Transformer Ocp

[APPRENTICE1]

We Have A 300 Kva Transformer That Will Be Stepping Down The Voltage From A 15 Kv, @ 747.7 Amps Bus Down To 120/208v To Feed A (120/208v @ 1600 Amps Panel) Does Any One Have Any Ideas On How To Size The Overcurrent Protection For The Primary And Secondary Feeders On This (asap)

 

[billsnuff]

art 240.20 and art 450

 

[APPRENTICE1]

There Is Nothing That Relate

There Is Nothing That Relate

The Code Is Limited To Voltages Of 600v And Less But What About 15kv Transformations?

 

[billsnuff]

part IX 240.100 over 600 v

 

[don_resqcapt19]

The Code Is Limited To Voltages Of 600v And Less But What About 15kv Transformations?

There a number of Articles that have sections for over 600 volts. For the transformer you look at 450.3. There are tables their for both over and under 600 volts. The previous post gave you the section for conductor overcurrent protection for over 600 volts. Please note that you have to satisify the rules in both Article 450 and 240. The rules in 450 are for the transformer itself and the rules in 240 are for the conductors.