21kV Relay Coordination with Utility (PG&E)

[julesm]

Greetings -
I need to select coordination settings for a Basler BE1-51 between the PG&E SEL-251 and the (5) Cutler Hammer RBA-400 125E fuses for the 5 substation feeds.
I am confused by the info from the utility. Here is what I was given:

Relay = SEL-251
CTR = 1200/5
Ground: curve = VI, T = 1 (240 A), TD = 3, IT = 29 (6960 A)
Phase: curve = VI, T = 3 (720 A), TD = 4, IT = 29 (6960 A)

The coordination criteria is they need at least 0.35 seconds between their relay curves and PG&E's relay curves.

I am having trouble finding this specific device in my SKM library. Any ideas? I have not worked a lot in MV so any advice would be much appreciated, including what I can read to brush up in this area.
Best,

 

[davidbeach]

Any SEL relay in the SKM library should work. Or better yet download the relay manual and put the curves in yourself. Not that hard.

 

[JensenDrive]

SEL has never gotten into making a wide variety of relay curves. All their relays have the same 4 curves, though in the more recent years they added a set of IEC curves.

However, my copy of SKM has numerous versions of the 251 relay. If your maintenance fee is up to date, you know what to do.

 

[julesm]

Thanks for the response.
Any tips on good sources for MV substation design and review?
Thank You!

 

[davidbeach]

Check out faq238-1287.