Generator Backfeed w/ Transfer Switch

Reply

  #1  
Old 01-01-11, 07:38 PM
Member
Thread Starter
Join Date: Jan 2011
Location: USA
Posts: 1
Generator Backfeed w/ Transfer Switch

I have a similar problem with backfeeding a generator.

I moved into a house that has a transfer switch for connecting a portable electric generator to the house, but there is no male plug to go from the house to the generator. I could splice a male-male wire to connect the generator to the house, but have read that this is unsafe. Is it safe in this case . . where there IS a transfer switch already installed?

Next question: If it is safe, how do I do it. The female plug on the house is a dryer-type plug with 4 receptacles. The female plug on the generator is a three-pronged plug for 120V (just like any power outlet around your house). So, 4 on 3 . . . how does it work?
 
Sponsored Links
  #2  
Old 01-01-11, 07:58 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
Wait there is a gen plug from your house to the transfer switch? This is 4 prong? And your gen only has a 3 prong house recepticle? The gen did not come with the house then and you need a bigger watt gen with a 4 prong 30 amp recepticle?

Let us know more and take pics.

Mike NJ
 
  #3  
Old 01-01-11, 08:04 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
I agree with Mike. Your generator is obviously too small to be considered for whole or partial house use. You will need 10-3 w/g cabling from the generator and a 4 prong 30 amp twist lock female for the transfer switch and a 4 prong twist lock male for the generator. If the generator does not have a twistlock 30 amp receptacle, don't use it.
 
  #4  
Old 01-01-11, 08:46 PM
Member
Join Date: Dec 2010
Location: usa
Posts: 243
I am very concerned with your setup......please post a pic of the switch. NORMALLY, you either use a transfer panel like a Reliance brand that has several 15 or 20 amp double throw switches in it that you connect to the circuits you want controlled. Then this is connected to generator by cord and plug, with two ways of doing that....Size of the panel must match generator. They offer some that take 125 volts amd then bigger ones. The OTHER way is a true generator double throw safety switch that wires into the main line and then would have a wire run from the switch to an inlet box that you would mount outside and connect to generator with cord and plug. There are do's and dont's for using a double throw switch as well. The switch needs to either feed your main panel or a subfeed panel, but must be rated at whatever your panel is as well as wire. if you have a 200 amp panel only then you must have a 200 amp rated switch. You might have a situation where a small sub panel was mounted with critical circuits in it and then maybe a 60 amp or 100 amp switch installed. The drawback is you have to have the proper generatpr or you might be able to run all of the circuits. NEVER, NEVER use a "dead man" plug (male/male) or connect your generator directly to any outlet such as a dryer outlet. You might visit Reliance Electric's web site to watch examples of some of this stuff, but post pics of the switch you are mentioning.
 

Last edited by JimElectric; 01-01-11 at 08:49 PM. Reason: modifying
  #5  
Old 01-01-11, 08:53 PM
Member
Join Date: Dec 2010
Location: usa
Posts: 243
  #6  
Old 01-02-11, 06:42 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
Jim brings up a good point. That is why they mostly use the twist lock connectors. They aren't common to the household set up. Dryer receptacles, etc. are, and could be mistaken for a connection, and inadvertently backfeed the main, causing injury or death to workers on the line. Jim's link is helpful. When the animation loads, it shows the one I use on the right.
 
  #7  
Old 01-02-11, 08:45 AM
Member
Join Date: Feb 2009
Location: USA
Posts: 323
I wonder why they would go through the trouble of a transfer switch with no inlet box??

Does it have one of the inlet boxes that are covered, could possibly look like a sealed box and could be deceiving.
 
  #8  
Old 01-02-11, 09:05 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
They all have inlet receptacles. However, some larger ones are hardwired.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes