How To Calculate The Rating Of Single Phase & Three Phase Transformers In KVA
The power rating of a transformer is the maximum power it can deliver to the load.
It is expressed in kVA (kilovolt-amperes), which is the product of voltage and current in the transformer.
The rated power of a transformer depends on the number of phases, the primary and secondary voltage, and the primary and secondary currents.
To calculate the power of a single-phase transformer, the following formula can be used:kVA = (V x I) / 1000, where V is the voltage (in volts) and I is the current (in amps) on the primary or secondary side of the transformer.
For example, if you have a single-phase transformer with a primary voltage of 120 V and a primary current of 10 A, you can calculate its rating by multiplying 120 x 10 and dividing by 1,000.
The result is 1.2 kVA.To calculate the power rating of a three-phase transformer, the following formula can be used:kVA = (√3 x V x I) / 1000where √3 is the square root of 3 (approximately 1.732)and V is the phase voltage between the phases (in volts) and I is the line current (in amps) on the primary or secondary side of the transformer.
For example, if you have a three-phase transformer with a phase-to-line voltage of 480 V and a primary line current of 20 A, its rating can be calculated by multiplying √3 x 480 x 20 and dividing by 1000.
The result is 16.6 kVA.You can also use online calculators to find transformer ratings, such as E.g.[this](^5^).Just enter the number of phases, voltage, and current and you will get the kVA power.