Given the transformer capacity, the rated current of its voltage grade side is calculated.

Description: applicable to any voltage level.

Formula: capacity divided by voltage is divided by six divided by ten.

Example: apparent current I= apparent power S/1.732*10KV=1000KVA/1.732*10KV= 57.736a

Estimate I = 1000 kva / 10 kv * 6/10 = 60 a

Electrician's formula (3)

Rough method to check the accuracy of low-voltage single-phase watt-hour meter:

Connect a 100 watt bulb, close the switch and time it.

Time and count revolutions at the same time. Record the value of six minutes per revolution.

The meter dial has a number of kilowatt-hour disk revolutions.

The value shrinks by 100 times, roughly equal to the number of records.

Electrician's formula (iv)

Given the capacity of three-phase motor, calculate its rated current.

Formula: capacity divided by kilovolts, quotient factor point 76.

We know three phase 222, kilowatt three point five amperes.

1 kw present 0.22 KV * 0.76 material 1 a

We have a three kilovolt motor, four kilowatts per ampere.

4 kw present 3 kv * 0.76 material 1 a

Note: the formula is applicable to the calculation of rated current of three-phase motor of any voltage grade. When the formula is used, the unit of capacity is kW, the unit of voltage is kV, and the unit of current is A.