What happens when 3 phase system is not balanced?

What happens when 3 phase system is not balanced?

Phase unbalance of a three-phase system exists when one or more of the line-to-line voltages in a three-phase system are mismatched. The unbalanced voltages cause unbalanced current in the motor windings; unbalanced currents mean an increase of current to at least one winding raising that winding temperature.

What is equation for KW in case of unbalanced loads?

IL =KW/√3VL. For delta connection it is IL = √3 × I/ph. Now in case of unbalanced load , IR +IY+IB = 3I0.

What is the maximum current unbalance of a 3 phase motor?

RE: Acceptable current unbalance in three-phase motor NEMA MG1 standard gives a maximum allowable voltage imbalance of 1\%. If current imbalance exceeds 10\%, the motor must be derated.

How do you calculate the power of an unbalanced load?

Unbalanced Three Phase : How to calculate total power?

1. the line to neutral (phase) voltage VLN = 208/√3 = 120 V.
2. phase 1 apparent power = 42 x 120 = 5040 VA = 5.04 kVA.
3. phase 2 apparent power = 84 x 120 = 10080 VA = 10.08 kVA.
4. phase 3 apparent power = 80 x 120 = 9600 VA = 9.6 kVA.

How do you calculate 3 phase unbalanced load?

How do you calculate phase unbalanced?

How to calculate voltage unbalance

1. Determine the voltage or current average.
2. Calculate the largest voltage or current deviation.
3. Divide the maximum deviation by the average voltage or current and multiply by 100 \% unbalance = (Max deviation from average V or I/average V or I) x 100.

How do you calculate percent imbalance?

Percent unbalance = (largest unbalance divided by average volts) x 100. Percent unbalance = (5.33 ÷ 221.33) x 100. Percent unbalance = 2.4 percent. As mentioned earlier, a voltage unbalance exceeding more than 2 percent in a three-phase system can cause excessive current unbalance among the windings.