How many total Amps on a L14-30 cord at 120 vac

[dkoldman]

How many total Amps on a L14-30 cord at 120 vac and is it safe to feed 120v through each hot leg (L1 & L2) without concern with overheating wires or any issues with neutral?

Here is why I ask?

I have a 30amp 7500 watt Connecticut Electric HOME transfer switch. It works fine and I have had for 10 years. I use a portable 3500 watt generator that is 120 volt output only. I have an adapter on generator L5-30 to L14-30 to mate with the cord that feeds the transfer switch in garage with input of L14-30

In ten years the generator breaker may have tripped 5 times? Very very rare but it has tripped where I had to reset.

What I want?

From watching all of the talk about the F-150 EV power, I want to add a L14-30R receptacle in my electrical bay ( I have already bought this part). I have Onan 5500 with two 30 amp breakers. So my plan is to wire L1 to X and L2 to Y along with ground and neutral

I am thinking I will now have 5500 watts total capacity or 46 amps or so? But I will actually be under 30 amps 99% of the time.

Is this safe?

Note: The Switch is already balanced as it was balanced for the portable generator.

[DavidM]

30 amps, duh! That is the rating of the connector. The cord could be anything from 10 gauge on up, depending on how far it has to go to limit voltage drop. How long do you have to go?

David

[dkoldman]

Originally Posted by DavidM

30 amps, duh! That is the rating of the connector. The cord could be anything from 10 gauge on up, depending on how far it has to go to limit voltage drop. How long do you have to go?

David

50 feet total

I have a 10 ft L14-30 cord from Connecticut Electric that came with the Transfer Switch; and a 40 ft L14-30 cord that I bought professionally made.

Here is my Transfer Switch
https://www.amazon.com/EGS107501G2KI...99583010&psc=1

I removed both double poles so all 10 circuits are wired for 120vac. It works really well and it balanced. During a power outage we turn all circuits on and do like normal although none of the 240 stuff has power.

Hard to believe my Onan 5500 ( two 30 amp breakers) cannot work with L14-30 cord (wires).

[jerichorick]

Originally Posted by dkoldman

50 feet total

I have a 10 ft L14-30 cord from Connecticut Electric that came with the Transfer Switch; and a 40 ft L14-30 cord that I bought professionally made.

Here is my Transfer Switch
https://www.amazon.com/EGS107501G2KI...99583010&psc=1

I removed both double poles so all 10 circuits are wired for 120vac. It works really well and it balanced. During a power outage we turn all circuits on and do like normal although none of the 240 stuff has power.

Hard to believe my Onan 5500 ( two 30 amp breakers) cannot work with L14-30 cord (wires).

What am I missing here. What 240 stuff? Your generator has 2, 120VAC in phase outputs. Your coach uses 120VAC only. If you loose your neutral and 240VAC is applied to your service panel strange things will happen to your electrical system. I lost a A/C controller when this happened to me. The coach 120VAC circuits will work just fine in phase or at 180* out, as the commercial grid is.

[dkoldman]

Originally Posted by jerichorick

What am I missing here. What 240 stuff? Your generator has 2, 120VAC in phase outputs. Your coach uses 120VAC only. If you loose your neutral and 240VAC is applied to your service panel strange things will happen to your electrical system. I lost a A/C controller when this happened to me. The coach 120VAC circuits will work just fine in phase or at 180* out, as the commercial grid is.

You are Missing Post #1

Specifically....

Here is why I ask?

I have a 30amp 7500 watt Connecticut Electric HOME transfer switch.

The 240 stuff is in my Home's main breaker panel and NOT wired to my Home's Transfer Switch. (240 Stuff at home is Pool equipment, Dryer etc)

So back to intent of my question is to find out if possible to safely wire my Onan 5500 to power my 30 amp Home Transfer Switch via a L14- 30R supply cord?

[Dennis4809]

L14-30 is a 30 amp twist lock connector not a cord. For the 30 amp rating of the connector, it would typically be wired with 10 gauge wire. However, a longer run might call for 8 gauge wire.

[dkoldman]

Originally Posted by Dennis4809

L14-30 is a 30 amp twist lock connector not a cord. For the 30 amp rating of the connector, it would typically be wired with 10 gauge wire. However, a longer run might call for 8 gauge wire.

Yes and that is the QUESTION.

Please read Post #1.

The question is... is there a safe way to wire a Onan 5500 to a L14-30. Specifically a L14-30R.

Presumably if there were; you could then take a standard L14-30 Cord and plug into the female receptacle with male cord end, twist lock and do the same pugging into the male receptacle with the female end of the cord.

Again the question is does ANYONE know of a safe way to take two 30 amps circuit feeds from an Onan 5500 and wire to a L14-30?

[DavidM]

Part of your original question was how much current a 30 amp connector can carry. This question was answered by me and others above, 30 amps.

Your question immediately above is how do you wire it safely to your RV generator. Assuming the 30 amp legs from your generator are protected with 30 amp breakers, then you just wire the new connector to one of the legs downstream of the breaker. The generator will then be unbalanced- all of the load will be on one leg, but that should not be a problem.

You can't tie both legs together to get 60 amps. That would short the generator out. But since you only have a 30 amp connector, protected by a 30 amp breaker, then 30 amps is all you are going to get. Try managing the load so you don't exceed it.

There are ways to get the full output of your generator, but that takes a different 220V connector, a 220V, 3/1 cord and a different transfer switch or two transfer switches, one for each leg.

David

[dkoldman]

Originally Posted by DavidM

Part of your original question was how much current a 30 amp connector can carry. This question was answered by me and others above, 30 amps.

We don't agree here.

My original question is / was...

How many total Amps on a L14-30 cord at 120 vac and is it safe to feed 120v through each hot leg (L1 & L2) without concern with overheating wires or any issues with neutral?

Your question immediately above is how do you wire it safely to your RV generator.

My original question also included the safety component because that was nature of my post?

Assuming the 30 amp legs from your generator are protected with 30 amp breakers, then you just wire the new connector to one of the legs downstream of the breaker. The generator will then be unbalanced- all of the load will be on one leg, but that should not be a problem.

This was my 1st thought and plan, but I was told by Onan and few others that an unbalance load could damage windings? I don't know.... thus my question and posts to find out if there was a safe way to do. Seems like last few posts seemed more about questioning my question until this paragraph which at least confirms understanding of what I was seeking help with all along.


You can't tie both legs together to get 60 amps. That would short the generator out. But since you only have a 30 amp connector, protected by a 30 amp breaker, then 30 amps is all you are going to get. Try managing the load so you don't exceed it.

I never wanted or intended to get 60 amps, I only have a 30 amp transfer switch, 30 amp cord, plus all I need is 30 amps. Just not sure it is safe way to do so

There are ways to get the full output of your generator, but that takes a different 220V connector, a 220V, 3/1 cord and a different transfer switch or two transfer switches, one for each leg.



David

I am going to conclude that it is not safely nor practically possible. I just found it VERY surprising that my Onan 5500 could not simply do what what my Sinemate 3500 has done for 10 years to feed my Home Transfer Switch. I am not gonna screw around with anything questionable on my RV Onan 5500; I was simply trying to ensure I had not missed something simple.

All posts to assist have been appreciated

[jerichorick]

Originally Posted by dkoldman

You are Missing Post #1

Specifically....

Here is why I ask?

I have a 30amp 7500 watt Connecticut Electric HOME transfer switch.

The 240 stuff is in my Home's main breaker panel and NOT wired to my Home's Transfer Switch. (240 Stuff at home is Pool equipment, Dryer etc)

So back to intent of my question is to find out if possible to safely wire my Onan 5500 to power my 30 amp Home Transfer Switch via a L14- 30R supply cord?

Now I understand. Bottom line from my above answer? NO. The 5500 does not produce 240VAC. For emergency loads such as refrigerator, freezer, lights and gas heat the answer is YES.
Each of the essential loads would have to be wired through the transfer switch. When the generator is running, and the switch is operated, the power from the generator would operate the loads connected to the switch, but only up to 45A total.
Because this is a L1/L2/N arrangement the cord is not a problem. The connector is rated for 30A but the 6AWG is good for 95A.

[Morich]

I've not lokedat all the postings and I'm late to the game but there may be a way to get down what you want, if I understand the why.

Sounds like you would like to run the important house items from a single 30 amp source?

I rewired the house breaker panel to do this as Idecided the Air would be considered not critical while heat, frig, freezer and lighting, etc. would be vital.

Looking at the home breaker panel, it is split in different ways on different brands but there is almost always two seperate buss bars for the two hot sides of the 220 coming in. On mine, the even numbered breakers are on one leg and the odd on another, so getting the vital moved to one leg and the non-critcal to the other was all that was needed to set up feeding the critcal with one 30 amp feed comming in.

To do this, I first went through the entire house to ID ALL the electrical items, not just those I wanted to feed, as a way to preplan what I wanted to move and how to balance the load a bit at the same time.
I may have had an easier time switching the wiring around as this house was wired by an electrician as a personal part of the contruction and he did lots of "extra" wiring that most houses don't get. Things that make the house work better but are not done normally because they are not required by code.

So if there is a way to spilt the two 30 amp from the generator(?) and only use one to the housewhere then you have moved wiring wround to feed that 30 amp to the vitals, that willl be safe and the cord is fine as it is only used to carry the one single 30 amp.

I think I see but admit to being a bit rushed at the moment.

[dkoldman]

Originally Posted by jerichorick

Now I understand. Bottom line from my above answer? NO. The 5500 does not produce 240VAC. For emergency loads such as refrigerator, freezer, lights and gas heat the answer is YES.
Each of the essential loads would have to be wired through the transfer switch. When the generator is running, and the switch is operated, the power from the generator would operate the loads connected to the switch, but only up to 45A total.
Because this is a L1/L2/N arrangement the cord is not a problem. The connector is rated for 30A but the 6AWG is good for 95A.

I am not sure you understand. I am not trying to get 240vac

I don't need 240vac. All 10 circuits on my Home Transfer Switch are connected to 120 VAC 15 or 20 amp circuits. But none f that is or was my question.

Let try a different approach,

I have a Portable 3500 watt Generator today. It had a L14 - 30R receptacle. I use a STANDARD L14-30 cord and it has worked FLAWLESS for 10 years and still does today.

Now, I was just wandering IFFFFFF... I could somehow, SAFELY wired my existing Onan 5500 to it's own L14-30R receptacle in the Electrical bay of RV to feed the same Home Transfer Switch?

I am concluding No, so it is no big deal so thread can stop. It just would have been nice if I could supply the house with 30 amp power from the Onan 5500. I am not going to pursue wiring just off one leg out of concern with unbalanced load to the windings.

[dkoldman]

Originally Posted by Morich

I've not lokedat all the postings and I'm late to the game but there may be a way to get down what you want, if I understand the why.

Sounds like you would like to run the important house items from a single 30 amp source?

I rewired the house breaker panel to do this as Idecided the Air would be considered not critical while heat, frig, freezer and lighting, etc. would be vital.

Looking at the home breaker panel, it is split in different ways on different brands but there is almost always two seperate buss bars for the two hot sides of the 220 coming in. On mine, the even numbered breakers are on one leg and the odd on another, so getting the vital moved to one leg and the non-critical to the other was all that was needed to set up feeding the critical with one 30 amp feed coming in.

To do this, I first went through the entire house to ID ALL the electrical items, not just those I wanted to feed, as a way to preplan what I wanted to move and how to balance the load a bit at the same time.
I may have had an easier time switching the wiring around as this house was wired by an electrician as a personal part of the contruction and he did lots of "extra" wiring that most houses don't get. Things that make the house work better but are not done normally because they are not required by code.

So if there is a way to spilt the two 30 amp from the generator(?) and only use one to the housewhere then you have moved wiring wround to feed that 30 amp to the vitals, that willl be safe and the cord is fine as it is only used to carry the one single 30 amp.

I think I see but admit to being a bit rushed at the moment.

See my post #12, your last paragraph get close to what I would need if it would work, but Onan says load would be unbalance

My house has been wired with a 7500 Watt 30 amp Home Transfer Switch for 10 years. It works well. I have only wired it to 120 vac circuits although it has capability of 240vac. I hate to even mention 240vac because some get confused and run with that. I don't want or need to 240vac. I only wanted to see if there as a way to SAFELY without RISKS to make my Onan 5500 does what my existing 13 year old Sinemate 3500 does today

How did I get in this Rathole

Last year during Texas freeze I had to refuel my portable generator every 7 hours and that included middle of the night, it worked but a PITA, I was just trying to see if I could connect wiring for my existing L14-30 cord to my Onan Generator via a new female receptacle without a safety or damage concern to my RV.

[jerichorick]

Originally Posted by dkoldman

See my post #12, your last paragraph get close to what I would need if it would work, but Onan says load would be unbalance

My house has been wired with a 7500 Watt 30 amp Home Transfer Switch for 10 years. It works well. I have only wired it to 120 vac circuits although it has capability of 240vac. I hate to even mention 240vac because some get confused and run with that. I don't want or need to 240vac. I only wanted to see if there as a way to SAFELY without RISKS to make my Onan 5500 does what my existing 13 year old Sinemate 3500 does today

How did I get in this Rathole

Last year during Texas freeze I had to refuel my portable generator every 7 hours and that included middle of the night, it worked but a PITA, I was just trying to see if I could connect wiring for my existing L14-30 cord to my Onan Generator via a new female receptacle without a safety or damage concern to my RV.

I think your original post had TMI. Who cares about the 240V pool service for emergency power!
Look. Your Onan puts out 2, 120V feeds. What I can figure from the specs I looked up is that you have one 30A breaker and one 20A breaker on THE GENERATOR output leads. Your L14-30 female plug is 4 wire// L1,L2,N,G. One of the legs will provide up to 30A of 120V power and the other up to 20A of power but not to exceed 4.5KW total power.
Plug the dang cord from the generator in to the house and run your transfer switch connected stuff. If the 20A breaker on the generator trips move the loads around till you get a good mix. If the 3500 was running things with no problems your 5500 will see the loads as a walk in the park. Just remember, you can't have ANY 240V loads connected to the transfer switch. You could damage them.
Hope this helps to clear the snowstorm of confusion from your thoughts.

Just a word of understanding that fits many of us on this forum. KISS. Keep It Simply Simple when you present a problem and ask a question. We will help you get to the best solution as you try the best suggestions posed by each of us.
I have not seen a topic yet where there would not be a real knowledgeable person who fully understood the problem and had the right answer. God bless you all!
Let us know how things turn out. I think you will be pleased.
Rick Y

[powercat_ras]

I'll throw my two cents into this thread. The answer to your question given your clarifications is yes, but only if you can manually make sure you never run total loads thru the cord of over 30 amps.

To do it right, you need to size the receptacle to be able to handle the full 5,500 watt output of the generator which would involve up to 45 amps flowing thru the neutral part of the plug and receptacle (because the Onan 5500 outputs the same phase on L1 and L2, the current on the neutral is additive, L1 + L2).

To do this, change the plug on your cord to L14-50P and use a L14-50R receptacle. Doing this will de-risk overloading the neutral connection thru the socket and plug and having it overheat and fail when under heavy use.

[DavidM]

Randy:

So you are saying that the Onan doesn't produce separate phases on each power leg, Li and L2. They are all the same phase.

So what would be the problem if the OP draws up to 30 amps on one leg. I don't see one as it should not be unbalanced.

Confession: I thought 50A RVs had separate phases on L1 and L2 but they never used the 220V that would be available across L1 and L2. So, I am learning.

It seems that maybe there is just one L1 from the generator and it feeds a 30A and a 20A breaker, right?

David

[Morich]

I try not to get involved with 3 phase discussions as it is not what I look at enough to bother.
However, this seems to have gotten into lots of confusion ,so I did some searching on this genset and found this:

Cummins Onan QG 5500 RV Gasoline Generator - 5.5HGJAB-6755, 5.5 kW Prime, Single-Phase, 120 Volt, Air-Cooled, EVAP

Another point which may be getting confused on his question is the way his RV is wired as there are two different versions on his year/modle and from previous discussions, I believe he has the one with an automatic tranfer switch.

There are a couple items I would ifrst want to check before saying this is good or not. First I 'feel" it would be okay but that feeling is not strong enough to let me recommend it without asking more questions and those questions are not what I'm prepped to answer!!

Step one is that this is a single phase generator so how does balance enter the question if only one phase? I think of balance problems coming from any one single phase of a three phase setup being way out of line with the other phase?

Moving to what he currently has on his RV power use, the drawing shows he has two 50 amp main breakers in the load center, each feeding one 20 amp sub for each of the two air cond. So if he is only running one AC, is the load on that one breaker going to be way higher than the load on the other breaker and that is IF we choose to be concerned with an "unbalanced" load?

My feeling says running a 30 amp off the switch to the house would be very much like running only one AC in the RV--but that is where I flinch at giving advise on the feeling as going on that vague a thought can get you in trouble!

[powercat_ras]

The OP has a 6 circuit manual transfer switch, that can be wired to 3 120 volt circuits each on a L1 side and a L2 side, this is what the OP has stated in this thread.

Each 3 circuit side is 1: 20 A and 2: 15 A breakered circuits. Each of those 6 circuits has an A-B switch to switch it between being fed from a utility service panel breaker OR being fed from a generator thru an integrated breaker built right into the manual transfer switch box in series with the generator connection.

So since the RV 5500 has two independent outputs, one 30 amp and one 20 amp it may benefit the OP to wire generator L1 to one side and L2 to the other side to maximize the load he can pull. Yes, he could wire both sides from the 30 A L1 and not be able to use the whole 45 amps the RV generator is capable of putting out.

The discussion was how many amps the cable, plugs, and receptacle have to be able to carry WORST CASE. The generator output worst case is the sum of the two generator breakers, 30 + 20 = 50 amps. That is the absolute worst case that can flow back to the generator that the neutral has to safely carry.

The OP will have to wire his 6 circuits to take into account that one 3 circuit group could use more generator power than the other ( 30 vs 20 )

Finally there is the real world situation that Onan uses thermal circuit breakers that can not deliver their namplate rating long term. They can only deliver about 90 % of their nameplate rating continuously for more than about 30 minutes. Anyone who has tried to use their AC and hot water heater in electric mode when both are feed by the same 30 amp breaker on an Onan has experienced this. On this particular generator this "real world" capacity of the breakers actually matches the rated long term output of the generator, 5500 watts.

So the OP should take that into account that the real long term capability of this generator is 27 amps on L1 and 18 amps on L2, not the 30 + 20 shown on the thermal breakers in the Onan.

[dkoldman]

Originally Posted by powercat_ras

I'll throw my two cents into this thread. The answer to your question given your clarifications is yes, but only if you can manually make sure you never run total loads thru the cord of over 30 amps.

To do it right, you need to size the receptacle to be able to handle the full 5,500 watt output of the generator which would involve up to 45 amps flowing thru the neutral part of the plug and receptacle (because the Onan 5500 outputs the same phase on L1 and L2, the current on the neutral is additive, L1 + L2).

To do this, change the plug on your cord to L14-50P and use a L14-50R receptacle. Doing this will de-risk overloading the neutral connection thru the socket and plug and having it overheat and fail when under heavy use.

As a practical matter, I don't think I will exceed the 30 amp 99% of the time, but I have occasionally tripped my 30 amp breaker on my existing genny over the last 10 years. But I fear it could be that one time that cause a problem?

I thought about a 50 amp cord but it only displaces my problem because my home transfer switch is only capable of 30 amps. I have a subpanel that feeds into the switch. I don't think I wish to try to re-wire the subpanel and run heavier wires to the home transfer switch.

[dkoldman]

Originally Posted by Morich

I try not to get involved with 3 phase discussions as it is not what I look at enough to bother.
However, this seems to have gotten into lots of confusion ,so I did some searching on this genset and found this:

Cummins Onan QG 5500 RV Gasoline Generator - 5.5HGJAB-6755, 5.5 kW Prime, Single-Phase, 120 Volt, Air-Cooled, EVAP

Another point which may be getting confused on his question is the way his RV is wired as there are two different versions on his year/modle and from previous discussions, I believe he has the one with an automatic tranfer switch.

Yes I have the Southwire Auto Transfer Switch. I was thinking of tapping into the wiring between the generator and RV Transfer Switch with a junction box, one to RV Transfer Switch and the other to my new L14 - 30R

There are a couple items I would ifrst want to check before saying this is good or not. First I 'feel" it would be okay but that feeling is not strong enough to let me recommend it without asking more questions and those questions are not what I'm prepped to answer!!

Step one is that this is a single phase generator so how does balance enter the question if only one phase? I think of balance problems coming from any one single phase of a three phase setup being way out of line with the other phase?

The out of balance angle really threw me back because no way around if true. It seems like if I could SAFELY just take one leg I will have 30 amps which is all I need.

Moving to what he currently has on his RV power use, the drawing shows he has two 50 amp main breakers in the load center, each feeding one 20 amp sub for each of the two air cond. So if he is only running one AC, is the load on that one breaker going to be way higher than the load on the other breaker and that is IF we choose to be concerned with an "unbalanced" load?

I agree and wonder if Onan was just talking theory without knowing my coach? I get confused because Connecticut Electric had me go through a lot of trouble 10 years ago to ensure I properly balance the 10 circuits in my home transfer switch which I did. But my portable genny only has 1 30 amp breaker. The Onan 5500 has two 30 amp breaker. I think it may be an issue akin to when they tell you to never run the genny without a load. So if you trun and only have load on one side you got a problem? I could theoretically fix it by wiring the home transfer switch to 30 amp breaker NOT supplying the fridge and turning the fridge and/or a 1500 watt heater ion the opposite side to keep the genny in balance?

My feeling says running a 30 amp off the switch to the house would be very much like running only one AC in the RV--but that is where I flinch at giving advise on the feeling as going on that vague a thought can get you in trouble!

You last paragraph is why I posted, I am shocked that running 30 amps off a 5500 is a wiring pandora's box. It has got to be a safe way to wire to a L14-30R.