240V high-leg fault current values from POCO

[necnotevenclose]

It's been a while I hope everyone is doing well

I requested the POCO provide the available fault current on the secondary side of a 240V high leg transformer. They came back with two values which I haven't run into before. Value 1 @ 120V is 40kA, value 2 @ 240V is 30kA.

The main distribution gear will be 3-phase MLO with 2-pole & 3-pole breakers. Since we are connecting a 3-phase system do I use value 2?

Thanks in advance for your response.

 

[ptonsparky]

It's been a while I hope everyone is doing well

I requested the POCO provide the available fault current on the secondary side of a 240V high leg transformer. They came back with two values which I haven't run into before. Value 1 @ 120V is 40kA, value 2 @ 240V is 30kA.

The main distribution gear will be 3-phase MLO with 2-pole & 3-pole breakers. Since we are connecting a 3-phase system do I use value 2?

Thanks in advance for your response.

What happens with the L-G fault that you have some day?

 

[necnotevenclose]

thank you Sparky. Initially when I looked at Bussman's calc, I thought I was to apply the fault current based on if I'm connecting either a L-L or L-G OCPD. Going back it's apparent you need to perform both calcs to determine the worst case calculated fault. Which in my case would be L-G.