In (or Iu) vs Ir Long Time Pickup

Electrical Testing Talk Relay Testing
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I’m a little confused with this breaker. I’m familiar with In meaning that you set the breaker long time pickup at a percentage of its maximum. And then you can set a time delay on the long time pick up as well. However I don’t understand why they have both In and Ir and the manual says the both of these are for setting long time pick up. I’d include a link to the manual but they don’t let me on the forum.

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Looks like its an additional multiplier for the rating plug but its hard to tell. My guess is that if you had a 1600A Plug for example you could use the first multiplier to dial that down to 800A. The second multiplier would be the pickup as normal. In this example, if set to 1 would be 800A, 0.5 would be 400A.

Why would you need this, I’m not sure but maybe it allows you to use different rating plugs in an emergency without changing the second pickup setting? I’ve never encountered this type of breaker before, I’m interested in learning more if you could post some additional info on the breaker and trip unit model.

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Ln: trip plug rating
Lr: frame rating of breaker

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