BTW LRD05 is a TM overload!
the frame size does not relate to instantaneous trip currents.Let me re-phrase my problem:To avoid confusion, let's take a large motor for which we can only use MCCB (not MCB). let's say 110 kW DOL motor. The Schneider's recommended combination is: magnetic only breaker (NSX250HMA220) plus contactor (LC1F225) plus overload (LRD05.)
The motor FLC is 200A, and let's assume the starting current is 1000A.
Now here is my problem:
How can I set the magnetic trip to 1000A, while the maximum breaker frame size is 250A?
hmmm they have 110 for single phase 3 phase no ideaLoyal comes from America is this going to make a difference to what circuit breaker is needed?
Missed that!!! Wet FishLoyal comes from America is this going to make a difference to what circuit breaker is needed?
It is a bit late, i was referring to an earlier post that mentioned fitting a 50A breaker. You mentioned Zs has not come into it, but it should, baring in mind this sounds like a industrial job where the motor may be a fair distance away from the distribution.S&S,Sou've confused me a little with this, not difficult especially at this time of night!
Zs has not come into it!
We were talking about TM O/L settings in the starter.
Also, for large motor supplies they may come from bus bar systems, & the OP was talking about MCCB's.
These require a MUCH lower Zs than even a D curve 60898.
Sorry buddy, not sure where you wre going with that?
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