8-2 uf nmcb 100'
- Thread starter yotarover
- Start date
Charles (in GA)
Well-known member
I had to read this about three times, yes, electric cable, 8-2 w/grd UF (if the welder doesn't need the neutral internally for any 120v circuits, would be fine on a 30 amp breaker/30 amp receptacle circuit. This is single phase, there is no two phase commonly available in the US (though it does exist in a couple of rare instances).
Are you running this underground? If no, you really do not need the UF cable and a jacketed romex type cable is much cheaper.
Charles
Are you running this underground? If no, you really do not need the UF cable and a jacketed romex type cable is much cheaper.
Charles
prob not underground if it's checks out i will run it from the porch where my sub pan is out to the building about 10ft off the ground maybe a lil higher
NEC 250.122(B) will not allow one to use a larger NM or UF cable for the use invisioned in the OP.
Here is a copy & paste from the 2008 NEC.
(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately according
to the circular mil area of the ungrounded conductors.
6 & 8 AWG NM & UF cable has a 10 AWG equipment grounding conductor & because of the above code section disallows the use of either size or type for 30A, because one cannot put a larger EGC in the cable assembly.
Here is a copy & paste from the 2008 NEC.
(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately according
to the circular mil area of the ungrounded conductors.
6 & 8 AWG NM & UF cable has a 10 AWG equipment grounding conductor & because of the above code section disallows the use of either size or type for 30A, because one cannot put a larger EGC in the cable assembly.
sberry
Banned
I am not sure I understand this response to this question or issue.
sberry
Banned
You trying to say he cant limit this to 30A?
i read the book im seeing the same thing. http://www.globalindustrial.com/site/images/universal/Southwire/uf-b.pdf
shows 6&8 with a 10g ground it also shows that i had a max of 40amps
im still confused though alotta ppl are running 30amps on 6awg even 8 just for welding
even though i see that a 50 will work better for a 240v stick welder. but that means i have to get 6awg to use a 50amp breaker
shows 6&8 with a 10g ground it also shows that i had a max of 40amps
im still confused though alotta ppl are running 30amps on 6awg even 8 just for welding
even though i see that a 50 will work better for a 240v stick welder. but that means i have to get 6awg to use a 50amp breaker
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sberry
Banned
I know you are confused and between this and the other forums it goes from bad to worse. There is no danger running the 50A stick machine on this wire with a 50, its 2 sizes larger than it needs to be to be legal, even though the minimum is not very good. You would melt the welder in to a little puddle before over heating the wire.
Having said that I think the inspector is a great idea, or find a legitimate electrician to help with this.
None of the proposals meet any sembleance of a legal installation, a panel needs a 3 wire + ground and it would need to be limited to 40A which would make welding with a Tbolt marginal. There are some cases where this wire could be used to power specific appliances with a limited duty cycle, some cases 8 may be ran to 100A but not this cable and not with a 10 ground with that high of over current protection. 6 wire and 60A max with a 10 ground. Bigger wire and or larger breaker needs an 8.
Having said that I think the inspector is a great idea, or find a legitimate electrician to help with this.
None of the proposals meet any sembleance of a legal installation, a panel needs a 3 wire + ground and it would need to be limited to 40A which would make welding with a Tbolt marginal. There are some cases where this wire could be used to power specific appliances with a limited duty cycle, some cases 8 may be ran to 100A but not this cable and not with a 10 ground with that high of over current protection. 6 wire and 60A max with a 10 ground. Bigger wire and or larger breaker needs an 8.
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The problem is when you increase the ungrounded (hot) conductors you must also increase the grounding conductor, when the grounding cond. is part of a cable assembly such as NM, UF, MC, one cannot comply w/ the requirement, if the run is in a conduit there is no problem to upsize it or if metallic skip the grounding conductor alltogether...
sberry
Banned
The wire in the cable is already an assembly, comes with the correct ground wire, he didn't change anything, he didn't increase the conductors at all, he is just using a lower breaker than the max allows.
If you increase the wire size on the ungrounded conductor you MUST increase the grounding conductor proportionally there is no exception for anything in the code section, and he would be using a larger size conductor then required.
NEC section 250.122(B) 2008 edition.
(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately according
to the circular mil area of the ungrounded conductors.
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measurement as of earlier
from main panel to sub in building = 97'
from sub in house to building= round 75'
Route- safest, easiest, least expensive
welder-some type of SMAW lin,miller,hobart, 200v-240v
i can still exchange the 8-2uf nmcb i have and get 8-3
or 6-3 if it doesn't go over my budget which is x= welder,chop saw,electrodes, 240v wiring
6awg has a amp rating of 55amps
with that said can i just run 6-3UF *either buried or strung through air* with a 50amp breaker/outlet, outdoor gang box, with clr cover?
what you don't know is
building was previously wired by step dad (deceased) with 12-2 and 2 20amp breaker in sub panel. wiring was cut some years ago and has to be reran back into the house to have power again. perfect for turning back on the lights and installs outlets to run power tools,grinder,etc and maybe my compressor if i go with a 30amp breaker.
from main panel to sub in building = 97'
from sub in house to building= round 75'
Route- safest, easiest, least expensive
welder-some type of SMAW lin,miller,hobart, 200v-240v
i can still exchange the 8-2uf nmcb i have and get 8-3
or 6-3 if it doesn't go over my budget which is x= welder,chop saw,electrodes, 240v wiring
6awg has a amp rating of 55amps
with that said can i just run 6-3UF *either buried or strung through air* with a 50amp breaker/outlet, outdoor gang box, with clr cover?
what you don't know is
building was previously wired by step dad (deceased) with 12-2 and 2 20amp breaker in sub panel. wiring was cut some years ago and has to be reran back into the house to have power again. perfect for turning back on the lights and installs outlets to run power tools,grinder,etc and maybe my compressor if i go with a 30amp breaker.
Have you ever had an inspector catch this? It would never happen in Maine with a piece of UF
^ i've seen a lot of things where i live even though i live in town out county or out of the city limits they have **** rigged up to work and no problems.
since i own my home im thinking that if i run it safely and use the right size breaker one that wont go spark and bun down anything i'll be fine
like say 8-3 or 6-3 50a breaker main panel,straight down to the ground and trenched up to the building sub panel with another 50a breaker to the nearest outlet within 3ft with the same wire
at the local community college the construction class builds all the habitat houses around here and various other business buildups (cheaper for the owner and hands on for the students) it's taught by a well known guy. well certified (more than i can count) im going to run it by him when i get to school Monday
sberry
Banned
First, there is no argument that you probably know more about electric than I ever will, so we can get that out of the way right now, but, that does not apply to this cable. By this implication this cable would be suitable if he put a 40A breaker on it vs a 30 is that correct? That section is for individual wires where the installer has increased wire size for V drop, say he went from a 6 to a 4 he would need to use an 8 vs a 10, could still be fed by a 50A breaker.
He hasn't changed the relationship uf the conductor size to the ground wire
he hasn't changed this relationship, he just didn't put as large as breaker on as allowed, no rule says you have to use as large a breaker as you can.
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hidollartoys
Well-known member
# 10 AWG ground is good up to 60 amps. 250.122(B) only applies if you increase the size of conductors to compensate for voltage drop, increased ampacity, etc. This really falls under250.122(F)(1)....Grounding conductor based on OCPD.
Go back and read the code section & tell me where it says that, if the ungrounded conductor(s) are increased the grounding conductor must be increased, it says nothing about voltage drop or any other thing, 250.122(B) supersedes everything else.
Norcal is right on this one, even it defies logic. Perhaps someday this part of the code will be refined.
It sounds like the OP wants to power a detached garage/shed with both 120 volt and 240 volt loads. If so he needs a four wire feed and ground rods at the existing breaker panel in the structure.
A picture of the existing panel would help.
It sounds like the OP wants to power a detached garage/shed with both 120 volt and 240 volt loads. If so he needs a four wire feed and ground rods at the existing breaker panel in the structure.
A picture of the existing panel would help.
hopefully pics will be on the way no i just want 1-240v line for welding as i just bought a new 240v ever last pro arc 200amp stick welder
here is the idea i don't like the plan of running more wire through my house ( in the event something fucks up all the wire is outside and connected to the main service panel * why because it's just safer in my situation*
been told and seen it stated most stick welders need 50amps
so 6-3 << (i switched from the 8-2 )with 2 50amp breakers and i don't have to wire it to the sub in my building im going to make a brace to hold a pullout that will have it's own sub panel attached to it *weather rated outdoor one* that will have a outlet running from it for 50amp service and then go weld
what is the problem? if you can't run uf that why then why the hell is it made the way it is?
sberry
Banned
I dont get where he is increasing, it says proportionately, he didnt increase the proportions. ALL he is doing is using a smaller breaker, so let me get this right, all he would have to do then is increase the breaker to 40A and all would be well? If he runs any less than a 60A breaker on a number 6 wire he has to increase the groiund wire?
read that^ i never said i wanted to restore the 120v power i said that it would have the be reran back into the house again (it's already up to code) my mom had a walk way put in leading to the driveway which they cut the line it lies under the concrete and is unhooked at the panel and the cut part is unhooked at the building no problem with fixing that but i want 240v service from a totaly different line (a dedicated line just for the welder from outside
i'll think of you as my electrical lawyer
i'll help you get the facts of what i want and plan to do
run 6-2 or 6-3 from main with 50 or 60amp breaker to building underground
(mobile homes have a post with the meter and panel etc i will make one of these) << it will be outdoor rated a pullout to kill power when im not using the outlet/ prob wont need a sub panel but might for another breaker and then the outlet for the weder (im using a stick for this setup)
#6 UF is only rated for 55 amps, so a 50 amp breaker would be fine.
The reason I mentioned the 110 volt circuits is you are only allowed one feed to detached building, so restoring the old damagred feed is not an option once the new wire is installed.
The reason I mentioned the 110 volt circuits is you are only allowed one feed to detached building, so restoring the old damagred feed is not an option once the new wire is installed.
sberry
Banned
But, if fed with a 40A breaker the ground wire would have to be increased?
i know i'll prob look into getting some 240v lighting or something in that nature as in welding at night with no light will kinda **** till i get the arc struck
so aside from the legal beagle **** i can prob run the 6/2 from the main to the building and call it good or will i need 6/3 ?
sberry
Banned
You need 6/3. UF this allows for both voltages. 240V lighting is not really an option in this type of building and you want to be able to run other 120V tools, grinders, even the 140 welder.
Aceman
Well-known member
I always thought this rule was kinda funny. I know a lot of electricians that run 100 amp feeders using #2 Cu, including the members on here, that don't upsize their grounds from #8 to #6 when doing so.
So I'm asking everyone, including electricians, who's been failed for that violation?
I haven't yet. But I do try to run #3 more often now, because I don't want to find out the hard way.
Fauj
Well-known member
Not to hijack the OP's thread, but could you point me (us) to a handy web reference that specifies current capacity of various conductors. Working on my own garage plans. Thanks.
I have been failed for not upsizing to #6 grounding cunductor with #2 on a 100 amp circuit.
My local amendments prohibit using non-threaded conduit and fittings for ground, so I always pull a ground wire.
You can use an online calculator, here's a link to some various ones:
http://www.electrician2.com/calculators/elcal.html
Fauj
Well-known member
sberry
Banned
So, what size would the ground need to be with a 30A circuit?
sberry
Banned
I understand about this upsize requirement Ace but what about when its included in the cable?
The conduit would be the grounding conductor, as soon as a EGC is pulled the rule in 250.122(B) kicks in again.
ok im lost on this ruling thing if it already has a 10awg ground with the wiring and even if it's put into conduit why does the rule stand when nothing is going bigger? all i want to do is run the 6-3 uf on a 50amp breaker to the building wire in a disconnect panel and breaker it again.
then maybe use the 8-2 that i already have or maybe the 12-2 that is already in the building ( no sense in wasting it) and use it to power 120v devices air compressor,grinder,lights drill press
yes i know it was said it will work on a 50-60amp breaker
how can the rule keep poping up though if nothing is changed is what im asking
then maybe use the 8-2 that i already have or maybe the 12-2 that is already in the building ( no sense in wasting it) and use it to power 120v devices air compressor,grinder,lights drill press
yes i know it was said it will work on a 50-60amp breaker
how can the rule keep poping up though if nothing is changed is what im asking
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If one uses 8/2 NM or UF on a 40A breaker or 6/2 NM or UF on a 50A breaker, all is well, as soon as you decrease the rating of the fuse / circuit breaker on those cables then the rule kicks in, because the ungrounded conductor was "increased in size". Just one of those rules that can be baffling at times.