Wire Gauge does power "direction" matter?

[Spudland_Dave]

So stupid thought...might be a stupid post...and lets not get into the "Safety police thing"

But does FEEDING power via Generator make any difference at all vs using the power there? Or will my length make a difference?

On my back wall where I'll have a NEMA 14-50 recep right next to my garage door, which will be used when I want to weld outside...perfect place to hook up my generator too. SOOO if I use 8ga THHN, that goes into my panel 50' away...then that panel goes to the main which is 97' away... Any concerns?

Generator is a Kubota GL6500, 6500 watt, 30a...

 

[Maine]

A lot of factors here.

If you are proposing to backfeed a panel without a transfer switch that is against the code for safety reasons, however most will just make sure their main breaker is off.

#8 conductor at 150' is on the edge of not being sufficent for 30 amps, but it will work okay.

 

[Spudland_Dave]

#8 conductor at 150' is on the edge of not being sufficent for 30 amps, but it will work okay.

Technically the juice will be going thru, 40' of #8 THHN, then 20' of #4 THHN, then hop onto 90' of 2-2-2-4 to get to the main panel in the house.

 

[eljefino]

You could always "juice" the governor of your genset if voltage at the end outlet is a couple percent too low under load.

 

[Maine]

You will be fine Dave.

 

[rlitman]

Back to the question of the topic, no direction does not matter, because in an AC circuit, there isn't even such thing as direction. With the voltage alternating, electrons go back and forth, and have no way of sensing "direction".

So whatever losses you have in one direction, you will get in the other too.

 

[Spudland_Dave]

You could always "juice" the governor of your genset if voltage at the end outlet is a couple percent too low under load.

Problem here would be how would I even know if the fridge isnt getting what it needs?

Back to the question of the topic, no direction does not matter, because in an AC circuit, there isn't even such thing as direction. With the voltage alternating, electrons go back and forth, and have no way of sensing "direction".

So whatever losses you have in one direction, you will get in the other too.

Gotcha...so its 50A both ways no worries...Didnt even think about it that way.

 

[theoldwizard1]

Technically the juice will be going thru, 40' of #8 THHN, then 20' of #4 THHN, then hop onto 90' of 2-2-2-4 to get to the main panel in the house.

Where it will go out the main up the power line and possibly kill a utility worker.

 

[Highbeam]

I did this the legal way with an interlock but all it is is a 30 amp circuit ran to the outside wall and rather than an outlet plug there is an inlet plug. I used about 80' of 10/3 wire. 8/3 is plenty.

Your genset has a 4 wire twistlock plug, does your 8 gauge inlet wire have 4 wires?

 

[madosta]

Where it will go out the main up the power line and possibly kill a utility worker.

A loose tree limb (widow maker) could also fall on the line worker while he's working on the down line and kill him.

The game of what-if's is stupid to play. Leaving your main on when backfeeding is a stupid, but when this happens, the OP will be the one dealing with the problems e.g. lawsuits.

Yes it's a valid concern, but it's also only a possibility that the OP or the future resident would be stupid enough to leave the main closed.

 

[Spudland_Dave]

A loose tree limb (widow maker) could also fall on the line worker while he's working on the down line and kill him.

The game of what-if's is stupid to play. Leaving your main on when backfeeding is a stupid, but when this happens, the OP will be the one dealing with the problems e.g. lawsuits.

Yes it's a valid concern, but it's also only a possibility that the OP or the future resident would be stupid enough to leave the main closed.

Ultimately my wife and everybody around knows...this is for me and me alone to hook up. But thats besides the point...

I had another post typed up, basically said...I'm not opposed to interlocks, I'm really not...I had reasons not to hook one up on my original "outlet/inlet", but now I really cant...
A) If I interlock my Garage Feed...no power in the garage when street power is on....
B) Interlock the garage panel...OK that works, but then I could care less about my GDO's having power...Furnace/Fridge/Freezer in the house is what counts.

 

[Alchymist]

Backfeeding issues have been discussed to death on this and other sites. Not going to comment on the safety issues, but I will say this:

IF the POCO sees it, and there is no approved transfer switch, (say during an outage you are the only one with lights) they will, in many areas, cut the service drop to the building, and it won't get reconnected until a proper switch is installed. And it will be a very low priority to reconnect. Just sayin....

 

[madosta]

Backfeeding issues have been discussed to death on this and other sites. Not going to comment on the safety issues, but I will say this:

IF the POCO sees it, and there is no approved transfer switch, (say during an outage you are the only one with lights) they will, in many areas, cut the service drop to the building, and it won't get reconnected until a proper switch is installed. And it will be a very low priority to reconnect. Just sayin....

The "hearsay" of this has also been discussed. I'm just full of it today. Happy Friday.

This forum is great. It has sparked my interest into what other solutions are available for something like this when an interlock wouldn't work and a transfer switch would be way out of the way... maybe a remote disconnect. Maybe we could invent a remote transfer switch and sell it!

 

[Spudland_Dave]

IF the POCO sees it, and there is no approved transfer switch, (say during an outage you are the only one with lights) they will, in many areas, cut the service drop to the building, and it won't get reconnected until a proper switch is installed. And it will be a very low priority to reconnect. Just sayin....

How can they see that and gather that info? I dont have any "Generator" feeds wired anywhere...I have no clue what your talking about.
During an emergency like an ice storm or whatever...when the Generator would be needed & used...they got better things to do then come look in everybody's house. Heck EVERY Damn time some disaster happens, you'll hear about some dumb a$$ who was running the generator in the basement and died of carbon monoxide....or lit the garage on fire because the generator was running in there. Actually having it wired 1/2 correctly is more then what 90% of the generator users do....

My brother in law back feeds his thru his Range outlet...POCO gonna hit his house and shut him down because he has a range outlet? May as well run around and un-hook everyone's power now...

I knew this thread would decend into a Safety Police thread....

But my question remains...what is the safest/approved way in a situation where you got a Sub Panel in a garage or somewhere else that you can hook up to.

 

[Alchymist]

How can they see that and gather that info? I dont have any "Generator" feeds wired anywhere...I have no clue what your talking about.
During an emergency like an ice storm or whatever...when the Generator would be needed & used...they got better things to do then come look in everybody's house. Heck EVERY Damn time some disaster happens, you'll hear about some dumb a$$ who was running the generator in the basement and died of carbon monoxide....or lit the garage on fire because the generator was running in there. Actually having it wired 1/2 correctly is more then what 90% of the generator users do....

My brother in law back feeds his thru his Range outlet...POCO gonna hit his house and shut him down because he has a range outlet? May as well run around and un-hook everyone's power now...

I knew this thread would decend into a Safety Police thread....

But my question remains...what is the safest/approved way in a situation where you got a Sub Panel in a garage or somewhere else that you can hook up to.

Duh - whole area is without power and you have lights on in the house----??

I realize it's a waste of time talking to people who are determined to do their own thing......

But here's some info direct from the horses mouth:

http://www.cpi.coop/safety/outage-preparation/generator-safety-and-installation-information/

http://nj.gov/governor/news/news/552012/approved/20121026c.html

http://www.cmpco.com/UsageAndSafety/electricalsafety/GeneratorSafety/backfeed.html

https://www.pplelectric.com/my-account/outage-center/use-of-backup-generators.aspx

https://www.firstenergycorp.com/help/outages/what_to_do_if_youlosepower/using_backup_generators.html

 

[Highbeam]

Ho
But my question remains...what is the safest/approved way in a situation where you got a Sub Panel in a garage or somewhere else that you can hook up to.

You put the interlock on your main panel and backfeed the entire system from your garage through the subpanel. Cheap, easy, legal, and allows you to backfeed the whole system legally. You may not care if your GDO is powered up but it won't hurt anything and won't draw any power unless you want to use the opener.

There is no need for this to be a safety thread. Interlocks make it legal but all the interlock does is assure that the main utility feed from the streeet is off. It WORKS the same with or without the interlock "kit" so electrical issues are the same whether you choose to install the interlock or not.

I did install the interlock and had it inspected and approved by the state for personal reasons. The power company has no way of knowing this and they have not cut my service drop.

 

[Alchymist]

You put the interlock on your main panel and backfeed the entire system from your garage through the subpanel. Cheap, easy, legal, and allows you to backfeed the whole system legally. You may not care if your GDO is powered up but it won't hurt anything and won't draw any power unless you want to use the opener.

There is no need for this to be a safety thread. Interlocks make it legal but all the interlock does is assure that the main utility feed from the streeet is off. It WORKS the same with or without the interlock "kit" so electrical issues are the same whether you choose to install the interlock or not.

I did install the interlock and had it inspected and approved by the state for personal reasons. The power company has no way of knowing this and they have not cut my service drop.

It appears reading comprehension is not abundant today - must be the weather.

!) The drop is only cut, (if it's the power company's policy), WHEN there is a power outage, the linemen see your lights on and discover a generator backfeeding without the proper disconnect.

2) More importantly, you cannot have an interlock in the main panel and backfeed from a sub panel. The interlock and feed must be in the same panel.

I guess the question is, why do I bother?

 

[rlitman]

2) More importantly, you cannot have an interlock in the main panel and backfeed from a sub panel. The interlock and feed must be in the same panel.

That is what I'm trying to figure out. You can do it actually, but you would need a "Kirk Captive Key Interlock" or equivalent. That is not something you can just get in a kit for your panel, and you would need approved engineering drawings, etc.

 

[larry_g]

I guess the question is, why do I bother?

You bother because it is the correct thing to do and I'll bet each time someone new discovers that there are laws and switches to consider when using a generator. Just like every PVC airline thread I'd bet someone new learns it is a bad thing.

lg
no neat sig line

 

[Alchymist]

That is what I'm trying to figure out. You can do it actually, but you would need a "Kirk Captive Key Interlock" or equivalent. That is not something you can just get in a kit for your panel, and you would need approved engineering drawings, etc.

Sounds more expensive than a simple transfer switch. If one really wanted to feed from the garage, run a separate line from the garage to the transfer switch or interlocked panel at the house, with the male plug at the garage.

 

[FunkyfullWidth]

An outlet in the garage is just that... An outlet in the garage. I feel that as long as you know to flip the main on and off when either welding or running a generator you're good. There's plenty of houses out there that run generators like that with no interlock or disconnect other than the main. If in an emergency or power outtage, I don't really see the power companys knockin on doors to make sure generators are hooked up correctly.

 

[rlitman]

Hey, it's the internet. You didn't expect a better answer, did you?
I was just suggesting that it can actually be done. I'm pretty sure the extreme cost and complexity is the reason nobody ever does it this way, although I do have some key interlocks at work for places where nothing else will suffice.

Your answer was certainly the best "real world" answer. No arguing that.

 

[Larwyn]

If the power goes out here, and it's dark outside, I mostly use battery operated camping lanterns for light. If the power is out long enough for me to worry about the fridge/freezer, I will fire up my 4200 watt Generac and run an extension cord to the appliance of choice. If the generator is running I may operate a lamp or two to help conserve lantern batteries for a while. I do not back feed my house wiring but I do have a generator and lights during an outage. Thankfully the power company here has the common sense to know that house lights are not a positive indication that I am back feeding their line/substation/power plant. They have yet to cut the feed to my house, or even knock on my door, just because my living room is well lit during an outage.

I have a feeling that if I were trying to back feed the distribution line here with my little generator, it would bog down and die very quickly due to all of the load that is still connected to that line. A lineman would have to act very quickly to get zapped if someone tries to back feed the line. If I could power my street off my little generac I would be selling power, not buying it........

 

[Highbeam]

Correct, this notion that the power company will somehow know about your home's internal wiring is ridiculous as is the pathetic idea that they would cut your service drop. Weak scare tactics at best.

You can backfeed your main panel from a subpanel. It will work. If you don't think so then you had better be able to explain yourself better than just saying so.

 

[Alchymist]

Correct, this notion that the power company will somehow know about your home's internal wiring is ridiculous as is the pathetic idea that they would cut your service drop. Weak scare tactics at best.

You can backfeed your main panel from a subpanel. It will work. If you don't think so then you had better be able to explain yourself better than just saying so.

Reading comprehension is still lacking. Ill post this as a last comment, then I'm through.

Backfeeding through a sub - panel will "work". It is not only against code, but dangerous.

Anyone want further clarification just call your local power company and ask. Post the results here, not just your "opinions.

 

[Highbeam]

Unfortunately, you did agree that it will work alchymist. No reason why it would or why it would not be totally safe to backfeed through a subpanel. So your contribution is nill?

 

[Alchymist]

Unfortunately, you did agree that it will work alchymist. No reason why it would or why it would not be totally safe to backfeed through a subpanel. So your contribution is nill?

You may take my contribution for whatever value you place on it. I care not how you wire your house. Your call. (Read the whole post).

 

[Highbeam]

You may take my contribution for whatever value you place on it. I care not how you wire your house. Your call. (Read the whole post).

Worthless. Anybody actually know a reason why backfeeding through a subpanel would be a problem? We actually want to know if there is a reason.

 

[Alchymist]

Worthless. Anybody actually know a reason why backfeeding through a subpanel would be a problem? We actually want to know if there is a reason.

You got what you paid for.

 

[FunkyfullWidth]

Alchymist, your right... Your word is god, everyone should abide by what you say to be true.... We are all but illiterate trash. Comprehension skills are terrible at best...

 

[Alchymist]

Alchymist, your right... Your word is god, everyone should abide by what you say to be true.... We are all but illiterate trash. Comprehension skills are terrible at best...

Glad you see it my way!

Actually, I don't care who believes, who does what, etc. To each his own. The applicable NEC is out there; I don't care if anyone chooses to follow it. If one goes back and reads carefully one will see that assumptions were made, points were missed, etc. Anyone reading the posts can draw their own conclusions as to what's right or wrong.

I don't think I attacked anyone personally........If someone construed it that way, my apologies.

 

[KPSquared]

He never asked if it was right or wrong. . .he asked if it could be done. It can. I backfeed, through a sub. I have to run up to the power pole and kill the main breaker. Then keep my eye on the closest neighbor and see when there lights come on. . .

 

[Alchymist]

He never asked if it was right or wrong. . .he asked if it could be done. It can. I backfeed, through a sub. I have to run up to the power pole and kill the main breaker. Then keep my eye on the closest neighbor and see when there lights come on. . .

Actually, the OP asked "SOOO if I use 8ga THHN, that goes into my panel 50' away...then that panel goes to the main which is 97' away... Any concerns?". (Color added).

 

[Spudland_Dave]

Actually, the OP asked "SOOO if I use 8ga THHN, that goes into my panel 50' away...then that panel goes to the main which is 97' away... Any concerns?". (Color added).

For the record...I take no personal offense...
Secondly, Alchymist is right I asked more along the lines of wire gauges..kinda feels funny to be "feeding" smaller to larger so to speak...that and even though I've researched it here and on the rest of the web, and I see 8ga THHN is fine for 50A, I've never done it that way so I am just a little apprehensive about it. The various members here have put me at ease about going that way, and then I was thinking "wait a minute...does hooking up a 50A generator there change anything?" Yes, I know my generator is only 30A, but my brother has a nice Miller Trailblazer which is 50A. Better to wire & plan for 50A and hook up 30A then vice versa.

I've got another 14-50 recep hooked up with 6ga "Romex" at my "closer" sub panel already...I'd probably put the generator there so I can see it from the warmth of the house...but at the same time, I'd like to be able to hook it up anywhere if it came to it.

Oh an Alchymist...You should take this time to brush up on your reading comprenhension skills as well, in my OP I clearly stated "and lets not get into the "Safety police thing"...sorry I had to say it

 

[Aceman]

It amazes me people spend as much time as they do researching and installing circuits with a ton of receps scattered all over for their garages, simply for convenience.

But when it comes to safety and something that's very much required, it isn't worth the time and expense.

 

[eljefino]

Worthless. Anybody actually know a reason why backfeeding through a subpanel would be a problem? We actually want to know if there is a reason.

If you have an interlock between your main breaker and your garage subpanel breaker, in your main box, you can only have one on at a time. So the garage lights will never work off grid power.

If you have a backfeed breaker on your main panel, and one of those hokey slide this, slide that kits, the backfeed breaker and the wire coming out of it is going to be dead when your main is on.

If you put the interlock on your sub panel, the power that goes to your house won't stop there, and will keep going on up out the meter and off to the neighborhood.

off topic, the PSA/AD the local power company runs shows linemen using "sniffers" to see if down wires are live. Presumably they could sniff your service feed and passively aggressively chop it. I haven't heard of it happening, but they probably justified and allow for it in their operations manuals and to the PUC.

 

[KPSquared]

It amazes me people spend as much time as they do researching and installing circuits with a ton of receps scattered all over for their garages, simply for convenience.

But when it comes to safety and something that's very much required, it isn't worth the time and expense.

All those outlets are for my convenience. . .I don't know how back feeding through my sub panel affects my safety. . . Seems to work just fine. . .I feel safe and so does my beer.

 

[Alchymist]

Oh an Alchymist...You should take this time to brush up on your reading comprenhension skills as well, in my OP I clearly stated "and lets not get into the "Safety police thing"...sorry I had to say it

Not to be a smart a$$, but posts #2, 8, & 10 brought it up, before I posted anything.

 

[Larwyn]

This is the first time I can recall that I actually wish that I had a few minutes back on the job before I retired. I would truly like to test just how big a generator it would take to handle the inrush current required to energize the typical pole mounted transformer secondary winding. I actually have my doubts that the typical homeowner has a backup generator that could handle the load. Especially when you consider the inrush of all the additional transformers on the line, not to mention the loads that the other homes still have connected to the line. The extreme overload would simply prevent the generator from running.

I know my little Generac 4200 watt generator, when running my smaller 5th wheel trailer, would stall if the air conditioner kicked in while the microwave was running. The motor would stall before the breaker considered tripping.

So it seems to me that if you hear a generator running, chances are it is NOT connected to the grid (unless it is the very large generator that belongs to the power company).

There is the chance that, after failed attempts to start up a generator, the owner would turn off the output breaker of the genset, crank up the generator without load, then close in the breaker. In that case there would be a real danger to anyone on the line for a VERY short period of time. So it is dangerous not to disconnect from the grid but a running generator is a pretty reliable indication that this has been done.

 

[Highbeam]

If you have an interlock between your main breaker and your garage subpanel breaker, in your main box, you can only have one on at a time. So the garage lights will never work off grid power.

If you have a backfeed breaker on your main panel, and one of those hokey slide this, slide that kits, the backfeed breaker and the wire coming out of it is going to be dead when your main is on.

If you put the interlock on your sub panel, the power that goes to your house won't stop there, and will keep going on up out the meter and off to the neighborhood.

off topic, the PSA/AD the local power company runs shows linemen using "sniffers" to see if down wires are live. Presumably they could sniff your service feed and passively aggressively chop it. I haven't heard of it happening, but they probably justified and allow for it in their operations manuals and to the PUC.

THanks Elf, I almost understand. I have an interlock (a slidy thing) that shuts off the main power from the grid to my main panel. Interlock engaged = no grid tie but all breakers in the main and sub are connected still. The shop subpanel is fed from a breaker in the main panel. If I backfed an outlet in the shop, through the subpanel, it seems to me that both the main and supanels would be enrgized since they are all still connected and the only thing disconnected in the grid feed.

I think it will work electrically as KPSquared states. What do you think is happening that would stop electricity from feeding both panels from my subpanel?

The lineman argument is irrelevant since the main breaker is shut off.