Sub panel SEU al feeder sizing ?

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ritelec

ritelec

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Jersey
Looked at an existing sub panel
FP 12circ that is packed and feeds dryer range etc.
it also feeds a sub panel next to it that has another twelve circs in it.

The owner wants a price to replace what's there with one main lug panel.

The feeder to that FP comes from a CH 200amp main panel.

The feeder is SER 100amp #2 AL


There are circuits coming out of the 200 amp besides the sub panel feeder.

I'm thinking about replacing the feeder to larger conductors and putting in a larger (amperage ) panel

If I did just swap out the two older panels for one new 100 amp, would the existing 100amp SER be too small?
 
#2 AL SER is not a 100 amp feeder. Ignoring the recent 60C nonsense it should be protected by no larger than a 90 amp breaker.

These is no way anyone can tell you if the feeder is sized correctly without doing a load calc.
 
curt swartz said:
#2 AL SER is not a 100 amp feeder. Ignoring the recent 60C nonsense it should be protected by no larger than a 90 amp breaker.

These is no way anyone can tell you if the feeder is sized correctly without doing a load calc.
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If it was the 90a OCPD protecting the feeder would have tripped -- you could install a larger main lug panel 408.36 -- I am assuming the existing OCPD was correctly sized & done prior to 2008
 
mwm1752 said:
If it was the 90a OCPD protecting the feeder would have tripped -- you could install a larger main lug panel 408.36 -- I am assuming the existing OCPD was correctly sized & done prior to 2008
Click to expand...

Really??? Just because the feeder breaker hasn't tripped it automatically means the feeder is not overloaded? Have you made any proposals to have Article 220 completely eliminated? If so I guess the CMP hasn't agreed with you.

Even if installed prior to 2008 a 2/3 AL feeder not carrying the entire load of the dwelling could not be protected at 100 amps. This article has been rewritten every code cycle but still always ends up saying basically the same thing.
 
One of the most common violations I see when looking at feeders for sub panels, remote buildings etc. #2 Al on 100A breaker.

Surprisingly, I have brought this up several times in conversation with inspectors. Most all say they would approve the install.
 
nizak said:
One of the most common violations I see when looking at feeders for sub panels, remote buildings etc. #2 Al on 100A breaker.

Surprisingly, I have brought this up several times in conversation with inspectors. Most all say they would approve the install.
Click to expand...

Okay.

Thank you all

at the supply house the guy said he gives 2 al on SEU and 1 on SER. ( 90 and 100 75c)

Looking at the SE installation of it mentions 60c if in insulation.

I'm 99.999999 % sure the existing is #2.

He's never had a trip on the 100 (that I know of )

I told him I would increase the feeder two 150amp.

Not sure if I would have been ok just installing the panel on the existing feeder (inspection wise) but he's shopping numbers around so I figure I would do what I'm comfortable with rather than what his wallet is comfortable with.
The other guy might just install a panel, but that's on him.

Thanks again.
 
curt swartz said:
Really??? Just because the feeder breaker hasn't tripped it automatically means the feeder is not overloaded? Have you made any proposals to have Article 220 completely eliminated? If so I guess the CMP hasn't agreed with you.

Even if installed prior to 2008 a 2/3 AL feeder not carrying the entire load of the dwelling could not be protected at 100 amps. This article has been rewritten every code cycle but still always ends up saying basically the same thing.
Click to expand...

Time to chill out -- technically speaking a breaker that is over loaded is supposed to trip --- If your feeder can carry the load of the breaker then it is protected from overload -- I was applying the KISS rule for a question without specifics -- sure you can do a load calc but it is for the entire residence not for a subpanel -- so tell me -- a few lighting circuits(what sq ft do you put on the subpanel) -- is there a app circuit on it? -- what about heat/cooling -- the dryer 5500 & single range 8000 -- after the first 3000 watts then 35% -- even if not 13500w / 230 = 58 amps leaving plenty for lighting -- Or do you just amprobe the feeder with all loads working??????? How did you know I was trying to eliminate art 220 LMAO good 1 -- BTW I don't always agree with the CMP not sure all do.
 
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