Fused Switchgear in new installations

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mbrooke

mbrooke

Batteries Included
Location
United States
Occupation
Technician
How common is LV fused switchgear in new installations? Any idea of the cost vs breakers? Life cycle maintenance? Sizes I have in mind are 2000-4000amp bus and 600amp feeders, 277/480 volts.
 
It used to be more common when the fault current was high, because breakers couldn't cut it. But since Current Limiting Breakers have become the norm, I don't see it as much anymore. I don't think, with the new emphasis on Arc Flash safety, that we will see plants going in with one massive transformer and 100kA on the bus. The trend I'm seeing now is to segment the system into smaller chunks to keep the fault current as low as practical, which leans itself to breakers instead of fuses.
 
Jraef said:
It used to be more common when the fault current was high, because breakers couldn't cut it. But since Current Limiting Breakers have become the norm, I don't see it as much anymore. I don't think, with the new emphasis on Arc Flash safety, that we will see plants going in with one massive transformer and 100kA on the bus. The trend I'm seeing now is to segment the system into smaller chunks to keep the fault current as low as practical, which leans itself to breakers instead of fuses.
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Yahhh, you can say that again regarding segmentation. I've been doing it for a few years now in my designs. I felt comfortable feeding 480 volts all the way up to 4MVA and beyond... now I know better. Even things like malls and professional centers now get fed with 250-500kva padmounts all around the perimeter instead of two or four giant units in the basement or back mechanical mezzanine.
 
Jraef said:
It used to be more common when the fault current was high, because breakers couldn't cut it. But since Current Limiting Breakers have become the norm, I don't see it as much anymore. I don't think, with the new emphasis on Arc Flash safety, that we will see plants going in with one massive transformer and 100kA on the bus. The trend I'm seeing now is to segment the system into smaller chunks to keep the fault current as low as practical, which leans itself to breakers instead of fuses.
Click to expand...

Question- can fuses reduce arc flash? This has me intrigued :eek:



https://www.youtube.com/watch?v=3dckmSgp1nw
 
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