Alwayslearningelec
Senior Member
- Location
- NJ
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- Estimator
A 16000AT drawout breaker feeding a 1200A ATS which feeds a 200a dist panel? If not , why? THanks
:grin:
:grin:
Does this make sense
- Thread starter Alwayslearningelec
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hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
A 16000AT drawout breaker feeding a 1200A ATS which feeds a 200a dist panel? If not , why? THanks
Nope
What is A 16000AT drawout breaker?
1200 ATS make sense if it is a 1200 amp service?
zog
Senior Member
- Location
- Charlotte, NC
Nope
What is A 16000AT drawout breaker?
AT is often used to designate a trip setting, CT tap, or rating plug size on a breaker. AF is used for the frame size. So a 1600AT could be a 1600AF, 2000AF, 3000AF, 3200AF, etc....
rcwilson
Senior Member
- Location
- Redmond, WA
1600AF (1600 amp frame) circuit breaker feeding a 1200A ATS that supplies a 200A panel.
Many reasons for a design like this:
Typo on the panel, should be a 1200A Panel.
When equipment was ordered, critical loads were about 1000A, then they dropped to only 160A.
Difference in cost between a 1200AF & 1600AF is negligble. Using 1600AF kept spare parts down.
1600AF breaker is set for 1200A trip. (1600AF/1200AT)
1200A ATS is needed because a 200A doesn't have the required fault wihtstand rating.
Owner had a 1200A ATS on hand from the last job.
Designer/specifier had a bad day.
Many reasons for a design like this:
Typo on the panel, should be a 1200A Panel.
When equipment was ordered, critical loads were about 1000A, then they dropped to only 160A.
Difference in cost between a 1200AF & 1600AF is negligble. Using 1600AF kept spare parts down.
1600AF breaker is set for 1200A trip. (1600AF/1200AT)
1200A ATS is needed because a 200A doesn't have the required fault wihtstand rating.
Owner had a 1200A ATS on hand from the last job.
Designer/specifier had a bad day.
skeshesh
Senior Member
- Location
- Los Angeles, Ca
So is everyone assuming 16000 is a typo or am I missing something here?
rcwilson
Senior Member
- Location
- Redmond, WA
I've never seen a 16,000 A draw out. 5,000A is the largest I recall, maybe someone makes a fan-cooled 6,000A.
16,000 Amps would be about 5,760 MVA at 208V, 13.3 MVA at 480V. That's a lot of power. With typical transformer impedances of 5-7% that would be about 180 KA IC. I have installed generator breakers with ratings like that but they are not drawout.
My guess is that it is a 1600 Amp Frame we are discussing.
16,000 Amps would be about 5,760 MVA at 208V, 13.3 MVA at 480V. That's a lot of power. With typical transformer impedances of 5-7% that would be about 180 KA IC. I have installed generator breakers with ratings like that but they are not drawout.
My guess is that it is a 1600 Amp Frame we are discussing.
skeshesh
Senior Member
- Location
- Los Angeles, Ca
Sure. It's common though, to say something like "I think you meant 1600A" before responding, but I guess a 16000A trip feeding 1200A distribution is such an obvious fault that it doesnt need much of an explanation.
zog
Senior Member
- Location
- Charlotte, NC
Rare birds those 6000A beasts are but I have 6000A in stock made by ABB, GE, Westinghouse, and even Federal Pacific.
So do I , but if anyone ever finds a 16,0000A breaker let me know cause I want it!
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Alwayslearningelec
Senior Member
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- NJ
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- Estimator
Wow guys, I'm VERY sorry. it is a 1600A drawout breaker...ooops. Very sorry for the confusion.
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