3-phase amps. To figure MVA from megawatts, you need to know the power factor associated with the load, which measures the level of inefficiency of the load.

    Find the phase voltage, or "Vphase," associated with the 3-phase system. Refer to system specifications. For example, assume 4,000 volts, which is typical for power in the megawatt range

    Find the power factor, "pf," of the load powered by the megawatt power distribution system. Refer to specifications of the load. A typical power factor for 3-phase loads is 0.8.

    Find the total power delivered by the power distribution system in Megavolts-amperes or "MVA." Use the formula MVA = MW/pf where MW is the megawatt value of the system. For example, if MW is 20MW and pf is 0.8:

    MVA = 20/0.8 = 25 MVA

    Calculate 3 phase amps, or "I", using the formula: I = (MVA x 1,000, 000)/(Vphase x 1.732). The 1,000,000 represents "mega" where 1 megavolt is 1,000,000 volts. Continuing with the example:

    I = (25 x 1,000,000)/(4,000 x 1.732) = 25,000,000/6,928 = 3608.5 amps.

Related Articles

How to Calculate 3-Phase Line-To-Ground Voltage
How to Calculate Kva to Amp
How to Calculate Transformer VA Rating
How to Calculate Three Phase Amperage
How Do I Convert Amps to Kw 3 Phase?
How to Convert HP to Amps & Volts
How to Size a Transformer KVA
How to Calculate KVA From The Electric Bill
How to Convert Megawatts to Amps
How to Convert mW to mA
How to Calculate KVA from KW
How to Convert KVA to KW 3-Phase
How to Size an Overcurrent Device for a Transformer
How to Calculate DC Voltage
How to Calculate Cost of Electricity for Electric Motor...
Types of Electrical Loads
How to Calculate the Duty Cycle of a Frequency
How to Convert HP to KVA
How to Test a 3-Phase Motor With a Multi-Meter
How to Calculate Duct Airflow