Generator transfer


  #1  
Old 08-17-01, 06:57 PM
T
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I have a generator transfer switch wired to my main panel. Just to to be on the safe side...will turning off the main breaker during a power outage ensure lineman's saftey? I know the gentran is supposed to prevent back feeding but I'd like the added assurance of knowing the main breaker is a fail safe. thanks tim
 
  #2  
Old 08-18-01, 08:04 AM
Wgoodrich
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Transfer boxes when properly wired are a either or or situation. It operates on the principle that in order to turn power on to the utility power the generated power must have been disconnected in the switching action.

You might feel better and be better informed looking at the picutures and text sections in the following link explaining generator hook ups.

http://homewiring.tripod.com/generator.html

Let us know if it helped or you need more info.

Wg
 
  #3  
Old 08-18-01, 01:10 PM
T
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Thanks WG. The transfer switch is wired exactly the way the manufacturer specified. I guess my question is that as a fail safe turning the main breaker in the main panel off while the generator is being used would without a doubt stop the power being generated from going back to the electic lines feeding my house. It makes sence that once I turn the main off there is no chance of power making its way out of my house....Right?
 
  #4  
Old 08-18-01, 01:39 PM
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yes
 
  #5  
Old 08-18-01, 04:08 PM
Wgoodrich
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I tend to agree with meggar's yes but have doubt. Do not rely on the main only to protect the feed back you are concerned about. This feed back can and will kill if power feeds back onto the power lines primary wires.

A transfer box properly wired is a no choice method when you connect to the generator power source you simultaniously disconnect from the utility power.

If you don't install a transfer box approved for the purpose your liability will fly through the roof. I you just us a main of the main service rated panel to shut of or disconnect the contact to you utility lines, and if one person forgets to shut off that main then you just energized the primary lines.

Be sure to install the transfer box. It is the approved method and the only either or type of wiring design that requires the disconnetion of the utility power from the generated power.

Good Luck

Wg
 
  #6  
Old 08-19-01, 08:27 PM
RickM
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Cool

I saw something interesting the other day. The local telephone company was installing some kind of large powered box (4' X 4' X 6') which required a 30amp circuit to feed it. This was provided by a pole mount service, with a 30amp breaker feeding the feeder to this unit. The feeder landed into a 30 amp main breaker installed in a breaker panel within the unit.

The interesting thing was this unit has a provision for generator power, via a receptacle mounted on the side of the unit. In the event of a power outage, a portable generator could be brought in and connected to this receptacle.

I wondered about the use of a transfer switch, and upon looking at the breaker box, I noticed a metallic device installed on the 30 amp main breaker, which had an arm touching the handle. There was another arm that was touching the handle of another breker directly under the main, which was label "GENSET".

Because this unit did not have power yet, I turned the genset breaker to the on position, which made the arm pivot, turning off the main breaker. Get it? The genset breaker was on, the main off. I then turned the main on, and the genset breaker turned off.

There was no way that both could be on at the same time. This device seemed to have been made for this panel.

I thought this was a pretty good way to keep the problem discussed above from happening.

Has anyone else seen this setup?

Could be a faily cheap fix for a deadly problem.

Rick Miell
 
  #7  
Old 08-20-01, 04:31 PM
Wgoodrich
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Rick

The mechenism you are talking about is what I believe to be an intricate design that seems to be costly. Usually found in utility back up systems. I have not seen one anywhere else but phone companies. Kind of like having a linkage system within the panel using rods.

There is a very simple and accepted product that only costs about $20. I questioned the product because it was so simply made with such a simple idea.

I checked with UL and they said it was considered to be an accessory product for panels and listing, labeling, and testing was not required.

It has been used without complaint of working or failure, and the Utility companies were satisfied with it. If you want to see a hand drawn picture of it hit the link below. I am not trying to promote the product. Just saying in this area it seems to have become the principle transfer switching method used in this area due to the cost and simplicity of the product. Have you ever seen it used in your location?

http://homewiring.tripod.com/generator.html

Wg
 
 

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