# A (50/60 Hz) Transformer. Which one will give more Output? (When operates on 50 or 60 Hz frequency)

## A (50/60 Hz) Transformer. Which one will give more Output?

A Transformer is designed to be operated on both 50 & 60 Hz frequency. For the Same rating, which one will give more out put; when,

1.  Operates on 50 Hz
2.   Operates on 60 Hz

Obviously! It will give more out put when we operate a transformer (of same rating) on 50 Hz instead of 60 Hz.

Because in previous posts, we proved that, in inductive circuit, when frequency increases, the circuit power factor decreases. Consequently, the transformer out put decreases.
Let’s consider the following example.
Suppose,
When Transformer operates on 50 Hz Frequency
Transformer = 100kVA, R=700, L=1.2 H, f= 50 Hz.
XL = 2πfL = 2 x 3.1415 x 50 x 1.2 = 377 Ω
Impedance Z = √ (R2+XL2) = √ (7002+ 3772) = 795 Ω
Power factor Cos θ = R/Z = 700/795 =0.88
Transformer Output (Real Power)
kVA x Cos θ
100kVA x 0.88
88000 W = 88kW
Now,
When Transformer operates on 60 Hz Frequency
Transformer =100kVA, R=700, L=1.2 H, f= 60 Hz.
XL = 2πfL = 2 x 3.1415 x 60 x1.2 = 452.4 Ω
Impedance Z = √ (R2+XL2) = √ (7002+ 452.4 2) = 833.5 Ω
Power factor = Cos θ = R/Z = 700/833.5 =0.839
Transformer Output (Real Power)
kVA x Cos θ
100kVA x 0.839
=83900W = 83.9kW Output
Now see the difference (real power i.e., in Watts)
88kW- 83.9kW = 4100 W = 4.1kW
If we do the same (As above) for the power transformer i.e, for 500kVA Transformer, the result may be huge, as below.
(Suppose everything is same, without frequency)
Power Transformer Output (When operates on 50 Hz)
500kVA x 0.88 = 44000 = 440kW
Power Transformer Output (When operates on 60 Hz)
500kVA x 0.839 = 419500 = 419.5kW
Difference in Real power i.e. in Watts
440kW – 419.5kW = 20500 = 20kVA

### Electrical Technology

1. Anonymous says:

Wrong unit in the last row!<br />440kW – 419.5kW = 20500W = 20kW

1. Electrical Technology says:

20500W … We assume that 20.5kVA = 20kVA … for calculation purpose only ….

2. Rajasekar says:

How to calculate the induction value resistance value and amps value of transformer and how calculate the winding turns based on voltage

3. Anvekar Nikita Narsinha says:

Thanks to give basic and extra knowlege.

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