Low Voltage Breaker Trip Settings

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Shaneyj

Shaneyj

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Project Engineer
I have an RFI into manufacturer, but can you check my interpretation please?

Manual says
I1 = *1000A
t1 = 3s
I3 = 1,5x [1.5x]

*Based on 3 breaker options (1600A, 1200A, and 1000A) and their corresponding I1 percentages they all equal 1000A.
- Does that mean that the continuous is 1000A,
- With a long time trip setting of 3s,
- And an instantaneous of 1.5X (1500A)?

- What is the "N" column and what does 50% mean?



1640721416553.png

1640721440363.png

Thank you!
 
Original post from desktop PC. When viewed from my phone I noticed the pics don't show up.
Hopefully these will show on the mobile version.
 

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Where are the image clips from? Maybe in context of the breaker and the trip unit type we can provide better help.
It seems strange that it shows Qty, like it is a bill of material or something.
 
ron said:
Where are the image clips from? Maybe in context of the breaker and the trip unit type we can provide better help.
It seems strange that it shows Qty, like it is a bill of material or something.
Click to expand...
The images are from the manual for a Danfoss drive.
As the manual states, qty is 2 because the rectifier section has 2 diode bridges that require individual protection.
The pic of chart with the qty - all that is missing from the screenshot is model type (NXN 2000_6) - that's really all there is.
The columns on the right headed with "L", "I" and "N" - I assumed mean long-time, instantaneous, and neutral.
Of course I could be wrong but the L and the I seemed to make sense with my interpretation. Still not sure what N means...
Based on info I have gathered from tech specs of ABB breaker (ABB X1 Emax), it has trip settings for LSIG.
 
"N" would relate to the Neutral Trip setting, if any, meaning the Neutral would trip if it exceeds 50% of the In (rated) current of the breaker. If they are 4 pole breakers, that would be relevant. If there is no Neutral pole, it is not. We generally dop not use Neutral sensing here in North America, but they do elsewhere in the world.
 
Jraef said:
"N" would relate to the Neutral Trip setting, if any, meaning the Neutral would trip if it exceeds 50% of the In (rated) current of the breaker. If they are 4 pole breakers, that would be relevant. If there is no Neutral pole, it is not. We generally dop not use Neutral sensing here in North America, but they do elsewhere in the world.
Click to expand...
No neutral load in this application.
This manual was written in Finland. There have been a couple lost in translation statements that the vendor has clarified.
Thank you for the input.

Sent from my SM-G965U using Tapatalk
 
Shaneyj said:
No neutral load in this application.
This manual was written in Finland. There have been a couple lost in translation statements that the vendor has clarified.
Thank you for the input.

Sent from my SM-G965U using Tapatalk
Click to expand...
I've worked for two German companies, I spent a lot of time deciphering these kind of issues. I was always advocating for them to use terminologies and standards that we would recognize here. They could not have cared less; we were, in their words, insignificant in the wider world as far as they were concerned.
 
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