Portable Generator Electrical Question

[Beltzington]

My generator is rated at 30-amps and has a 120/240 L14-20 4-prong locking connector, reading the Owners manual and looking at the wiring schematic it is not clear to me how much amperage each 120v leg will provide. Is each leg rated to 20-amps, 10-amps or is the total combined limited at 20-amps? I understand I can't exceed the generators total amperage rating but want to know what each leg could supply individually. It also has several other outlets but I am just unclear on the 240V outlet. My guess is the breaker will kick if the total load on both legs exceeds 20-amps.

 

[LittleBill21]

generally the 240v receptical has a separate circuit breaker, it would be rated at that, if it doesn't it will be whatever the highest rating is of the other 2 circuit breakers.

 

[RNeumann]

For a 240v 30a circuit each leg of the 240v is rated at 30a.

Is that what you are asking or are you asking about the 120v circuits?

Another option is to area photo of the spec sheet. We will get it from that.

 

[Beltzington]

Here is the wiring diagram -

Looking at 240 plug it looks like the two 120v legs (red and black) run thru two 20-amp breakers. Indicating a total plug ouput of 40-amps limited by the generator total output. Your thoughts?

 

[RNeumann]

Their’s not enough of the drawing to get a full picture. One plug looked like it had a 20a breaker and the other had a 30a breaker. I couldn’t see where the wires went off the bottom of the drawing.

Having 2 20a breakers feeding a 240v circuit makes a 20a 240v circuit. Not a 40a circuit. USA 240v is split phase- each phase has 20a on it. Adding the two phases increases the voltage- not the amps.

 

[Beltzington]

Thanks, I believe my questions have been answered. Each leg is protected by a 20-amp breaker, if total amp output of the generator was 40-amps I could provide a service panel with up to 20-amps at 240V or by splitting the 120V legs up 40-amps at 120V. Correct.

 

[ruffdog]

Here is an adapter that plugs into a 30a 4-prong that turns it into 2/ 15a 120v outlets.

https://www.walmart.com/ip/Camco-55438-PowerGrip-30M-2-x-15F-4-Prong-Generator-Adapter/54804134?wmlspartner=wlpa&selectedSellerId=0&adid=22222222227053103953&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=c&wl3=152955437896&wl4=pla-264733218605&wl5=9059952&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=54804134&wl13=&veh=sem&gclid=CjwKCAjwuO3cBRAyEiwAzOxKshyeb35UCXKtgvVejBy3B0xozED2fglqkEIwRcJMGdyeWE9Ru3dv5xoC7rkQAvD_BwE

 

[ruffdog]

But then, this adaptor says it changes a 30a into two 20a outlets. ?????????
3-Foot 3-Amp 125/25-Volt Generator Y-Adapter - Champion Power Equipment

 

[gary49]

You have 3 circuit breakers, according to the schematic. One 20 amp/120 volt single pole feeding a GFI receptacle which has a normal 120 volt receptacle downstream from it which is also ground fault protected, a 30 amp/120 volt single pole feeding a 30 amp/120 volt receptacle (generally used on shore power for a boat or to feed an RV) and a 20 amp/240 volt receptacle which you should use to plug in a cord to your emergency panel through a 20 amp 4 wire twist lock inlet adapter. Just make sure you have a breaker interlock or a double throw switch to make certain the generator power can't feed the panel at the same time as the normal power. I'm guessing your generator is rated for 4500 to 5000 watts, perhaps a 1000 watts more of surge power.

 

[RNeumann]

Thanks, I believe my questions have been answered. Each leg is protected by a 20-amp breaker, if total amp output of the generator was 40-amps I could provide a service panel with up to 20-amps at 240V or by splitting the 120V legs up 40-amps at 120V. Correct.

I think part of the confusion is how gens list their rating vs how a home is listed.

A home has say a 200a panel. That means each 120v leg has 200a for a total of 200a at 240v.

Sometimes the gen will say something like “40a gen”. Unfortunately that could be 40a at 120v. And if it will make 240v it’s only 20a.

So if you want to run multiple 120v items you will have 2 120v 20a circuits. Not one 120v 40a circuit.

The comment above about including the brand and model would help. Also, if you plan to backfeed a house panel their is more to the puzzle.