Grouch1980
Senior Member
- Location
- New York, NY
Hey all!
Always another question :?
So i'm looking at Time current curve for a 1,000 amp LSIG breaker that you'll see in the link below (it's the first curve / chart when you scroll down. i tried posting a pic instead, but it was coming out too small).
http://electrical-engineering-portal.com/6-adjustable-tripping-settings-circuit-breaker
What determines the slope of the line labeled 'long time delay i2t slope'? I understand the long time delay pickup is 12 seconds @ 6000 amps... but how do you determine the pickup time of 450 seconds at 1,000 amps? How do you calculate the 450 seconds? or does the slope give you this? if so, how do you calculate the slope? I'm pretty sure it's something easy that i'm not seeing.
Thanks again.
Always another question :?
So i'm looking at Time current curve for a 1,000 amp LSIG breaker that you'll see in the link below (it's the first curve / chart when you scroll down. i tried posting a pic instead, but it was coming out too small).
http://electrical-engineering-portal.com/6-adjustable-tripping-settings-circuit-breaker
What determines the slope of the line labeled 'long time delay i2t slope'? I understand the long time delay pickup is 12 seconds @ 6000 amps... but how do you determine the pickup time of 450 seconds at 1,000 amps? How do you calculate the 450 seconds? or does the slope give you this? if so, how do you calculate the slope? I'm pretty sure it's something easy that i'm not seeing.
Thanks again.
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