Generator to house ?


Old 10-25-08, 09:05 AM
Thread Starter
Join Date: Oct 2008
Location: SC
Posts: 3
Received 0 Votes on 0 Posts
Generator to house ?

I recently purchased an existing home that loses power somewhat often. The builder installed an outlet on the outside of the house that allows a generator to connect to the fuse panel. The outlet is a 20amp 125/250 4 prong locking type, and the generator breaker in the panel is a 30amp. I purchased a generator that has a 30 amp 125/250 4 prong outlet. What options do I have to get this to work?

I mainly want this to run some lights and a well (pervious owner indicated that his 5k generator ran the well fine).

Thanks in advance.
Sponsored Links
Old 10-25-08, 09:48 AM
waterwelldude's Avatar
Join Date: Jun 2008
Location: S.E. Texas
Posts: 1,042
Received 0 Votes on 0 Posts
As far as running lights. The 5000 is ok.
During our little storm we had here a while back. Power was out for two to three weeks. There were lots of people trying to run there wells with generators.
There were quit a few that were burnt up from low voltage.
Some generators that were supposed to be big enough to run the well, just weren't doing there job.

If you run the well with it. Be sure to have an electrician check the voltage at the pump, before you try to run the pump. Have them check it when the pump is trying to start. That is where the most voltage drop can be.
For most pumps. You are allowed 10% up or down.
More than that can hurt the pump.

Just somethings to look out for, when using a generator.

Old 10-25-08, 10:12 AM
Join Date: Oct 2008
Posts: 1,312
Received 0 Votes on 0 Posts
Did they also install a generator "transfer switch"?

On transfer switches...
Old 10-25-08, 01:26 PM
Thread Starter
Join Date: Oct 2008
Location: SC
Posts: 3
Received 0 Votes on 0 Posts
No they did not install a transfer switch. I asked about this during the home inspection, and was told that one was not required. I realize that puts the burden on me to disconnect the panel from the line in everytime I use the generator, which is ok until I can get the transfer switch installed next year.

However, what are my options on connecting the 30 amp generator outlet to the 20 amp inlet on the house? Worse case I could upgrade the swicth on the house, what guage wire would I have to have in the walls for this (running new wire in the wall may not be an option)?
Old 10-25-08, 01:44 PM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 21,119
Received 2 Votes on 2 Posts
I think you need to find out what the wire between the inlet (it is an inlet, not an outlet? That may not be the right term.) and the breaker is.

That will determine what you will need to change.

btw, although some of the Pro's don't like them, you might be able to install an interlock on your panel to prevent accidents.

Could you post the type and model of panel you have?
Old 10-25-08, 02:16 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,493
Received 33 Votes on 25 Posts
Until such time as you have an approved AND INSPECTED transfer switch, transfer panel or main breaker interlock installed you cannot even think about using this generator connection.

Without the means to positively prevent simultaneous connection of both utility and generator power you have an extremely dangerous situation. Use of such a connection is unlawful in every part of the entire United States no matter what "other" electrical codes may be in place.

Who told you that one was not required?

Last edited by Furd; 10-25-08 at 04:04 PM.
Old 10-26-08, 12:09 AM
ray2047's Avatar
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
The builder installed an outlet on the outside of the house
It must be a inlet. Is it male or female. If female it is WRONG and can not be used.
Old 10-26-08, 12:46 AM
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Received 0 Votes on 0 Posts
Unforetally.,, Those guys are correct and this is pretty serious matter that need to be address here.

Need a approved type of transfer switch or Interlock device { some inspectors will not approve this one }

What wire size between the inlet and the breaker box ??

The reason why I ask due somewhere along the way it is not done right.

This is a approved inlet box { there is other style will look simuiar to this }

For the transfer switch there are quite few diffrent verison to deal with it.

I will type in most common ones.,,

Manual Transfer switch

Automatic Transfer switch

But for manual tranfer switches there are quite few diffrent verisons but I will give you a quick summary of it.

subpanel transfer switch this set up can be used as normal or generator set up by useing two " main " breakers with interlock device{ this can be used in the main breaker location as well ( some inspectors or local code may not allowed this set up )}

Some peoples bring in pretty good number of extension cord and used for light, Fridge, Furance{ this is a tricky part here I will explain in diffrent time for this one }

Old 10-29-08, 11:27 AM
Join Date: Sep 2008
Location: Ohio
Posts: 13
Received 0 Votes on 0 Posts
Novice Goat, I recently installed a transfer switch and it was easy. If you search the web you can get better deals on these switches. Just do your homework and read all the generator questions on this site.
Old 11-01-08, 02:54 PM
Thread Starter
Join Date: Oct 2008
Location: SC
Posts: 3
Received 0 Votes on 0 Posts
Thanks for the feedback and additional insight on the transfer switch. It looks like I will probably go the interlocking device route.
Old 11-20-09, 08:02 AM
Join Date: Nov 2009
Location: USA - VA
Posts: 4
Received 0 Votes on 0 Posts
Easier Transfer Switch

I agree that you need to have a legal system and NEVER backfeed a panel without a safety device. I use to install the sub panel transfer switches but I found a much easier solution. There is a kit sold at that fits right on the front of your panel that keeps the back feed breaker and the main breaker from being on at the same time. The best part is you dont have to choose which circuits to move...just turn off the ones in your panel you don't want on... say the AC. They might be a bit pricey but they are quick to install and meet code. I put a link to their site below.


Generator InterLock Kit
Old 03-29-10, 07:25 AM
Join Date: Oct 2008
Location: Eastern Ohio
Posts: 27
Received 0 Votes on 0 Posts
Just for everyone's information, it is NOT unlawful EVERYWHERE in the US if you do not have a transfer switch. Where I live, I don't have to abide by any electrical codes. Our house was built in 2002 and we didn't even have to have an electrical inspection (one was done, but that's just because that's what the builder does). Because I will do it correctly when I do install a generator, I called our electric company and asked about installing a transfer switch. The guy told me straight out that it's a good idea, but it's not required and they can't make me put one in. He thanked me for asking about it and my plans to put one in.

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
Ask a Question
Question Title:
Your question will be posted in: