Generator and back feeding house

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Old 07-01-12, 05:00 AM
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Generator and back feeding house

Have picked up champion 7000watt running-9000 starting watts gen.It has one 220-30 amp,two 110- 20amp,plus a few other plugs.I want to run the two 110 back to a sub panel through a disconnect switch(kind that was used in the air conditioner (pull out at end of summer and turn upside down and do the same before summer so the unit won't run in winter )),That way I would back feed into main panel and turn on only circuits that I need,with a total of 40 amps for the 220 circuit. At this disconnect I would have a note to turn off main breaker to house before redoing disconnect. I just want to use the gen to power --lights,ref,freezer (unit not big enough to power central air conditioner,needs about 50-60 starting amps ). I understand I should make sure the two 110 lines are loaded as equal as possible.
The questions are 1-about a floating neutral or if gen has the neutral and equipment ground bonded.Not sure what that really means --read in another post on site
2-not sure about total amps out of gen.If both 110 are used then I believe its 40 amps max if both 110 used as a 220. Or is it only 30 amps like the 220 circuit.With this size gen I don't believe you can get more than say 40 amps at most.
I do understand that this might not be perfectly the best way to do it,but the most inexpensive. The gen will not be located any place near the mail panel,will be close to sub panel that I want to back feed from.
 
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Old 07-01-12, 05:26 AM
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I'll jump in ahead of the electricians and say that a hook up that has any chance of a back-feed is not safe and in some places illegal.
 
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Old 07-01-12, 06:23 AM
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You must ALWAYS use a transfer switch or interlock when feeding the panel. The panel must be fed through an inlet not a receptacle.. Your casual attitude and lack of knowledge could easily kill someone.

We will be glad to help you set this up safely but it may be better if you hire an electrician since you seem to not know the basics. If you give us an on-line link to the specs for your generator it will help the pros help you with your questions. Is the 240v plug on the generator 4-wire or 3-wire? Also please use proper paragraph spacings in your posts to make them more readable.
 

Last edited by pcboss; 07-01-12 at 07:17 PM.
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Old 07-02-12, 05:41 AM
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Thanks for taking the time to answer me. As usual I don't write down my thoughts as good as I would like.I was NOT going to POWER any sub panel or any thing else through a Receptacle (the person I'm helping wanted to do that). I guess Inlet (wire to a breaker) would be the word I was looking for.The only time I would use a receptacle is to get the power out of the generator.
1-I want to take the two hot leads from the two 110-20amps (from generator) and supply the breaker of an interlock.From what I understand I should get 40 amps from that (220),to power the house. Or would it be better to just use the 230 receptacle to supply the interlock breaker,for 30 amp circuit to feed the house.
2-Below is the web site and some info about the receptacle on the generator.I am still wondering about the floating ground or if gen has the neutral and equipment ground bonded.Not sure what that really means --read in another post on site

Read more: http://www.doityourself.com/forum/ne...#ixzz1zSqOTBZA




http://www.championpowerequipment.co...al-english.pdf

(5) 120 Volt AC, 30 Amp Twist-Lock Receptacle
(NEMA L5-30R) May be used to supply electrical
power for the operation of 120 Volt AC, 30 Amp,
single phase 60 Hz electrical loads.
(6) 120/240 Volt AC, 30 Amp Twist-Lock Receptacle
(NEMA L14-30R) May be used to supply
electrical power for the operation of 120
and/or 240 Volt AC, 30 Amp, single phase 60 Hz
electrical loads.
(7) 120 Volt AC, 20 Amp Duplex (2)
(NEMA 5-20R) May be used to supply electrical
power for the operation of 120 Volt AC, 20 Amp,
single phase 60 Hz electrical loads.
(8) Ground Terminal Consult an electrician for local
grounding regulations.
 
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Old 07-02-12, 07:01 AM
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It would be easier to use the 30 amp receptacle to power the inlet. I am not sure you would be able to interlock the 2 120 amp feeds.
 
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Old 07-03-12, 09:05 AM
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It is common to install one double wide breaker pair in normal branch circuit positions in the panel, where you would measure 240 volts between the breaker screws, and connect one end of a cable to the generator inlet (male receptacle) on the side of the house,a nd the other end to that breaker pair. This is backfeeding. But you may not wire that up unless the breaker pair has a cam or slider or lever interlocking device that prevents both it and the main breaker up top from being on at the same time.

Not all brands of panels and not all possible positions in the panel permit installing such a mandatory interlock.

Then you connect an extension cord between the inlet on the side of the house and your generator.

When the generator feed goes to the main panel, where neutrals and grounds are interconnected (bonded) the generator should not have neutral and ground bonded within it. When the generator feed goes to a subpanel only, where neutrals and grounds are not bonded, then the generator should have neutral and ground bonded within. However I would not (and you should not) pry apart a generator to remove a neutral ground bond; I would just use the generator as-is.
 
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