20 amp 240v GFCI outlet? - Page 2 - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > Electric Brewing > 20 amp 240v GFCI outlet?

Reply
 
Thread Tools
Old 11-28-2012, 09:47 PM   #11
DustBow
 
DustBow's Avatar
Recipes 
 
May 2010
Cincy, OH
Posts: 634
Liked 21 Times on 19 Posts


I think he has 10 gauge wire from the 30amp breaker to to his 20 amp fuses, then 12 gauge wire from there on out.
__________________
"Brewers make wort, yeast make beer."

"Brewing beer is neither complicated nor expensive. It's the responsibility of the brewer to make it as complicated and expensive as their spouse & budget will allow."

 
Reply With Quote
Old 11-28-2012, 09:55 PM   #12
jeffmeh
HBT_SUPPORTER.png
 
jeffmeh's Avatar
Recipes 
 
Feb 2009
Posts: 2,146
Liked 210 Times on 180 Posts


Quote:
Originally Posted by DustBow View Post
I think he has 10 gauge wire from the 30amp breaker to to his 20 amp fuses, then 12 gauge wire from there on out.
Ah, so 30amp breaker with 10 gauge house wiring to the wall receptacle. Then 10 gauge from the wall receptacle into the 20 amp fuses in the control panel. Then 12 gauge from there. That is perfectly reasonable.

 
Reply With Quote
Old 11-28-2012, 10:09 PM   #13
yjfun
Recipes 
 
Jun 2010
Arlington, Washington
Posts: 225
Liked 2 Times on 2 Posts


Thank you DustBow.

 
Reply With Quote
Old 11-29-2012, 12:36 AM   #14
ryane
Recipes 
 
Nov 2008
Washington
Posts: 841
Liked 7 Times on 7 Posts


Quote:
Originally Posted by jeffmeh View Post
Isn't the issue that you have 12 gauge house wiring with a 30a breaker that is oversized for and won't protect the wiring, as your permanent installation? I would think that would not conform to code. Again, I am not an electrician.
He's got it here,

Regardless of your fusing, #12 wire cannot handle 30A per code, if you had a short in the wire prior to your fuse, the circuit would not blow until 30A, which the #12 wire is not rated for

When working residential I come across this issue quite a bit with #14 wire and 20A breakers. Its not to code and if it were wired this way and a fire happened due to the wiring its unlikely insurance would cover the damages.

 
Reply With Quote
Old 11-29-2012, 12:55 AM   #15
jeffmeh
HBT_SUPPORTER.png
 
jeffmeh's Avatar
Recipes 
 
Feb 2009
Posts: 2,146
Liked 210 Times on 180 Posts


Quote:
Originally Posted by ryane View Post
He's got it here,

Regardless of your fusing, #12 wire cannot handle 30A per code, if you had a short in the wire prior to your fuse, the circuit would not blow until 30A, which the #12 wire is not rated for

When working residential I come across this issue quite a bit with #14 wire and 20A breakers. Its not to code and if it were wired this way and a fire happened due to the wiring its unlikely insurance would cover the damages.
If he had a short prior to the fuse, would not the fuse blow first to protect the 12 gauge wire in the control panel, then the 30A breaker throw to protect the 10 gauge wire running from the breaker to the fuse? There are plenty of appliances and electronics that use fuses and smaller wire than the household wire matched to the breaker, yes? This is the same thing as far as I understand it.

 
Reply With Quote
Old 11-29-2012, 12:56 AM   #16
yjfun
Recipes 
 
Jun 2010
Arlington, Washington
Posts: 225
Liked 2 Times on 2 Posts


ryane,

You need to take a look in your code book. It's not legal to land a number 12 wire under a 30 amp breaker in most situations but number 12 THHN is physically rated to handle a 30 amp load so there is no worry that the wire will fail before the breaker trips.

 
Reply With Quote
Old 11-29-2012, 01:57 AM   #17
ryane
Recipes 
 
Nov 2008
Washington
Posts: 841
Liked 7 Times on 7 Posts


Quote:
Originally Posted by yjfun View Post
ryane,

You need to take a look in your code book. It's not legal to land a number 12 wire under a 30 amp breaker in most situations but number 12 THHN is physically rated to handle a 30 amp load so there is no worry that the wire will fail before the breaker trips.
I didnt see that you had #10 to the fuses and then #12 out, still your getting into murky territory and personally I would have run #10 the full length, its not much more $ anyway

also by NEC (in my earlier post) while #12 THHN is rated to 30A up to 90C, 240.4(D) supercedes anything else for small conductors eg #10,12,14, and states that the max load on a #12 is 20A, #10 is 30A, and #14 is 15A

Regardless of what your doing, which seems to be working for you, I put up my cautionary post for others reading the thread and personally I would recommend against others replicating it at home

 
Reply With Quote
Old 11-29-2012, 05:22 PM   #18
yjfun
Recipes 
 
Jun 2010
Arlington, Washington
Posts: 225
Liked 2 Times on 2 Posts


The way I look at it is

1: That I can't impose greater than a 19 amp load on the wire

2: The wire can actually handle 30 amps

3: Everything is protected by a 20 amp fuse

4: The fuse would blow in the case of a short circuit well before the wire would melt.

5: Article 240 doesn't supersede everything. I have put lots of 30 amp breakers on number 12 wire in a perfectly legal installation in accordance with Article 400 and 240.21.

 
Reply With Quote
Old 11-30-2012, 04:11 AM   #19
whoaru99
Recipes 
 
Oct 2012
Posts: 1,759
Liked 140 Times on 117 Posts


Quote:
Originally Posted by ryane View Post
I didnt see that you had #10 to the fuses and then #12 out, still your getting into murky territory and personally I would have run #10 the full length, its not much more $ anyway

I"m not sure why this is murky, it's the basic premise for structure wiring.

Large breaker protects panel and overall load, medium breakers may protect the wires to a sub panel, then within the sub panel smaller breakers protect the branch circuits.

For example, perhaps you have a 200A main, then within that main panel a 50A breaker over 6ga wire feeds a sub panel , then within the sub panel 20A breakers protect 12ga branch circuits.
__________________
Drinking: Store Bought
Kegged: Cream Ale

 
Reply With Quote
Old 11-30-2012, 04:17 AM   #20
whoaru99
Recipes 
 
Oct 2012
Posts: 1,759
Liked 140 Times on 117 Posts


Quote:
Originally Posted by yjfun View Post
The way I look at it is

1: That I can't impose greater than a 19 amp load on the wire

2: The wire can actually handle 30 amps

3: Everything is protected by a 20 amp fuse

4: The fuse would blow in the case of a short circuit well before the wire would melt.

5: Article 240 doesn't supersede everything. I have put lots of 30 amp breakers on number 12 wire in a perfectly legal installation in accordance with Article 400 and 240.21.
Ahhh...but the point isn't what applies in some cases, it's what applies to the specifics of the circuit at hand. Let's not obfuscate...
__________________
Drinking: Store Bought
Kegged: Cream Ale

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
jump a 240v outlet? BucksPA Electric Brewing 2 11-11-2011 06:29 PM
240V 50A Outlet Installed SeattleMatt Electric Brewing 7 09-19-2011 04:26 AM
Can I use a regular GFCI wall outlet, (like in your bathroom)? shortyjacobs Electric Brewing 7 06-23-2011 02:18 PM
240v Outlet Placement jhollist Electric Brewing 2 06-21-2011 04:38 PM
placement of GFCI outlet kappclark Electric Brewing 7 03-05-2011 06:13 PM


Forum Jump