Transformers

Question 1

Delta configurations

Answer 1

I line = I coil x 1.732

V line = v coil

Question 2

Wye configurations

Answer 2

I line = I coil

V line = v coil x 1.732

Question 3

Apparent power formulas

Answer 3

1 phase AP = V coil x I coil
3 phase AP = (V coil x I coil) x 3
3 phase AP = V line x I line x 1.732

Question 4

Transformer Turns Ratio, TTR calculations

Answer 4

1. Ratio of turns primary to secondary Np/Ns
2. Voltage ratings primary to secondary Vp/Vs
3. Current ratings secondary to primary Is/Ip

Question 5

The purpose of the TTR test is to confirm the measure ratio is ____ of the calculate or nameplate ratio

Answer 5

+- .5%

Question 6

What of the labeling for high voltage and low voltage coils?

Answer 6

High voltage coils H, low voltage X

Question 7

What are tertiary bushing terminals designated as?

Answer 7

Y

Question 8

What is the single phase apparent power formula?

Answer 8

V coil x I coil = AP

Question 9

When conducting a TTR test, what should you compare the readings to?

Answer 9

Nameplate