Electrical Question

OK here is a chance for the electrical guru's to come out of the wood work and give their advise.

Was looking how a guy had a generator hooked into his electrical breaker box for a fishing camp.
He had a 220 breaker on what I would consider the output side of the box.
To this breaker he had the generator hooked to the box.
About 6 or 8000 watts.

I asked him about it.

Said when the electricity was on from the power company he removed this generator breaker and ground/neutral wire from the box.

When the electricity was off he turned off the main breaker disconnecting his box from the grid and installed this generator breaker back feeding the breaker box from a output breaker spot.

So the 2 hot wires are isolated from the grid because the main breaker is off but the neutral wire is still hooked to the grid because there was no disconnect for it.

Without considering the legal side of this how safe or unsafe is this????

(quoted from post at 18:03:53 07/21/19) OK here is a chance for the electrical guru's to come out of the wood work and give their advise.

Was looking how a guy had a generator hooked into his electrical breaker box for a fishing camp.
He had a 220 breaker on what I would consider the output side of the box.
To this breaker he had the generator hooked to the box.
About 6 or 8000 watts.

I asked him about it.

Said when the electricity was on from the power company he removed this generator breaker and ground/neutral wire from the box.

When the electricity was off he turned off the main breaker disconnecting his box from the grid and installed this generator breaker back feeding the breaker box from a output breaker spot.

So the 2 hot wires are isolated from the grid because the main breaker is off but the neutral wire is still hooked to the grid because there was no disconnect for it.

Without considering the legal side of this how safe or unsafe is this????

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here is no real interlock to prevent back feeding and injuring a lineman. Safety in that arrangement depends entirely upon the actions of a person with access to breaker box.

A few years ago, a lineman was killed because someone back feed .

Do it right or don't do it at all.

It's not safe, period.

Did you check if the fishing camp put any life jackets in their fishing boats, or was that another thing you really didn't want to know?

[b:654c4848f0]Safety in that arrangement depends entirely upon the actions of a person with access to breaker box[/b:654c4848f0]

I read that as it is a safe as a belt pully or a PTO on a tractor.
As long as you do not stick your hand in the pully or PTO it is safe.

It's not safe because it relies on a human to remember a specific sequence. And we all know we can't be trusted all the time, mistakes happen.

Depending on the box, some have kits available that allow that by using a mechanical interlock that allows only one of the two breakers to be ON at a given time. That can be done by making your own interlock, and would be safe but not listed or legal.

(quoted from post at 18:30:57 07/21/19) [b:3f9aa085a9]Safety in that arrangement depends entirely upon the actions of a person with access to breaker box[/b:3f9aa085a9]

I read that as it is a safe as a belt pully or a PTO on a tractor.
As long as you do not stick your hand in the pully or PTO it is safe.

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bout the way it is, except the danger/risk in the tractor situation is to the 'doer', whereas in the electrical case, the doer runs no risk, but puts others in danger. No risk except liability, that is.

I guess it?s his panel and his business so long as someone doesn?t get hurt or it doesn?t fall upon the eyes of an inspector. But no it?s not the fool proof safe way to hook it up because if you do it wrong or in the wrong order they?ll be problems.

A son in law comes to the camp. You are out finding a Morel mushroom to put in the breakfast eggs. Radio says power is back on. He, in his somewhat innocent best thinking, switches the main back on. And fries a lineman on the pole at the entrance to the cabin road. You see him fall, and know that it would have been a good idea to spend the few bucks on a real interlock. Jim

If both legs were balanced the neutral wouldn't matter. Probably rare in the real world. I actually had a Duke Power lineman tell me to hook up a generator backfeeding it year's ago.

No it isn't a good idea even though lots of people do it. I went a little far the other way and installed a generator inlet, panel box, wiring and outlets just for the generator.

Should have a transfer switch kit.

The connected neutral part of the question comes down to the generator. If the generator has a ?floating neutral? ie the neutral and ground are not connected at the generator, it is fine per NEC to have the neutrals connected at the transfer switch.

If the generator neutral is connected to ground at the generator, you are supposed to switch the neutral. My understanding is this is to prevent nuisance tripping of ground fault protection caused by having more than one path to ground.

Many of the code requirements, you can find a what if scenario that will cause a hazardous condition. It is a matter of which is the most likely what if.

Leaving the neutral connected is not a concern.

It's the human factor that is the potential for back feeding.

Problem is our short cuts outlive us.

Will the next person operating it know what to do?

(quoted from post at 18:46:14 07/21/19)
Depending on the box, some have kits available that allow that by using a mechanical interlock that allows only one of the two breakers to be ON at a given time.

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There is no excuse to not doing this the right way. The interlock kit for my Square D panel cast about $75. What is someone's life worth???????

Hey there John, see you in Florida again ??? as a retired power distribution design engineer that story MAKES ME SHIVVER Its NOT the safest or the correct or certainly NOT the NEC approved method.

Chief reason being instead of relying on Billy Bob or Bubba to be sure and remove or shut off that Genset backfeed breaker if its on and the genny is running given the right (wrong) set of circumstances it can kill someone. Similar the genset can be fried !!!!!!!!

Whats safe is a safety lock out slide type mechanism or a proper transfer switch so its impossible to backfeed the main.

SURE it can still "work" the way he does it but its not safe (potential for human mistake) and its not code proper


NEXT TO THE CONNECTED NEUTRALS, here's the deal:

A) If you only switch the Hots, NOT the Neutral, the Genset and Utility Neutrals can be bonded BUT the genset needs to have a FLOATING BEUTRAL

B) If you switch the Hots and the Neutral the Genset needs a Bonded Neutral, configured as a Separate Derived Source" plus connection to a Grounding Electrode

Where life and fire safety are concerned consult current practicing (that's NOT me too long retired) professional engineers and electricians and the NEC and don't risk your life on lay opinions !!!!!!!!!!!!!!!!

John T Too darn long retired EE so no warranty, consult professionals

John T
Not going to make it to Florida this year.
Been out of work for 4 weeks with 3 fractured lumbar vertebrae.
At least 2 more weeks to go.
So there goes all my vacation time and savings for this year.

I owe Gary a free lunch from a friendly bet.
Hope he does not think I did not go to get out of buying lunch. LOL.

Without considering the legal side of this how safe or unsafe is this????

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If the breaker box is not locked, and the gen is feeding the panel, it's horribly unsafe. If the breaker box is locked it's still unsafe, but not as bad as with it unlocked.

Buy him a transfer switch.

RE your question . . "Without considering the legal side of this how safe or unsafe is this????"

It is absolutely safe, as you described it. That is assuming no mistakes are make, i.e. "human error" while firing up the generator, making sure the main breaker is off, etc.

I doubt you will find anything in writing that specifically states this is "illegal" either, although I know you did not ask about legality. I hear a lot of nonsense and whining about the egregious "backfeeding." The reality is - when done right with no human making errors - it works fine. Is it dangerous considering the lack of redundant safety protection? Heck yes. No question a hard-wired transferswitch eliminates a lot of possible human error. That said, do not make the error and the backfeeding is fine and can hurt nobody.

I still keep a double-ended 50 amp extension cord hanging in my shop. Why? Just in case of a long power outage, I have a hardwired backup
9000 watt generator to give me power (with a transfer switch). If that ever failed, it was the middle of winter and I had to have power? I would just plug in my double-end NEMA 6-50 50 amp cord. One end into a 50 amp welder socket in my barn. Turn off the main 200 amp breaker in the house. Then plug the other end into my PTO 15KW generato and let it power my house. I have done it a few times over the past 50 years and always worked fine. I will do it gain if ever needed - regardless of all the "gloom and doom." It beats having the house freeze up, or having no water. I do not need "Bubba" to help me do it either.

I don't believe it. A lineman was killed because someone was back-feeding? Where and when. What line was this lineman working on? Service to a house after the transformer? I'd like a source citation that points me to the specific story with the details of exactly what happened.

I am not claiming it has never happened. I AM claiming I have never yet come across any verified account of it though. I worked as a lineman in NJ. So did my dad. Lineman - at least for the company we worked for were required to treat all power lines as hot - all the time.

Besides - this cannot even try to happen if someone is backfeeding into their own house and the main breaker is OFF, as the original poster described.

July 13, 2005
South Carolina Lineman Killed by Generator Back Feed
Victim Helping Restore Power in Alabama

Sumter Electric Cooperative (SECO) officials report that a South Carolina lineman helping to restore power in Alabama after the damage caused by Hurricane Dennis was killed late Tuesday, reportedly by an improperly installed customer generator.

According to SECO Director of Public Affairs Barry Bowman, the lineman was helping to restore power lost during Hurricane Dennis to customers in Alabama. The report Bowman received indicated the lineman was working on a power line that was supposed to be dead. It was not.

Not as bad, he wasn?t killed but still severely shocked;
Polk County, Fl
Wednesday, September 2, 2009 10:12 AM EDT
http://www.polkcountydemocrat.com/articles/2009/09/02/news/local/doc4a9dade2d4283632518688.txt
A Bartow electric department employee escaped a brush with death Monday night when a downed line he was repairing became energized by a homeowner?s generator.

Eddie Watson, an apprentice lineman, was grasping a line while wearing leather gloves as he worked to repair a line that was brought down by a falling tree in Monday night?s fierce thunderstorm.

When a homeowner whose house was served by the line started up a generator, it sent a surge of power through the line, Interim Electric Dir. Eschol Radford said.

The electricity went through a transformer, stepping up the voltage from 110 volts generated by the generator to 7,200 volts, the transmission voltage. Usually, the transformer does just the opposite, stepping down voltage from 7,200 to 110 volts for service lines to homes.

?He was lucky,? Radford said of Watson.

?Fortunately, he had a young guy, Scott Harrison, a lineman helper, working with him. Scott knocked him off the line and probably saved his life.?

Watson was rushed by ambulance to Lakeland Regional Medical Center, then transferred to the Tampa General Hospital burn center ?to keep an eye on him overnight.

?Fortunately, he only had a couple of burns on his hands; he was really lucky,? Radford said.

Watson was sent home on Tuesday, ?and is doing really well.?

The accident happened at Harney Road and Holly Lane in Alturas at about 9:30 p.m. Monday.

Safety procedures call for linemen to work every line as if it were energized, which includes the wearing of heavy rubber gloves, Radford said.

?He took a shortcut and got caught; we?ve all done it. He wanted to get the power restored as fast as possible.?

Watson has been employed by the city for about 20 years, half that time with the electric department, Radford said.

Harrison has been with the city three or four years.

Homeowners who use a generator to restore household power during an outage should turn off the main breaker to their home to prevent this type of accident, Radford said.

�Tragically, the line this technician was working on was not dead,� said Bowman, �The line he was trying to repair had been re-energized by a customer who had improperly hooked up a generator and created a back feed of electricity from the generator into the supposedly dead line. The death of a lineman who was there to help the victims of Hurricane Dennis was the horrible result.�

Bowman noted that the lineman�s name was not immediately released, but he was from South Carolina and worked for Pike Electric, Inc. in North Carolina.

Alabama authorities are looking for the person responsible and indicate that charges are pending.

lots of answers and opinions, so no need to add more, but a different thought is that "IF" something ever happens in a bad way, a really sharp and money thinking lawyer could/can/will bring up the " due diligence" clause...
so since you know about it, you could find yourself guilty by association...
Had this happen when a contractor fell off a wharf, drowned, and we got sued[gov] because the on site inspector "did not" make him wear a floater vest....but it was required in his contract to have them .....

"I doubt you will find anything in writing that specifically states this is "illegal" either,"
National Electric Code Article 702.5 requires an interlocking means to prevent the inadvertent connection of utility and generator sources of supply, so that is where it is in writing. Most utilities require this as well. That said, it works as long as you are careful to turn always off the main and the building inspector doesn't pay you a visit. But if you are going to do it this way make sure you turn off that main. If you don't you will backfeed the utility line, creating a hazard for linemen sent to restore power and two, you don't know when the power will be turned back on, and if you are out of phase, and you will be, there will be lots of smoke and sparks and you will probably never use that generator again.

What is your point? Your Code citation is NOT law and has nothing to do with legality. I chose my words carefully. Why mess them up? NEC is a published set of "suggestions" and nothing more. NO legal force behind it. If a town, county, city, state, etc. adopts portions of it and puts it into their laws and regs , THEN what they did is law.

The Neutral should be grounded via ground rod at the box. This is required by power companies. With the main (input) breaker open, I see no danger to linemen via feedback. Automated systems for generators do essentially the same thing.

The utility will ground the line before working on it.

Good point RJ, a do it yourself backfeed jury rig where you manually have to turn the Main OFF and the backfeed breaker on WITH NO AUTOMATIC LOCKOUTS OR SAFETY FEATURES

IS NOTTTTTTTTT how any Utility or local authority or inspectors (IF duly authorized and have jurisdiction that is) nor any of the NEC Seminar teacher/experts teach,,,,,,,,,,, ITS JUST NOT THE PROPER AND SAFEST WAY TO DO IT but sure many lay homeowners use that method no problems AS LONG AS ITS DONE RIGHT

HOWEVER, Sure if the operator switches correctly ??????????? its safe and works fine, I say to each their own methods they get no argument from me go for it, I'm not in charge of their life safety lol...

NOTE this is NOT me speaking, its what I learned form other experts and NEC board members and my education and experience as a Power Distribution Design Engineer and from professional licensed inspectors for much of my lifes career.

Soooooooooo do as one pleases its safe IFFFFFFFFFFFFFF done correctly BUT its NOT what experts,,,,,,,,,, and the NEC,,,,,,,,,,,and Utility Companies,,,,,,,,, and competent professional electricians and electrical engineers would advise

Where life safety is concerned why take chances is my thinking

PS Im also an Attorney but not going to open any can of worms regarding legality

John T BSEE, JD Electrical Engineer and Attorney at Law

You state: " The Neutral should be grounded via ground rod at the box. This is required by power companies."

INDEED the NEC and Utility require earth grounding of the incoming Neutral. In the jurisdictions where I practiced power distribution it was typically done at EITHER the riser weatherhead,,,,,,,,,the meter base,,,,,,,the main distribution panel by bonding to ALL READILY AVAILABLE Grounding Electrodes

NOTE this is NOT the same as Neutral Ground Bonding

John T BSEE,JD

(quoted from post at 20:53:58 07/21/19) I don't believe it. A lineman was killed because someone was back-feeding? Where and when. What line was this lineman working on? Service to a house after the transformer? I'd like a source citation that points me to the specific story with the details of exactly what happened.

I am not claiming it has never happened. I AM claiming I have never yet come across any verified account of it though. I worked as a lineman in NJ. So did my dad. Lineman - at least for the company we worked for were required to treat all power lines as hot - all the time.

Besides - this cannot even try to happen if someone is backfeeding into their own house and the main breaker is OFF, as the original poster described.

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Power goes off. Family is home, husband goes out and turns off main breaker, turns on gen. Leaves for work, tells wife 'don't mess with the electrical until I get back'. Power is being worked on, wife sees the power truck go by(husband at work), wife wants to check if power is back. Goes to breaker box, flips main - BOOM! First thing is arcs n sparks, next thing is someone upstream got a hellofa jolt. Wife turns breaker back off, 'hmmmm - I guess that was a mistake'.

Seen it. Not my wife, but neighbors, west of Co Springs CO(we get a lot of electrical storms), 2013 in late May, or early June. I had to repair the control panel and wiring for the generator.

It is unsafe because of the human error. People get excited during a power failure, often weather or other serious stuff is going on, and they forget the steps they are supposed to do. When it?s not to code it?s designed with only one person knowing for sure what to do, when that person isn?t around or there are new owners the safety issue gets worse.

You are asking if it works or not don?t care if it is safe. That is really your question.

It creates the potential for a lot of stray voltage, but it works the way you describe as long as there is never any human error involved. If he is running a dairy he will have unhappy cows while that setup is running, they are very sensitive to this.

Grounding a gen set is kind of an art I think, with all the ground rods and different ground loads coming from different areas to those grounds. Kinda hard to get to zero volts sometimes.

Paul

Maybe I am reading it differently than others here.

My first thought when I read fishing camp and when the power was off got me thinking it was a seasonal use site that was only connected to the utility for a portion of the year.

Could be up there off season doing some repairs and needed generator power to run maybe a saw or lights.

If the power company has pulled the fuse to the transformer on the site then there is no tie to the grid for back feeding although the transformer could still be reverse energized.

Does not make the set up code compliant but it would seem the risks of it causing a problem are low.

Thanks guys.

Your concern for human error is the reason I did not want to get into the legal side of this.
Could also be the reason he does not have this breaker and wires permanently mounted into the box.

Determined

A fishing camp to us is a second house that is not the permanent resident of the owner.
The only time the electricity would be off is in a weather related storm.

(quoted from post at 09:48:29 07/22/19) The utility will ground the line before working on it.

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TomA . Are you saying a proper interlocked transfer switch is not required ?

Buddy needs to get off his wallet and install one of these MA-24 Generlink units . http://www.generlink.com/generlink.html

You are incorrect, the NEC, as well as many other model building codes are referenced in their entirety by state building codes, and because state building codes are law, and say construction must comply with the NEC, the NEC is in effect law, not a suggestion. A building inspector will not approve a generator connection without a proper interlock precisely because of the section I cited.

JDEM, I agree with your points and have done mostly the same in the past when I lived in the country. My thoughts are that it is safe (as other knowledgeable folks here have said) as long as those involved KNOW how to handle electricity. I'm another BSEE who wouldn't have ever tried a standby generator hookup if I didn't KNOW electricity. A bit of common sense is good too!

What the installer, or designer, or engineer knows is not relevant.

What IS relevant is what the guy/gal/kid standing in front of the breaker box KNOWS at the time the gen is running.

Lots of ways for it to go FUBAR when Goober starts flipping things on and off ad-hoc.

That's a case of the wife being short on common sense because husband said don't mess with electrical until I get home !!!

I bet that it would be close to impossible to back feed the power line. Probably several or even a hundred of houses hooked to that line demanding power. It would blow the generators breaker imeadeatly! And if the power was back on it could fry th generator if it wasn't in phase. If it happened to be in phase, it would just load the generator down to its max output, or if the rpms were lower than the power company, it would just speed up the generator.

(quoted from post at 12:51:39 07/23/19) I bet that it would be close to impossible to back feed the power line. Probably several or even a hundred of houses hooked to that line demanding power. It would blow the generators breaker imeadeatly! And if the power was back on it could fry th generator if it wasn't in phase. If it happened to be in phase, it would just load the generator down to its max output, or if the rpms were lower than the power company, it would just speed up the generator.

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Are you saying that a fail safe generator interlock is not required ?

I did not say that. There's always the
chance that there are only a few houses
that is on the same line as you are. In that case a generator could start a few refrigerators and pumps or other demands.