Why do we use 1.73 for three-phase?
In a three phase circuit, the use of the constant 1.732 results from the fact that not all three phases are producing the same amount of power at the same time. … Suffice it to say that the correct power from a three-phase system at any point in time is found by multiplying by the square root of 3.
How do you calculate 3-phase current?
For 3-phase systems, we use the following equation: kW = (V × I × PF × 1.732) ÷ 1,000. Again, assuming unity PF and solving this equation for “I,” you get: I = 1,000kW ÷ 1.732V.
How many ohms should a 3 phase motor read?
The reading should be between 0.3 to 2 ohms. If it is 0, there is a short. If it is over 2 ohms or infinite, there is an open. You can also dry the connector and retest to possibly get more accurate results.
How do you calculate the full load of a 3 phase motor?
For three-phase, full load current for the resistive load is equal to the three-phase power divided by 1.732 times of voltage. Here power factor will be unity for resistive loads. Full load current I, I =P.
How many amps does a 7.5 kW 3 phase motor draw?
Three Phase Motors
| MOTOR RATING | HP | APPROX. F.L.C. AT LINE VOLTAGE |
|---|---|---|
| 5.5 kW | 7.5 | 20 |
| 7.5 kW | 10 | 27 |
| 9.3 kW | 12.5 | 34 |
| 10 kW | 13.5 | 37 |
How many amps is a 3 phase?
If your calculator doesn’t have a square root function, use 1.73 as an approximation of the square root of 3. For example, a three phase circuit using 25,000 watts of power and a line voltage of 250 will have a current flow of 25,000/(250 x 1.73), which is equal to 57.80 amperes.