I've got the POWER!

[nexgen91]

I think this is the first thread I have ever posted here, but I am super excited today, and had to share my excitment, and this video that feels so appropriate:

I finally have a 100Amp sub panel in my garage, no more tools bogging down, no more lights flickering, and not more breakers flipping. Wooohooo!!! I can now get my new compressor, hook up my dust collector, and use my welder when I need to (outside the garage door, because you know dust and welding dont mix). Cost me around $740 for the run (all the way from the other end of my house) up through my laundry room and out into the garage, and a GFCI outlet to start. Here is a pic of the install: https://imgur.com/a/iS5PA

 

[malibu101]

Hi "neighbor".

Enjoy having the power!

 

[wyliesdiesels]

OK comeon now. This is the garage journal. No untouched detail goes missing without questioning...

U need to give us all the juicy details if youre gonna be doing that kinda of bragging.


brand of panel?
feeder size and type?
number of circuits?
etc etc.....

And congrats BTW

 

[pattenp]

Did you do the install? I see one code violation already. That frying pan is too close to the panel.

 

[LX-Markham]

congrats!

100A panel was the first thing I did to my garage.
Took the 100A panel from the basement, installed a 200A service, then used the old panel as a sub-panel in the garage.

 

[nexgen91]

Sorry for the late reply. I didnt do the install, i didnt want to have to feed the feeder all the way from the main panel and through the tiny space it needed to go through. Its a Square D panel, only the one 30 amp circuit installed for now but i got room for plenty more (i think its a 20 circuit panel, damn bad memory). Tge feeder is aluminum rated at 100amp. Ill get to moving that frying pan pronto it needs to go back in the kitchen, but i need to restore it first (the list ia long, and time is short). Ill try to get more pics and better details/plans up tomorrow.

 

[nexgen91]

Hi "neighbor".

Enjoy having the power!

Hi there your right up the road

 

[pattenp]

That conduit looks too small for #1 aluminum which is needed for 100A. Is it 1.5".

 

[nexgen91]

That conduit looks too small for #1 aluminum which is needed for 100A. Is it 1.5".

No I dont think it is, looking at the jacket it reads "3 CDR AWG 2 0 HWG 4 COMPACT... AlumaFlex (TM) AA8176 TYPE SE CABLE STYLE SER Type XHHW-2 CDRS 600 VOLTS MADE IN USA" The electrician says it is up to code and guaranteed it to pass the inspection, so once I get the rest of the wiring done and have the inspection completed I will know for sure (I am not a residential electrician by any means, aircraft are my thing). Anyone know if they goofed, its about a 75 foot run?

Doing a calculation (assuming this is #2 Alu) on the southbend site give me:
Results
1 conductors per phase utilizing a #2 Aluminum conductor will limit the voltage drop to 2.01% or less when supplying 100.0 amps for 75 feet on a 220 volt system.
For Engineering Information Only:
110.0 Amps Rated ampacity of selected conductor
0.3042 Ohms Resistance (Ohms per 1000 feet)
0.045 Ohms Reactance (Ohms per 1000 feet)
6.6000000000000005 volts maximum allowable voltage drop at 3%
4.401. Actual voltage drop loss at 2.01% for the circuit
0.9 Power Factor

 

[pattenp]

NEC only allows 90A on #2 Al as a branch feeder.

 

[wyliesdiesels]

No I dont think it is, looking at the jacket it reads "3 CDR AWG 2 0 HWG 4 COMPACT... AlumaFlex (TM) AA8176 TYPE SE CABLE STYLE SER Type XHHW-2 CDRS 600 VOLTS MADE IN USA" The electrician says it is up to code and guaranteed it to pass the inspection, so once I get the rest of the wiring done and have the inspection completed I will know for sure (I am not a residential electrician by any means, aircraft are my thing). Anyone know if they goofed, its about a 75 foot run?

Doing a calculation (assuming this is #2 Alu) on the southbend site give me:
Results
1 conductors per phase utilizing a #2 Aluminum conductor will limit the voltage drop to 2.01% or less when supplying 100.0 amps for 75 feet on a 220 volt system.
For Engineering Information Only:
110.0 Amps Rated ampacity of selected conductor
0.3042 Ohms Resistance (Ohms per 1000 feet)
0.045 Ohms Reactance (Ohms per 1000 feet)
6.6000000000000005 volts maximum allowable voltage drop at 3%
4.401. Actual voltage drop loss at 2.01% for the circuit
0.9 Power Factor

That is 2-2-2-4 AL SER.

#2 AL is limited to 90a in this application as Pattenp said.

What site is this that says #2 AL is good for 110a? Even in the 90* c column, #2 AL is rated at 100a. The NEC allows #2 AL to be breakered at 100a when it is supplying the entire load of a dwelling.

 

[Dr Stan]

Good for you, nothing like having power in the shop. I went a different route with two meters, 200amp to the shop & 100 to the house. Costs me about $10/month more, but the convenience factor is well worth it.

During the shop construction I ran a 10ga extension cord from the house, but as soon as it was dried in I had the electrical inspected. BTW melted one of the ends of a 10ga extension cord.

Had an ancient 100 amp breaker box in the house and the breakers were running me $25 each. After the 2nd one went it was out with the old and in with the new.

 

[nexgen91]

Now I got a delimma, should I just say screw it and throw a 90 amp breaker in the main (I don't really need the full 100 amps) or should I ask the electrician to come back and change it? If I ask them to come back before inspection, how would I go about telling them it is wrong? Thank you

 

[acer66]

Now I got a delimma, should I just say screw it and throw a 90 amp breaker in the main (I don't really need the full 100 amps) or should I ask the electrician to come back and change it? If I ask them to come back before inspection, how would I go about telling them it is wrong? Thank you

90amp breaker in the main.

 

[Muzzy]

Call the electrician and ask. He may have information we don't.

 

[rburke65]

Did you contract for a 100 amp. feed to your garage or a 90 amp. feed to the garage?

 

[nexgen91]

Did you contract for a 100 amp. feed to your garage or a 90 amp. feed to the garage?

100 amp

 

[wyliesdiesels]

Now I got a delimma, should I just say screw it and throw a 90 amp breaker in the main (I don't really need the full 100 amps) or should I ask the electrician to come back and change it? If I ask them to come back before inspection, how would I go about telling them it is wrong? Thank you

call him and ask him to replace the breaker.

The inspector may be old school and think 100a on #2 al is ok but its not.

Call the electrician and ask. He may have information we don't.

Its the other way around. The electrician is behind on code and doesnt know the correct info. This happens a lot with #2 al...

 

[pattenp]

If it's getting inspected and passes with a 100A feeding breaker then so be it. Personally I would not lose sleep over the #2 Al being on a 100A breaker. Do you plan on loading the panel at 100% all the time? I don't think so.

That's the bad part of coming here to show off you electrical, someone will rain on your parade.

 

[nexgen91]

If it's getting inspected and passes with a 100A feeding breaker then so be it. Personally I would not lose sleep over the #2 Al being on a 100A breaker. Do you plan on loading the panel at 100% all the time? I don't think so.

That's the bad part of coming here to show off you electrical, someone will rain on your parade.

I dont plan on loading it to 100% for sure. I am ok with it like it is (I am probly going to push 60-70 amps max), I am just worried about if it gets inspected when/if I ever sell the house.....

 

[ddawg16]

I think a Tim Allen "O O O" impression would fit right now....

 

[Sovereign-1]

No I dont think it is, looking at the jacket it reads "3 CDR AWG 2 0 HWG 4 COMPACT... AlumaFlex (TM) AA8176 TYPE SE CABLE STYLE SER Type XHHW-2 CDRS 600 VOLTS MADE IN USA"

Doing a calculation (assuming this is #2 Alu) on the southbend site give me:
Results
1 conductors per phase utilizing a #2 Aluminum conductor will limit the voltage drop to 2.01% or less when supplying 100.0 amps for 75 feet on a 220 volt system.

You and everyone is thinking its a 2-2-2-4 AL SER wire but you have 2 0... did you mean 2/0. If this is 2 ought cable then all is fine. Maybe take a picture of the jacket? I am just an amateur but I just want to be sure we all know what the wire truly is.

 

[wyliesdiesels]

You and everyone is thinking its a 2-2-2-4 AL SER wire but you have 2 0... did you mean 2/0. If this is 2 ought cable then all is fine. Maybe take a picture of the jacket? I am just an amateur but I just want to be sure we all know what the wire truly is.

2/0 would have a larger EGC- a #1. his says #4

 

[Sovereign-1]

2/0 would have a larger EGC- a #1. his says #4

Ah, I see now. Thanks.

 

[pattenp]

2/0 would have a larger EGC- a #1. his says #4

I was thinking #2 because of the #4. I think the info got copied wrong from the jacket. It should read something like "3 CDR AWG 2 1 CDR AWG 4", but who knows. A picture of the jacket info would be good.

 

[wyliesdiesels]

I was thinking #2 because of the #4. I think the info got copied wrong from the jacket. It should read something like "3 CDR AWG 2 1 CDR AWG 4", but who knows. A picture of the jacket info would be good.

Yeah the 0 before the CDR confuses things.

 

[nexgen91]

I was thinking #2 because of the #4. I think the info got copied wrong from the jacket. It should read something like "3 CDR AWG 2 1 CDR AWG 4", but who knows. A picture of the jacket info would be good.

I am not at home right now but I got these the other day.
http://imgur.com/a/VqrXk

 

[nexgen91]

That is 2-2-2-4 AL SER.

#2 AL is limited to 90a in this application as Pattenp said.

What site is this that says #2 AL is good for 110a? Even in the 90* c column, #2 AL is rated at 100a. The NEC allows #2 AL to be breakered at 100a when it is supplying the entire load of a dwelling.

Southwire voltage drop calculator: http://www.southwire.com/support/voltage-drop-calculator.htm

 

[pattenp]

I am not at home right now but I got these the other day.
http://imgur.com/a/VqrXk

That picture is "3 CDR AWG 2 1 CDR AWG 4" as I suspected. So 90A is what's allowed by the NEC.

To decipher, three conductors of #2 and one conductor of #4.



*

 

[nexgen91]

That picture is "3 CDR AWG 2 1 CDR AWG 4" as I suspected. So 90A is what's allowed by the NEC.

To decipher, three conductors of #2 and one conductor of #4.



*

Thank you, so I guess I need to contact the electrician.... should I just tell him "yeah some guys on a forum said its not within code..." and either "I need the breaker changed to a 90 Amp" (and a partial refund since it was contracted for 100 Amp) or "I need it rewired with the correct gauge feeder" ????

 

[wyliesdiesels]

Southwire voltage drop calculator: http://www.southwire.com/support/voltage-drop-calculator.htm

U mustve either read it wrong or put the wrong info in.

When i input 240v, 3%, 100a, and 75' i get 1/0 AL.

Regardless of what southwire says, NEC max ampacity of #2 al is 100a under 90*c column which is for derating only and feeders serving the entire load of a dwelling.

 

[wyliesdiesels]

Thank you, so I guess I need to contact the electrician.... should I just tell him "yeah some guys on a forum said its not within code..." and either "I need the breaker changed to a 90 Amp" (and a partial refund since it was contracted for 100 Amp) or "I need it rewired with the correct gauge feeder" ????

Tell him he needs to check the ampacity table 310.15(b)(16)

He cant argue with the table.

As i said above 90* c column is for derating only and cant be used for breaker sizing.

 

[nexgen91]

Tell him he needs to check the ampacity table 310.15(b)(16)

He cant argue with the table.

As i said above 90* c column is for derating only and cant be used for breaker sizing.

Copy that thank you. How does this sound? "Got an issue with the install, according to the NEC ampacity table 310.15(b)(16) max ampacity of #2 al is 100a under the 90*c column which is for derating only and feeders serving the entire load of a dwelling, so it is below spec for the sub panel install. Please advise on how we should move forward." Should I give options ie: swap breaker for 90amp and refund or replace cabling, or should I just leave it open ended (Im horrible with things like this)?

 

[pattenp]

You just need to do what makes you satisfied. Technically it doesn't meet NEC requirement and if your jurisdiction enforces the NEC then it should be corrected. As far as telling him where you got the info just say from the NEC Article 310. In more recent NEC additions 2011, 2014 the table is 310.15(B)(16), and using the 75 deg.C column, #2 Al is 90A.

 

[pattenp]

I'd start out with telling him I contracted for a 100A and the wire doesn't meet code for 100A and then don't say anything else. Don't give any options and see what he says and go from there.

 

[nexgen91]

I'd start out with telling him I contracted for a 100A and the wire doesn't meet code for 100A and then don't say anything else. Don't give any options and see what he says and go from there.

ok i sent him an email, we'll see what happens

 

[nexgen91]

Heard back from electrician after sending this message: "Got an issue with the sub panel install, according to the NEC ampacity table 310.15(b)(16) max ampacity of #2 al is 100a under the 90*c column which is for derating only and feeders serving the entire load of a dwelling. t was I contracted for a 100A but the wire doesn't meet code for feeding a subpanel at 100A ."

Here is the reply i got from the electrician.... "Table 310.15(b)(16) does say that I agree. We work with #2 ser on 100amp breakers regularly. The inspector(s) we deal with read the code differently and hold that it is misinterpreted and shouldnt be applied in this case. Between the UL listing and the #2 Ser being a concentric neutral it is compliant. I'd be happy to put this through a 3rd party inspector and adhere to the result but I don't agree that #2 ser isn't compliant on 100amp circuit breaker feeding a subpanel within 65ft. We guarantee our work to be code compliant. Let me know how you would like to proceed. This is a widely disputed code application and this isn't our first time dealing with it. Interpretation and application of code can be difficult."

 

[Muzzy]

Right or wrong, sounds like you have a stand up electrician.
As I said before, they have information we may not.

NEC is clear, but application may vary by jurisdiction. Call borough hall and ask their opinion.

 

[bry@n]

Congrats. I put a 50'amp in my garage and I'm a little sorry I didn't go 100 from the start.

 

[AntonLargiader]

You've already said it doesn't bother you, and your experienced electrician and experienced AHJ apparently have thought about this issue before and consider this setup OK. 90A is a super typical subpanel arrangement and if it ever becomes an issue at sale you can a) point to the approved inspection, and b) throw a 90A breaker in there.

I think the electrician acted in good faith. He quoted the job based on how it's done locally. Provided you pass inspection, I'd just call it done and start using that new capacity!