Generator backfeeding into utility lines

   / Generator backfeeding into utility lines #1  

JDgreen227

Super Member
Joined
Nov 2, 2003
Messages
8,275
Location
Central Michigan
Tractor
4210 MFWD Ehydro--'89 JD 318
I was remembering this morning about someone who told me how he rigged up his generator to plug into his 240 volt dryer outlet, thus energizing his service panel without having the expense of a transfer switch. He claimed that by tripping the main breaker in his service panel, the danger to utility workers was completely eliminated while using his method.

That was a long time ago, and I have sometimes wondered if the method he used was as practical and as safe as he claimed it was. Can anyone here tell me if it would work as he described, and in addition, if you tried his method and left the main breaker on, how far could the current from a mid size generator....say 7000 watts output, carry with enough amperage to endanger someone working on the lines?

DISCLAIMER: I am in NO WAY suggesting I would try a generator hookup by this method, and am in NO WAY endorsing anyone else try such a hookup. Thanks.
 
   / Generator backfeeding into utility lines #2  
Technically if all the connections are broken back to the utility, it would be safe. Generally, only the hots are disconnected. I read about an add on bracket that used a breaker to the generator and the main breaker. Only one could be on at any given time.
 
   / Generator backfeeding into utility lines #3  
It is completely safe, if you do it correctly, but I wouldn't recommend it and it is not legal. My dad and my uncle did something very similar except they did it with a dedicated breaker and power inlet. Two things can happen somebody turns on the inlet and you have a live male connector or somebody lights up a generator and does not turn off the mains. I have been trying to get them upgrade to an interlock kit because one day I am going to have to oversee their estates and that will never get past an inspection. An interlock kit does this but has a physical plate that prevents both breakers from being on at the same time. Incredible simple and way overpriced but worth every penny.

Generator InterLock Kit
 
   / Generator backfeeding into utility lines #4  
No, it's not safe for electrical utility workers. It relies on someones memory to actually throw the breaker . There is always the possibility that someone will forget or someone will "do the guy a favor" and fire up the generator for him without knowing that he has to throw the main breaker first.
 
   / Generator backfeeding into utility lines #5  
JD, Something else to think about. Linesmen don't rely solely on rules to keep them safe, they also connect substantial ground wires to sections they're working. These grounds have more than enough capacity to turn your generator into a one shot toaster should you accidentally improperly connect. MikeD74T
 
   / Generator backfeeding into utility lines
  • Thread Starter
#6  
JD, Something else to think about. Linesmen don't rely solely on rules to keep them safe, they also connect substantial ground wires to sections they're working. These grounds have more than enough capacity to turn your generator into a one shot toaster should you accidentally improperly connect. MikeD74T

Thanks, but I am sure I clearly stated I MYSELF have no intention of making such an unsafe, hazardous connection. Electricity scares me too much to attempt such a hookup. I had just remembered what someone told me a long time ago, after reading his funeral notice. No, he didn't pass away from an electrical shock....it was cancer.
 
   / Generator backfeeding into utility lines #7  
Thanks, but I am sure I clearly stated I MYSELF have no intention of making such an unsafe, hazardous connection. Electricity scares me too much to attempt such a hookup. I had just remembered what someone told me a long time ago, after reading his funeral notice. No, he didn't pass away from an electrical shock....it was cancer.

Wasn't trying to imply any potential wrong doing on your part. Your question has been asked & answered many times on TBN. A large portion of responses predict dire consequenses to linemen. In reality, although the open breaker protection is valid until human failure intercedes, the failure of a generator is more likely than injury to a lineman. This doesn't negate that injury to a lineman is far worse than death of a generator. MikeD74T
 
   / Generator backfeeding into utility lines #8  
There is a stiff fine and jail sentence for back feeding. Don't do it. Get the interlock bracket. I made one and it worked great. Last week I bought the commercial one. About 175 after shipping. Rediciously over priced, but I sleep better.
 
   / Generator backfeeding into utility lines #9  
There is a lot of good information available about back feeding lines. Its easy to do. I was considering this when we bought our first portable generator. From all the information that I have read, mostly from the generator manufacturer and the electric companies, I decided not to back feed the house.
 
   / Generator backfeeding into utility lines #10  
The $175 cost also includes two 2 pole breakers probably. I had an emergency panel already in my emergrncy panel when I bought the place. It only had a 30 A Generator feed breaker. Last winter I upgraded to 17.5 KW Gen and upgraded it all to a 50 A gen breaker. I did a post elsewhere with all the details in how to do it. The danger to the linemen is that after the gen power hits the utility power it goes through a transformer which ups the voltage to probably 12470 V, the normal utility distribution voltage. Yes the linemen ground what they are working on but they are human too. You would not want to be around if they forget to remove the grounding straps (I have). The big box stores have the kits for all the brands of breakers they handle. Remember you have to have a seperate panel for the circuits you want to power with the Generator as the kit is not available for the panel main breakers. You would need a manual transfer switch rated at the utility power supply or an automatic transfer switch. You can buy a small panel and a bunch of breakers for less than 1/2 the price of a 200A manual transfer switch. Autos are reserved for whole house generator systems and are really spendy. The genset has to be set up for remote start.
 
 
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