Generator backfeeding into utility lines

[JB4310]

It's certainly expensive for a bracket, but much cheaper than a 200A DPDT switch/breaker which can run $1000 or more. So I guess in comparison it's a bargain.

Yup and they are as big as a dorm fridge. HF has a cheaper version but I did not like it, looks to be an import. (DUH HF)

Just the switch alone is expensive, it's no small job to install. makes that interlock all the better. Not sure what size the max you could switch with an interlock ??? I know 50 amp no problem, can you go to 100 amp??

The $175 was just for the bracket. You may find a better price.

Back feeding is sending power out of your house to the power lines.

You can power up your house legally. Just do it the right way.

Well I guess that's what it means to me, but I've seen any type of powering the panel referred to as back feeding???

It is probably also UL listed, so your insurance company cannot use it as a reason to deny coverage if something happens.


Aaron Z

They claim they are, and will pass code. Probably why Bob went with the manufactures model instead of his home brew. for that little (or greater) extra piece of mind, it's worth it.

JB.

 

[JB4310]

At the risk of taking this off on a tangent....

I've never read anything in my homeowner's policy that says coverage only applies if things are UL listed. Has anyone seen such language in an insurance policy?

Maybe not but if you had a major claim stemming from an electric problem and they come in and see a makeshift device on your electric panel. (Referring to a home made interlock).
Might very easily create problems. Till you could prove it did not cause the loss, if you could.

JB.

 

[aczlan]

They claim they are, and will pass code. Probably why Bob went with the manufactures model instead of his home brew. for that little (or greater) extra piece of mind, it's worth it.

Exactly. Not hard to make one yourself, but if something electrical goes wrong, your insurance company would probably try to use your homemade interlock device as a reason to deny coverage. Harder for them to do that with a UL listed one that is installed per the manufacturers instructions.


Aaron Z

 

[tmajor]

See my post, which addresses the same issue. Some of the "manufacture's interlocks" can be purchased for a little as $55. Search your Load Center to see what is available.

 

[BobRip]

It is probably also UL listed, so your insurance company cannot use it as a reason to deny coverage if something happens.
EDIT: ('it' being a UL listed interlock vs a home made one)

Aaron Z

That is the reason I changed mine. That is swapped out homemade to UL listed.

 

[hosspuller]

Another thought ... When the power is restored to a line that is connected to a generator ... which genset will win the tug-o-war of line frequency?

Your 10 kva or so genset or the utility's 1.5 megawatt unit

 

[Dan in CT]

I work for the local utility, some years ago down in the "affluent" corner of the state we had such an incident. A large house (15-20,000 sq ft) was the only customer on a side tap whose fuse had blown during a storm. The line was patrolled, no damage spotted, so the fuse was put back in, not knowing that his generator was back-feeding the tap. Owner came flying down the driveway, claiming we blew up his generator. Yes, we did blow it up, and no, we weren't responsible, since he had an improper connection (no transfer switch).

 

[Mace Canute]

I work for the local utility, some years ago down in the "affluent" corner of the state we had such an incident. A large house (15-20,000 sq ft) was the only customer on a side tap whose fuse had blown during a storm. The line was patrolled, no damage spotted, so the fuse was put back in, not knowing that his generator was back-feeding the tap. Owner came flying down the driveway, claiming we blew up his generator. Yes, we did blow it up, and no, we weren't responsible, since he had an improper connection (no transfer switch).

HA! HA! HA! HA! Hearing THAT makes me smile! Serves him right! I hope it was an expensive generator too!

*Retired Journeyman Lineman here, eh!*

 

[Qapla]

Our local utility (we have a co-op) has a policy "If it isn't grounded ... it isn't dead!" Therefore, when they work on any downed line, they ground ALL legs.

a few years back when they were working on a downed line on our road, when the lineman was getting out his grounding wires, he was explaining to us why the repair would take a little longer. They had to take the time to make sure it was dead before they could start. This meant grounding all legs. In the dark, they do not rush this step.

When he put one of the grounding leads on some sparks were emitted from the clamp. He said something about there being an "illegal generator" connected to the line. Then after he finished tightening the clamps, he commented on the "surprise" the homeowner would have when they found their generator was fried.

Since they have introduced the "If it isn't grounded ... it isn't dead!" policy, they have not had any linemen get hurt. No telling how many generators they have fried.

 

[slowzuki]

I think its safe to say the general public never assumes a downed line is safe. I'd say almost only retired pole cats and copper thieves might assume such a thing! Most of the public can't tell the difference between phone wires and the power lines, and most of them wouldn't touch a piece of power line that wasn't even connected on the ends.

The general public may assume a downed line is safe because they can see a blown fuse.

 

[kco]

I think its safe to say the general public never assumes a downed line is safe. I'd say almost only retired pole cats and copper thieves might assume such a thing! Most of the public can't tell the difference between phone wires and the power lines, and most of them wouldn't touch a piece of power line that wasn't even connected on the ends.

Really? You're that sure?

I put in the statement because posters were discussing dangers to linemen who almost always would anticipate a backfeed danger even with an open fuse. I'm not so sure all the general public would do so.

 

[sailorman]

I think its safe to say the general public never assumes a downed line is safe. I'd say almost only retired pole cats and copper thieves might assume such a thing! Most of the public can't tell the difference between phone wires and the power lines, and most of them wouldn't touch a piece of power line that wasn't even connected on the ends.

Might be time to define what you call the general public. I watched many of the general public wade through waist high water in N.O . ( I 'm local ) after Katrina assuming downed power lines in the water were safe .

 

[Tractor Seabee]

This seems to be taking on a life of its own. Electrical safety is not to be taken lightly, that is why there are codes, they are for public safety which may well be you. To the poster with out a main breaker: If you want to feed your whole panel you will need a service rated transfer switch, they are twice the cost of a standard double pole-double throw knife blade switch. Then unless you have a gen set rated for the same KW as your entrance equipment you will always be load shedding or overloading your gen set. A licensced electrician will not install such an arrangement. Shade tree electricians do it all the time. Not all generators laying around have a circuit breaker or one that works so then you fry it. Best thing, install a seperate small panel with the breaker transfer switch we are talking about, feed the utility power side from the same size breaker installed in your main panel that way you do not have to tap the buss. Then move those essential loads to the new panel keeping the load within the bounds of your generator. I have been an elactrical inspector and keep up on the codes.

 

[BobRip]

Might be time to define what you call the general public. I watched many of the general public wade through waist high water in N.O . ( I 'm local ) after Katrina assuming downed power lines in the water were safe .

One of my neighbors cut a tree with power lines in it after Irene. It was blocking our exit to the neighborhood.

 

[JB4310]

One of my neighbors cut a tree with power lines in it after Irene. It was blocking our exit to the neighborhood.

I would probably do it carefully, depends on if it was a primary or secondary. I think it's getting kinda silly, after Irene I went to a customers house to look at a job, her service entrance wire was down at the end of her driveway.

The power was out on the whole street for 3 days, the power company sent a contract worker there to "guard" the wire. this woman sat there in a lawn chair with a hard hat and yellow vest for 3 days. Wouldn't let this lady leave her house.

I thought to myself, If it were me I'd get a broom and sweep that big "extension cord" out of the way.

As far as live electricity in water, I see it all the time, these open grated electric manholes filled to the top with water and kids playing on top of them, must not be as bad as we think it should be.

I dropped the female end of a live extension cord into a sump pit filled with water just the other day, scared the heck out of me thinking something was gonna blow up, but nothing happened, just pulled it out, didn't even trip the breaker.

I greatly respect electricity, only been shocked once, but I don't fear it so much that it prevents me from working around it.

JB.

 

[Mace Canute]

I think its safe to say the general public never assumes a downed line is safe.

From experience I have to disagree.

I'd say almost only retired pole cats and copper thieves might assume such a thing!

That's true about old retired Linemen but copper thieves?? Doubt it! Most copper thieves aren't as smart as the general population from what I have been able to glean over the years. The amount of work they do for the few bucks most make is more than they would have to do at a real job, but I guess they convince themselves otherwise.

Most of the public can't tell the difference between phone wires and the power lines, and most of them wouldn't touch a piece of power line that wasn't even connected on the ends.

That's true about differentiating between the lines but as far as touching them, see above!
People seem to always call a pole with wire on it a telephone pole. Why I don't know. The only time it's a telephone pole is when there is JUST telephone wire on it...all other times the electrical utility owns the pole and rents space to the communication utilities and it is properly called a power pole.

And Mace since you've been out there. have you ever actually seen it, a home generator energizing any part of the public utility lines??

I've heard of it happening but I never personally saw it. WHY that is such a rare event is open to much conjecture...it might be that the Sask Power customers are too cheap to actually buy generators or the outages (which are rarely of any real duration) are just too short for most people with a generator to bother hooking it up if it isn't absolutely necessary to do so. I'd like to think that the people who do have generators are also intelligent enough to have a proper hook up that prevents any backfeeding situation.

 

[timswi]

My neighbor tried to backfeed without shutting of his main. The portable generator would only run for 2 seconds and stalled. Once he threw the main it worked fine. We only have 2 houses per transformer on a 1000 foot rightaway, he was at the beginning.

The only wire I can see being energized is a wire broken at the transformer/pole and still attached to the meter if the main is on..Otherwise the feed is infanite to the rest of the neighborhood, and no non-nuclear generator can handle powering everyone else.

Not advocating this, although I have back fed my house only with no issues.

 

[grsthegreat]

hehe, this is the 4th or 5th post like this that Ive seen in the past month. Bottom line is its illegal to back-feed a house without the use of an interlock. Period. That being said they are available for under $20 at most wholesale houses for a basic butterfly interlock (for small subpanels) to about $100 for an intricate heavy duty unit (for main panels). Siemens now has a panel with a built in generator subpanel that can handle either a manual trasfer switch OR any brand of automatic transfer switch controls, and costs about $300 (wholesale)

 

[ray66v]

No question a home generator trying to power the grid, is going to be over loaded. And, I certainly would expect it to simply crap out.

There also has to be a failure to follow what I thought was the standard procedure, that you treat every wire like it is hot, when your working around them.

However, in previous discussions, there have been many posts that indicated there have been injuries to linemen from back feeding. Some cited published accounts.

So, there is a real danger here.

Downed wires becoming energized, and injuring bystanders is another possibility to consider.