For all you "20 ampers"

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For all you "20 ampers"

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iwire said:
OK, I will be waiting. :grin:



I have plenty of 8, 10, 12 and 14 NM here in storage at the house so cost is not an issue, I still use 14 AWG for a lot of the work. It makes me happy.

Now at work, thats different, mostly 10 AWG for 20 amp circuits more then 100'. To me the load characteristics of commercial circuits are entirely different then dwelling unit circuits. :smile:
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Most architects by me spec 10 wire on runs over 75 ft
 
iwire said:
Well obviously the architects in your area are much better then the engineers in my area. :wink:
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Architects are in a whole other world of thinking. I know of an office building that does not seem to have a square room in it....tables with angles so they wiil join the walls...triangular rooms...it's like being in the fun house at Six Flags and it is supposed to be a professional office building!
 
mivey said:
Architects are in a whole other world of thinking. I know of an office building that does not seem to have a square room in it....tables with angles so they wiil join the walls...triangular rooms...it's like being in the fun house at Six Flags and it is supposed to be a professional office building!
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Was this the place?

plumbandsquare.jpg




Roger
 
growler said:
To say that #12 is not better than #14 is much like saying that EMT is not better than NM. I have never seen a rat bite through EMT and chew off the insulation on the conductors inside the conduit. Not even those high tech. flying squirrels.
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Why is EMT better in home wiring and if it is why arent you using it? I don't think we have a huge rat problem in this country but if you have one where you are you might try some traps. some areas in the country use EMT because the city burned to the ground once and they aren't sure but they think maybe a cow started it. so they have gone overboard to see it doesn't happen again.
 
growler said:
...I have seen voltage drops as high as 12-14% when #14 was used. People just don't think about how long many of the runs really are by the time they get to that last device. It really suprised me.

I'm willing to bet that most of those that use the argument of an unknown load have never measured nor calculated voltage drop for that last receptacle.

I think your 12 amps is a good size load to use for an estimate and that's what I use to check for voltage drop. ( I cheat and use the Sure Test to measure voltage drop)
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Wow commercially we use 180VA as a projected load of general use receptacles; maybe you are using larger items in your home bedrooms then commercial sites? :grin:

Distances can go much farther than you may think when a circuit is actually installed. I've just unrolled some old plans of a 4,100 sq ft house that has a livable space footprint of 80'L x 40'W. It's a full custom home and there will be a sub panel 1/3rd of the distance from edge in a utility room. I can measure lineal footage (as it would get wired) from this sub panel to the farthest point, and accommodate for rise and fall, through devices and I have 170 feet to the last farthest outlet.
VD = 2.9% with 3.3A (396VA) load @ 170' from source, then
The next circuit closer has a distance of 150' to the last outlet
VD = 2.9% with 3.8A (456VA) load @ 150' from source, then
VD = 3.0% with 4.1A (492VA) load @ 140' from source, then
VD = 3.0% with 4.4A (528VA) load @ 130' from source, then
VD = 2.9% with 4.7A (564VA) load @ 120' from source, then
VD = 2.9% with 5.6A (672VA) load @ 100' from source, then
VD = 2.9% with 7.0A (840VA) load @ 80' from source
Voltage drop certainly does take place in all cases but there is a difference between voltage drop and damaging voltage drop. It occurs more with the increase of current/distance/the downsizing of conductors. 3% (3.6V) it's the most acceptable because it is referred to in the NEC.
If there are concerns with load there are safe way's to work with this like, sub panel (usually needed for circuit space anyway), smaller multi-receptacle circuit just for vacuum cleaner (halls, first outlet each bedroom)
Try a real test by plugging in a 12A vacuum in a 15A branch circuit turn it on and check voltage, try this in multiple locations, you can go father distances than you may think walking through a house. Make your results your policy it's you prerogative, but DON'T slander your pears to the public by scaring them to believe any less than #12 is dangerous!
Article 220 & example D2 reveal a way to safely calculate a residence:
Sub total other load
1st 10 KVA @ 100%
Remainder @ 40%
Total other load
Loads @ 100%
Largest motor @ 25%
Total VA
Unlike non-dwelling that must calculate continuous loads (lighting) @ 100% separate from non-continuous like receptacles (1st 10 KVA @ 100% & remainder @ 50%)
Article 220 & example D2 exemplifies the reality that only some items will be loaded some times by the fact the first 10 KVA is 100% and the remainder at only 40%. That is what a general lighting branch circuit is going through.

I'm one of those that use the argument of an unknown load :roll:
 
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Rmc

Rmc

bikeindy said:
Why is EMT better in home wiring and if it is why arent you using it? I don't think we have a huge rat problem in this country but if you have one where you are you might try some traps. some areas in the country use EMT because the city burned to the ground once and they aren't sure but they think maybe a cow started it. so they have gone overboard to see it doesn't happen again.
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That being said .wonder why they just did not use rigid!
 
bikeindy said:
Why is EMT better in home wiring and if it is why arent you using it? I don't think we have a huge rat problem in this country but if you have one where you are you might try some traps. some areas in the country use EMT because the city burned to the ground once and they aren't sure but they think maybe a cow started it. so they have gone overboard to see it doesn't happen again.
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Allways trying to blamethings on the COW huh??
 
bikeindy said:
Why is EMT better in home wiring and if it is why arent you using it? I don't think we have a huge rat problem in this country but if you have one where you are you might try some traps. some areas in the country use EMT because the city burned to the ground once and they aren't sure but they think maybe a cow started it. so they have gone overboard to see it doesn't happen again.
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Come now indy, if EMT were not a superior product and considered much safer it would not be allowed in structures that require a fire rating.

They only reason that NM is allowed is because it's cheap to work with.
If you ever go into an attic where the squirrels have been at the wiring you will see what I'm talking about. Until you see it the first time it's hard to believe how much damage rodents can do. And the good thing is that home insurance does not cover rodent damage.

The standards for residential are just not very high. I could cut my way into many homes with a pocket knife, they are cracker boxes.

The only reason I don't use EMT for residential is because no one is willing to pay the extra cost. I really do think that people who built these super expensive homes are crazy to use Romex.
 
growler said:
Come now indy, if EMT were not a superior product and considered much safer it would not be allowed in structures that require a fire rating.

They only reason that NM is allowed is because it's cheap to work with.
If you ever go into an attic where the squirrels have been at the wiring you will see what I'm talking about. Until you see it the first time it's hard to believe how much damage rodents can do. And the good thing is that home insurance does not cover rodent damage.

The standards for residential are just not very high. I could cut my way into many homes with a pocket knife, they are cracker boxes.

The only reason I don't use EMT for residential is because no one is willing to pay the extra cost. I really do think that people who built these super expensive homes are crazy to use Romex.
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i had a rodent chew through an rg6 coming from the satellite dish up an exterior wall at my house once. would've been a nightmare if it had chewed through any romex.
 
brantmacga said:
i had a rodent chew through an rg6 coming from the satellite dish up an exterior wall at my house once. would've been a nightmare if it had chewed through any romex.
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Found a dead (long dead) rat on NM once - much earlier than the digital camera - would have made a got shot.... It chewed into it - apprently died right there and over time the conductor corroded and caused an open - which caused me to go look for it - if I remember correctly it was #12. If it were 14 the rat would have lived IMO.....:roll:
 
growler said:
I really do think that people who built these super expensive homes are crazy to use Romex.
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Unless those super expensive homes are built out of non-combustible construction using anything more then NM would be a waste of money.
 
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