I don't talk about it much because few people would understand, so therefore many would assume I was doing something dangerous, or immoral, or unpatriotic... but that is exactly the way my CCK has been wired since the beginning. It is one of the ways that we survive just fine on 4KW (or even less when the Onan fails us).
Vaughn
As long as any idiot can just buy a genny over the counter, then there are going to be backfeeds. When it comes to "how often anyone suspects", in my case I suspect that it is pretty common.
That's why I did find it a little suprising that linemen have been injured/killed by such backfeeding, unless they weren't following SOP. I could just about imagine it happening with lv lines, eg the line from local transformer to the house. But I couldn't imagine an engineer working with an hv line taking short cuts. You don't get a second chance with 11kV, or whatever equivalent voltage you use.
It is not just toy gensets that are available - my local toolhire shop will quite happily let anyone hire a 20kVA baby and tow it home...
There are always idiot linesmen out there as well as idiot generator installers.
Yes, they have a protocol that insures safe handling but many are not the sharpest knives in the drawer either and using the procedures can take away from their macho manhood sometimes.
Was that before or after you astronaut programme employment?
Bruce In most homes in the US and Canada what you suggest can lead to circuit failure and fire. Most homes contain at least one multiwire branch circuit. In order for the neutral of such a circuit to not overheat and fault out there must be a voltage between each ungrounded conductor and the grounded neutral conductor and a voltage between the ungrounded conductors. When a generator is fed into a homes wiring using a bootleg Edison rather than a true Edison circuit the voltage between the two separate ungrounded current carrying conductors is zero so the current on the shared grounded current carrying neutral conductors is the sum of the current on the two ungrounded current carrying conductors that it serves. In the real Edison Circuit arrangement the the current in the grounded current carrying neutral conductors is only the difference in the current flow of the ungrounded conductors of the multi wire branch circuit.
-- Tom Horne
In HV (V>=66 kV in Europe) they use grounding switches, besides opening breaker and disconnect switches, that connect each leg to the ground not only of accidental breaker closing but also induced voltage of parallel lines.I have also seen a voltage tester for MV when some linemen did something in MV in my neighborhood.Normally in MV (V>=15 kV
When the crew is working 16-hour days for multiple days, I suspect that SOP is occasionally not followed, either as intentionalal short cut or more likely, just from being tired.
. . .
Well, I have done a lot of work on this since my original post. First of all, I did an audit of all the breakers and found out where they go and what leg they are on. With a little research, I found that with the older, larger-sized breakers, the legs alternate with every breaker. With the new, smaller-sized breakers, they also alternate, but there are two breakers in a single package that is the size of one of the old breakers.
After assigning the leg number to each breaker, I spot checked my results with a volt-meter by checking a number of outlets. If you get a
240V reading, then obviously, the meter is connected to opposite legs.Then I also did some math for load management. It turns out that I am very lucky. The load balancing is very good just like it is. I was prepared, though, to rewire some of the breakers if I had to. This wouldn't be very difficult.
Then I got lucky again and found a used Briggs & Stratton, Wheelhouse
5,550W at a local pawn shop for $389.95. It looks new and runs perfect and I checked the voltages with a test load (electric heater). This saved me about $800-$900 because I was going to buy a new 8000W generator.Now I have a new problem. This thing is very noisy! The first thing I'm going to try is installing an automobile muffler on it. Unfortunately, though, the flange and pipe and muffler are all one piece and I don't want to destroy the muffler by cutting the pipe. However, it looks like I got lucky again. I found a seller on ebay that is selling Briggs & Stratton flanges that will fit my engine. So, I'm going to give the automobile muffler option a try.
If that doesn't work, there's a website that shows a method of enclosing this kind of generator in multiple boxes. If I have to, I guess I'll do that. That website, by the way, is at:
Good job!
Yep, I think we told you about that.
Be sure to have a flexible connection connection between the muffler and the flange. Otherwise you will break the flange or the bolts that connect it to the engine. Of course, the muffler can only reduce the exhaust note; there is other noise...
Someone mentioned sandbags. Those coupled with (perhaps) a hedge sounds like a useable idea. Or perhaps concrete blocks stacked and filled with sand? I use Home Depot wooden fence. I nailed an extra layer of wooden pickets on it to make it double thick, and sealed it at the bottom so the noise can only escape at a high angle. Whatever you do, don't forget that cooling air must somehow get in and exhaust & hot air must somehow get out.
Vaughn
>
Sandbags?! That's an interesting idea. In doing some searching on Google, it looks like the drawback is that they rot with time. Dayton Bag & Burlap
Coincidentally, I have a rather large, 25-year-old sandpile that I would like to remove and cleanup. So, I could kill two birds with one stone.
I could, perhaps, build a small roof that would lay on top of the bags. Maybe I could make it out of heavy particle board and roll roofing. That would look better than simply throwing a sheet of plastic over the "bunker" to protect the bags from the sun. That might also provide some additional sound proofing. If I did that, I would still have the problem of sound proofing the open entrance that I would need to wheel the generator in and out of, though.
Nothing comes to mind at the moment for the entrance. So, I'll have to do some thinking about that. I suppose I could make an L-shaped entrance so that the sound would have to go around a corner to get out . . ."
Aren't they made of plastic these days? If a poly or nylon or kevlar bag rots in only a few years, why are they all worried about it filling up the landfills?
Well, there is that. :-)
THat's easy - point it away from the house. :-)
Just line the room with some cheap shag carpet remnants - maybe drive around and look for someone who's having their carpet replaced. Put up a chimney for the exhaust; that'll get the noise farther away, plus keep the exhaust fumes out of the intake, and out of the generator room! :-)
Have Fun! Rich
Rich Grise wrote: ...
Rot isn't exactly the right word. Ultraviolet light will cause most plastics to decompose over time. It's exposure to sunlight that is the problem.
Anthony
wow, i spawned alot of talk with my lineman electrocution post. :P
And about the transformer explosions... I really diddnt mean "explode" but if you try to run an old pole transformer backward after it's been running one direction for 10+ years, it may not like it and may fry some windings on it. But hey who cares, that's the power company's problem :)
Not true. A transformer does not care which direction it is passing power and (in 100% AC operation) has no memory of such things.
Vaughn
You're kidding, right?
I remember magnetic core memory, but I don't recall that power transformers had this property.
In article ,
What if the "some idiot" was one of these green types that has their own wind farm/solar panel setup that back-feeds spare power back into the grid?
It's always puzzled me what happens when you've got one person in a street with that kind of setup, and there's a cable break ... one person tries to power the whole street ... linesman gets zapped from the "dead" side of circuit etc ... mmm ... messy!
Who cares? You'll care when they sue you for damages!
You can easily blow up a transformer when your generator current exceeds the capacity of the transformer's secondary windings.
Joe, excuse me but that is a pretty strange statement. The transformer that feeds my house is very typical and it is big enough to supply 100+ amps @220 volts to four houses. Do you know anyone with a household genny big enough to damage something like that? My biggest unit could put a whole 30 amps on one
110 Volt leg (OK, perhaps 60 for a second or so before the breaker tripped).Vaughn
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