Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

Buying a new generator and cable compatible with existing transfer switch.

Buying a new generator and cable compatible with existing transfer switch.

Reply

  #1  
Old 02-16-13, 08:55 AM
Member
Thread Starter
Join Date: Feb 2013
Location: United States
Posts: 2
Buying a new generator and cable compatible with existing transfer switch.

Background:
My house came with a generator transfer switch already installed (manual transfer). There is an outlet on the back of the house to plug in the generator (I am attaching a picture of the outlet). The generator I was looking at (Amazon.com: DuroStar DS4000S 4,000 Watt 7.0 HP OHV 4-Cycle Gas Powered Portable Generator: Patio, Lawn & Garden) will definitely handle the load but has only 120V output. The outlet on the house is a 3 prong and has 250V 20A printed inside. I will only be powering 120V devices with the generator.

Question:
Will this generator work with my current setup, or what should I look for in a generator that will work? What cord would I need to hook the generator up to my current setup?

Name:  plug.jpg
Views: 1236
Size:  18.9 KB
 
Sponsored Links
  #2  
Old 02-16-13, 09:58 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,055
We would need to know how it is wired to be sure. The 250v is simply its maximum rating. Since it is only three prong one of which should be a ground it is probably 120v. Note that is not an outlet. It is an inlet. Is it marked L520?
 
  #3  
Old 02-16-13, 10:08 AM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
As ray stated where does that inlet go? A transfer switch? List that model..

Additionally that is the wrong inlet if its for 120v only. Should be an L5 @120v. That there is an L6 @ 240v.

 
  #4  
Old 02-17-13, 08:24 AM
Member
Join Date: Aug 2010
Location: USA
Posts: 118
I am guessing that the wrong inlet is installed on your house. A picture of your electrical panel would verify that.

While a 120 volt only generator can be used to power up the panel, the typical house panel is designed to accept 240/120 volts from the utility. Special precautions must be taken to hook up a 120V generator.
 
  #5  
Old 02-17-13, 08:31 AM
Justin Smith's Avatar
Member
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,546
Looks to me like a 6-20 inlet. You'd have to get a new insert and move some wires around to use it.
 
  #6  
Old 02-17-13, 10:50 AM
Member
Thread Starter
Join Date: Feb 2013
Location: United States
Posts: 2
Took a look at the panel and got some pictures of it. I believe the panel may be hooked up to feed both 120V and 220V appliances. However the 220V appliances would not be needed when the generator is running.

The inlet is wired into the transfer switch. The transfer switch is a Challenger D223NFC double throw safety switch. The inlet on the outside of the house is not labeled to indicate which type it is, although it looks similar to a few from the graph that was posted lawrosa.

Here are the additional pictures I took, thanks for all the help!
Name:  transfer switch info.jpg
Views: 661
Size:  28.6 KBName:  transfer switch outside.jpg
Views: 658
Size:  20.4 KBName:  transfer switch sticker.jpg
Views: 636
Size:  13.9 KBName:  transfer switch.jpg
Views: 744
Size:  27.2 KB
 
  #7  
Old 02-17-13, 11:06 AM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
Take a pic of the main panel nest to it and all the breakers please....
 
  #8  
Old 02-17-13, 02:24 PM
Member
Join Date: Aug 2010
Location: USA
Posts: 118
You have the wrong inlet. You need a 14-30 inlet. Regardless of weather or not you plan to use any 240V appliances, it would still be eaiser to feed it with a 120/240 generator. Do you have any multi wire branch circuits in your panel? If you do, you can't use a 120V only generator on those circuits.
 
  #9  
Old 02-18-13, 03:44 AM
Member
Join Date: Jun 2008
Location: VA.
Posts: 813
This whole set up is illegal due to the fact that the transfer switch was just cut in between the meter and service panel.

In order to use this transfer switch, an over current device would need to be installed between the meter and transfer switch,(all grounding and bonding in the disconnect) THEN 4-wire from disconnect to transfer switch, 4 wire from transfer switch to distribution panel(with grounds and neutrals separated) and a 4-wire generator inlet (L1430 or L1420)
 
  #10  
Old 02-18-13, 03:00 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
This whole set up is illegal due to the fact that the transfer switch was just cut in between the meter and service panel.
I'm curious. Do you have a reference for that? None of the transfer switches I've installed were after the MOPD. All were upstream of it. All passed inspection and are still performing well.
 
  #11  
Old 02-20-13, 04:23 AM
Member
Join Date: Jun 2008
Location: VA.
Posts: 813
I may have jumped the gun on my response. I was going on the notion of "equipment on the line side of a service".

After talking to an inspector yesterday, he said he would allow it since the main panel is directly adjacent to it.
 
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