# Replace NEMA L14-20 with NEMA L14-30?



## [email protected] (Mar 22, 2020)

Hey guys,


I finally broke down and bought a generator to hook up to the transfer switch that was on our house when we bought it. I thought i was good buying the generator with the four prong locking 240v plug. Half way through my 5 hour break in period I figured out which circuits on the transfer switch controlled the different things in the house. When I went to plug it in, the notch was wrong. ugh! The generator accepts NEMA L14-30 plugs.


Here's what I have:
The outdoor plug from the transfer box is NEMA L14-20:

















The wire is labeled as 10 AWG 4/C:

















The transfer switch says that it can accept 30 Amp:

























Question: *Can i just grab a new NEMA L14-30 end from the hardware store and replace that connector on the outside of the house?*

More info:
Generator: 6250-Watt Open Frame Inverter https://www.championpowerequipment.com/product/100519-6250-watt-open-frame-inverter/

Most of the circuits in play are lights and plugs. One TV, two refrigerators and several lights. E and J (2 * 30 amp) circuits are for the well pump even though the main panel has two 20 amp circuits for the the same.. No hot water or furnace and AC. We are an electric household without natural gas or propane. Furnace is geothermal with electric coil backup that is not being considered for the generator at this time.

Let me know if i missed anything. I know just enough to be dangerous.


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## ToolLover (Jan 13, 2020)

So, I am going to respond to what I would do if I were in your situation.
First you have a flexible stranded #10 cable with 4 conductors.
That stranded cable exceeds the 30 amp conductivity you require because it is stranded wire.
The Nema L14-30 should be just fine, and I would prefer it over the L14-20 you have presently.
Add to that, your generator is only good for 26. amps @ 240 VAC.
I have the same twist lock 30 amp plug and the same cable that supplies my home for the Honda ES6500 which is a 26 amp generator also.
On a positive note, that is a good transfer switch.
You should be careful not to load the generator to max. 
Be selective when you turn on circuits.
That 30 amp could be a load with other circuits added.
Take note of the meters on the panel.
The meters tell you the wattage loads. but I could not see the markings on the meter faces.
Now to something I noticed about the TS (Transfer Switch)
The flex is the feed from the breaker panel to the TS.
That #10 cable is obviously from the generator feed.
The connection to the TS is pinching the #10 cable.
I would change that to a wall mounted male plug rated for 30 amps.
Having a cable premanently mounted from the surface TS is inviting trouble.
Not only is it pinched, it will eventually work loose.
Others may have different ideas, but 30 years industrial experience is all I have to offer.
Add to this a note: Do not use ethenol gas and always use an addative for all stored gasoline.


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## drmerdp (Apr 10, 2018)

Need to clarify something first. I feel like i'm missing something from your description and pictures.

Is the cable with the L14-20 plug directly wired into your transfer switch? 

If it is... Then Yes. You can buy a L14-30p connector and simply replace the 20amp connector.


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## ToolLover (Jan 13, 2020)

drmerdp said:


> Need to clarify something first. I feel like i'm missing something from your description and pictures.
> 
> Is the cable with the L14-20 plug directly wired into your transfer switch?
> 
> If it is... Then Yes. You can buy a L14-30p connector and simply replace the 20amp connector.


First picture: Look at the bottom left. The cable is wired directly into the TS.


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## iowagold (Jan 22, 2020)

a couple of things I would do is add a 35 amp 240 volt breaker between the inlet and the transfer switch...
also step up to 8/4 soow cable then put on the L-14/30 plug..

how long is your cord run from the transfer switch to the gen set??
I am Looking at extended run times and hot days...
the hd 8/4 cable is a good idea!
as well as an extra layer of protection of the extra inlet breaker... 
reason I do not see a breaker for the big outlet on the gen set..

those marine push button breakers some times do not work over time as good as the square D lever breakers.
you might want to have a few of those in the spare parts bin..
and get the water proof version.


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## ToolLover (Jan 13, 2020)

I have not seen the generator, but I am sure it has a 30 amp breaker ahead of the 240 receptacle.
So, a 35 amp breaker would be just a useless inline layer of protection.


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## iowagold (Jan 22, 2020)

yup on the 35 amp.
it is a just in case protection for the inlet only. not for the gen set.
I did not see any breaker on the 240 for the gen set.
most of the gens have a lever style breaker for the 240..
unless it is an auto reset inside the gen case or covers..

I guess it were all mine I would upgrade the outlet on the gen to a 50 amp twist lock and run rv cords..
that way the cords could be used for something else.

so many of these gens are running way too close to rated on the plugs and sockets...
we deal with this on the construction sites with saws on 20 amp plugs and sockets..
a bit of dirt or wear and you have a bad connection below the rated..

let along if you get the import stuff that is metric and not nec rated..
some of the contacts just are not right.. even out of the box.
I like 20% to 50% larger than you need..
then you have a bit of room for bad things...

I just replaced 4 on the push button breakers on a gen this am that were bad.
I used the good sea sense marine breakers and the matching wx resistant covers.

running a gen with out a gen tent shelter in the rain is just a bad idea..
here is the link to his gen again
championpowerequipment.com/product/100519-6250-watt-open-frame-inverter/


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## drmerdp (Apr 10, 2018)

That generator has a overload reset feature. Looks like it’s a restart to reset.

8/4 cord is a bit overkill for a 20 amp 240v generator, unless the cord is very very long. Which he has not detailed.

That being said, I like upsized conductors on generator inlets. Voltage drop is the enemy. Big conductors is the solution.


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## iowagold (Jan 22, 2020)

this is a 6250-Watt genset so 26.04 amps at 240
I stand by the 8/4 cord... best choice
that allows for hot days and surge.


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## iowagold (Jan 22, 2020)

oh yea at least 20 foot min to the gen set but more like 30 to 40 feet in reality.
or longer..
remember the gens need to be away from doors and windows..
and outside.
grin.

I never run any thing 240 with less than 6/4 at a min..
but then I like to be able to connect to larger honda eu7000is gen if the client upgrades.

40 to 60 feet total runs on my systems...
that is why I like 6/4 soow for the inlet and good 6/4 for the inside wire.
plenty of room for these 110 deg+ hot summers

and spend the money once..
I do not like to have to buy it twice.
buy the good stuff and then you are done.


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## [email protected] (Mar 22, 2020)

You guys rock! Thank you for all of the useful information.



ToolLover said:


> The flex is the feed from the breaker panel to the TS.
> That #10 cable is obviously from the generator feed.
> The connection to the TS is pinching the #10 cable.
> I would change that to a wall mounted male plug rated for 30 amps.
> Having a cable premanently mounted from the surface TS is inviting trouble.


I thought that was wonky. I will look into a wall mounted male plug!




drmerdp said:


> Is the cable with the L14-20 plug directly wired into your transfer switch?
> 
> If it is... Then Yes. You can buy a L14-30p connector and simply replace the 20amp connector.


It is directly wired into the transfer switch.




iowagold said:


> a couple of things I would do is add a 35 amp 240 volt breaker between the inlet and the transfer switch...
> also step up to 8/4 soow cable then put on the L-14/30 plug..


The cord is ~20 ft. Thanks for the suggestions. I will consider the 8/4 and see if there is a breaker on the gen already for that receptacle.



iowagold said:


> I guess it were all mine I would upgrade the outlet on the gen to a 50 amp twist lock and run rv cords..
> that way the cords could be used for something else.
> 
> so many of these gens are running way too close to rated on the plugs and sockets...
> ...


Replacing with a 50 amp twist is very interesting. And does add some flexibility. I will look into that later for sure. In general i like the idea of overbuilding and buying once. In this case the cord is not the weak point and would be acceptable, i presume? I think it goes without saying that I still need to be aware of the loads i am applying so as not to overload.

This TS was already here and has a platform for the gen already. I will make sure that a tent is in the blackout kit. i will probably overbuild that as well and maybe have something more permanent. I am in a rural environment.


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## iowagold (Jan 22, 2020)

the cool thing on a 50 amp inlet is if you change gen sets or rent or borrow another
you have a good setup already done.
less of a scramble for power when things hit the fan.... or go bad..

if you over build you never have to worry about the super hot summer days and extended gen run times of weeks on end on gen set...

lets face it... it has been hotter almost every year... at least here in the Midwest...
storms are brutal!!
nice to have a safety net of a gen set for one less thing to worry about!!

when you do settle in on your gen set you plan on running..
buy spare parts like 1 pull rope, a couple of spark plugs at a min, good oil, and a couple of spare air filters..

plan on oil change every fall if it is not used... and if it is to run on gasoline,
stabile on the fuel and if you have to use ethanol make sure you drain the whole fuel system when you are done..
including the fuel bowl..

if you can run the gen on no ethanol... I double dose the unleaded with stabile and it stays good for over 4 years here when stored in a good dry cool place.
I have some here I have been testing that is at 10 years now..
the trick to super long fuel storage is a cool dry place with lower than 10% humidity.. then when the cans vent they do not suck back in moisture..
and a tank that will not rust or corrode.

I am liking the idea of LP or natural gas for primary fuel and a gen set that will do tri fuel for flexibility when things go bad..
LP if the tanks are stored right and the lines are done correct.. is a good choice if you are remote and can store the LP right..
but it has a down fall if the tank gets a leak or same on a berried hard line then you are out a load of fuel...
but the LP has more energy per cu foot... than the natural gas..

I went natural gas here in town for primary gen fuel..
just so I do not have to store a bunch of fuels on site...
and so far it is working out good.


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