Return to the Electrical Wiring Forum | Post a Follow-Up

 o
Generator transfer switch connection

Posted by tew076 (My Page) on
Mon, Apr 9, 12 at 13:40

I recently purchased a Yahama EF2400iSHC invertor/generator to provide emergency power to a side-by-side refrigertor, lights, a couple of TVs, a few computers, a microwave and a toaster oven. I will probably power the refrigetor most of the time and power the others with whatever remains. The specs of the unit are below.

2400 watts max output
2000 watts rated output
16.7 / 20 amps @ 120V

I am planning to have an eletrician install a transfer switch. The generator only has two 5-20R, 20 Amp AC outlets. I found that most of the transfer switches and inlet boxes have L14-20 or L14-30 connections. Is it safe or recommended to buy an adapter to connect the Yamaha to the transfer switch by one of the 5-20R outlets? If this is problematic I may return the EF2400iSHC and get a Yamaha EF3000iS as it provides more power and can connect to a transfer switch without an adapter.


Follow-Up Postings:

 o
RE: Generator transfer switch connection

I would NOT connect a generator that small to a transfer switch/panel.

With what you are connecting you can run only the refer alone, or the micro alone, or the toaster alone. Some lighting and maybe a TV or computer or two are not that big of a load.

A 2000W generator is TINY in the scope of things as far as a home goes. Personally I would only use something that small with cords. Even a 3000W units is small for an application like this.

If anything I'd go with the 3kW and still be VERY diligent as to what you run simultaneously.


 o
RE: Generator transfer switch connection

OK. Thanks for the quick response. I still have a couple of weeks to think about returning the EF2400 unit. In addition to the EF3000iS I am also considering a couple of Yamaha EF2000iS units connected via parallel cable to get 4000 watts of maximum output. It looks like I would still need an adapter though as it looks like the parallel cables have a 30 Amp RV connector.


 o
RE: Generator transfer switch connection

Your side by side refrigerator will take about half the generator output in steady state but a bit more when the compressor fires up. The toaster oven is the biggest draw there. Most of them will suck up almost the entire 2000W on their own.


 o
RE: Generator transfer switch connection

Unless you need one of the little quiet 2000iS for camping or something like that, buying two of them to get 4000W is flat out crazy.


 o
RE: Generator transfer switch connection

I have a similar situation with a Honda generator that only provides 120V. My plan (with the blessing of Reliance Controls tech support) is to tie the two hot wires inside the transfer switch wiring compartment to the single hot coming from the power inlet box. That way, both legs inside the panel will be hot.

All I need at any one time during an outage is the fridge, 32" LCD TV, two 60 watt lamps, and some cell phone chargers. My 2000 watt (peak) generator did just fine this way for about 8 hours during the last outage. I ran extension cords for that one, but now have a Reliance Controls transfer switch that I plan to install. With the switch, I will turn off the fridge if I need the toaster or a small window A/C (which is rated well under the peak load of the generator). I understand what petey_racer is saying but you CAN use your generator for a whole house but you can only have a few things on a time, as he stated.


 o
RE: Generator transfer switch connection

But to answer the original question, here is how I plan to go from the 120V to the power inlet box:

- Use 12/2 extension cord and cut off the female end. Add a L5-30r instead.
- Install a 30 amp 125V power inlet box.
- Run 10/3 Romex from the power inlet box to the transfer switch. Leave one hot screw empty in the power inlet box because the 12/2 cord is only supplying one hot wire.
- Connect the hot wire in the 10/3 Romex to BOTH black wires inside the transfer switch wiring compartment.

You may be wondering why I'm bothering to run 10/3 instead of 10/2 if I'm only using 120V. Just in case I upgrade to a 240V generator in the future. That way, I only have to run the long Romex once. If I do upgrade, I'll have to buy a new power inlet box with a L14-30 connector instead. No big deal to change that. Just a little extra money.


 o
RE: Generator transfer switch connection - correction

CORRECTION: in the third step above, the 125V power inlet box has only one hot screw. Sorry, I was rushing when I wrote that. I am capping off one of the unused hot wires in the 10/3 Romex instead.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Electrical Wiring Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here