The 3phase motor with 400v,7.46w power factor 0.8 runs with 85 percent efficiency calculate the line current?

To calculate the line current, we first need to calculate the apparent power (S), which is given by the formula:

S = P / power factor

Where P is the real power, which is given as 7.46 kW.

S = 7.46 kW / 0.8
S = 9.325 kVA

Next, we calculate the input power (Pin) using the formula:

Pin = S / efficiency

Pin = 9.325 kVA / 0.85
Pin = 10.97 kVA

Now, we can calculate the line current (I) using the formula:

I = Pin / (√3 * V)

Where V is the line voltage, which is given as 400V.

I = 10.97 kVA / (√3 * 400V)
I = 10.97 kVA / 692.82
I = 15.83 A

Therefore, the line current is approximately 15.83 A.

Given:

- Motor power: 7.46 kW
- Power factor: 0.8
- Efficiency: 85%
- Voltage: 400 V
- Phase: 3

Steps to calculate the line current:

1. Calculate the motor input power (Pin):

Pin = Power / Efficiency
Pin = 7.46 kW / 0.85
Pin = 8.78 kW

2. Calculate the motor apparent power (S):

S = Pin / Power factor
S = 8.78 kW / 0.8
S = 10.98 kVA

3. Calculate the phase current (Ip):

Ip = S / (√3 - V - Power factor)
Ip = 10.98 kVA / (√3 - 400 V - 0.8)
Ip = 14.6 A

4. Calculate the line current (Il):

Il = √3 - Ip
Il = √3 - 14.6 A
Il = 25.2 A

Therefore, the line current for the motor is 25.2 A.