I'm building a 800 amp single phase service with a 38000 AIC rating. I have an existing 400 amp fused disconnect with proper AIC rating. I am upgrading and adding a 200 amp fused disconnect with the proper AIC that feeds a 10000 AIC rated main lug panel 150' away. I will also have a 200 amp main breaker panel with a 38000 AIC rating with a subpanel adjacent to that, with a 10000 AIC rating. So the 400 amp disconnect, the 200 amp disconnect, and the 200 amp main breaker panel are the 3 main disconnects equaling in 800 amps. Is this all correct and AIC ratings?
AIC Rating
- Thread starter Rknrbn
- Start date
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Your breakers, in the main light panel need to be series rated with your200A fuses, which they likely are, or you need to calculated available fault current after your 150' of conductors.
Your fused disconnects will need to have Class R fuse clips, which should be easy to do
Your fused disconnects will need to have Class R fuse clips, which should be easy to do
MyCleveland
Senior Member
- Location
- Cleveland, Ohio
Your fourth sentence….
This 200A panel is at your service entrance point and one of three mains, yes?
You have it rated at 38k, did not know that was a thing 10,14,18,22,25,35,42,65 and up. Minor point, but my question is how do you justify the adjacent sub panel at 10k?
I assume you are feeding via CBer in your 200A panel.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
After 150 feet of conductor the available fault current at load end is likely under 10kA. Unless perhaps they are well oversized.
That is a little confusing. If there is another 10kA rated panel near the service entry that supposedly has 38kA available, it may need more attention to the details. Is possible if it has Class R fuse ahead of it it may be series rated though
Deltaforce
Senior Member
- Location
- India
- Occupation
- Electrical Engineer
If manufacturer not have a series rating the combination, you have issue
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
You have to make the calculation, you cannot go just with gut feel, whether it is 150' or 1.5'
Deltaforce
Senior Member
- Location
- India
- Occupation
- Electrical Engineer
He engage engineering software ETAP, SKM for that
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
For something like this, I would use a simple on-line Short Circuit Calculator or the spreadsheet one I created way back 10 the 80's using Lotus-123 based on the hand calculations I used in college.