2004 Winnebago DP Power Grid & Inverter Power Questions

[Morich]

One of the biggest faults I see in any topic of electrical is that we often read what is posted as "standard" or "recommended" as being what we will actually find! We get so used to telling the story one way that we often forget that "standard" doesn't mean "always' as situations are constantly changing and many times nobody goes back to update history!
We know there is a national electrical code but that doesn't mean a local decision can't be made to change what is done locally! Codes and ordinances are political animals and definitely differ in different places or uses.
I once owned a two story building built as four three room apartments, somewhere about 1910-20 and only using 100 amp 110 service. The service line had been upgraded to 240 triplex but the whole building still worked on 100 amp of power available through a single fuse box having four fuses! When a previous owner added a basement apartment, he simply dropped a line off the fuse box and added breakers in the basement and it still worked.
The old knob and tube must have been nearly humming at times but it rarely blew a fuse!
I left it as wired and finally swapped it but I've often wondered why the housing inspection never blinked when they inspected it for the buyer!

[michael1552]

lost all power to electrical panel with shoreline hooked up . no power to main or 12v side. have been on shoreline power for 2yrs. was reconnecting neutral when power went out totally. is there a reset for inverter

[Morich]

You will have to give more specific info and better descriptions to make this work as there are actually dozens of different setups for different RV and with three different sources of power, shore, coach, and start battery systems, what you are saying is not very likely to be what you mean.
As a start, I would suggest doing a look around at what actually still works and what doesn't and then post what year and model and length of RV as trailers have a far different setup than motorhomes, etc.
The inverter only uses DC to make AC, so it will not keep you from having AC power when plugged in.
At this point we have no way of knowing what equipment you have to even begin to guess at what is wrong.

[imnprsd]

I'm back at it and this time I am in my RV. I have a few more questions I can use your help with to better understand my power grid.

QUESTIONS:

* I know the relay inside my Dimensions Inverter acts like an ATS, and when shore power is present, the inverter automatically turns off and goes in to stand by. Correct?

* L1 then is 120V power from the ATS is either A) Shore Power; or B) Generator Power and goes to two places:

1) The Main Power panel; and 2) to the inverter, where it pass 120V from either shore or generator or inverter on to the Sub-Main Panel. Is this correct?

BIG QUESTION:

* Does the inverter ever provide L2 power or power to any of the loads on Circuit #2?

...I don't think it does. Am I correct?

Note: I get that when I plug my 30A "dog bone" into my 50A power cord I am joining L1 (red wire) to L2 (black wire) and my ATS sees it as one circuit. This is not the case when running on inverter power. I.e., if I am correct, the inverter only powers Circuit #1 inside the coach. What is the right answer?

OBSERVATIONS

* The Intelletec EMS-620 power shedder board can only shed what loads are in the main circuit panel.

* The Sub-Main Panel does receive 50A service, but it is protected by 30A breaker, which means all of the loads in this circuit #1 cannot exceed 30A combined or you will pop the 30A breaker.

* The Basement AC runs on Circuit 1 and Circuit #2. These power Compressor #1 and Compressor #2 respectively.

Next big question: If L1 & L2 returns to one neutral wire, how many amps of inductive load can this line handle?

[imnprsd]

Slight correction: In the Sub-Main Panel it shows L2 as the power source. I meant to say it is L1 that feeds this panel.

However, if I am wrong, please correct my thinking so all of us commoners can get this power grid right!

And thank yo for your help!

=== My New Project ===

I have installed a 8,000 BTU Portable AC in my RV and I love it! For more information go to:

https://www.winnieowners.com/forums/...ad-360836.html

This unit draws 8A (max) and I want it to run on Circuit #2 so my generator is load balanced when I run my new portable AC with my Basement AC #1 Compressor on Circuit #1.

==> As for running the #2 Basement AC Compressor, I don't think I will need to unless I am running on shore power and it's over 100F outside. Then I will be glad to have this extra cooling.

Right now I'm in Rocky Point and it's 85F out and not too humid. I'm only running the portable AC in the front cabin and I am only using the basement AC fans to recirculate the air, and I'm comfortable. ...And when the sun starts to go down I'm down-right cold inside the RV and I turn the Basement fan to low. So I am very hopeful this Portable AC upgrade will be a "homerun" when I head for Las Vegas heat in the 100's next month... on my way to Montana!

==> You can never have too much AC so I think I am well on my way to recommending this upgrade to RVs that are 38' long or longer where you can hide the portable AC in your credenza... if you have one.

WHAT ABOUT THE BASEMENT AC #2 COMPRESSOR?

Turns out, you can turn off the Basement AC #2 compressor by flipping the #2 AC-CB in the Main Panel.

...But you can't turn off the #1 Basement AC-CB because it runs the blower motors (basement AC fans).

So with the #2 AC-CB-Off, I will now start using my Portable AC as my main AC and I will turn down the coach thermostat whenever I want the Basement AC to run on Compressor #1 (only) since most of the time I will have the basement AC Compressor #2 CB turned "off."

Note: The portable AC in the front cabin area is much more efficient vs. the Basement AC running both compressors.

So again, when I'm on generator power I will run just the portable AC on Circuit #2; and the Basement AC#1 Compressor on Circuit #1. ...And I will not run the Basement AC #2 Compressor on generator power.

CAN I NOW BE COOL IN 100F WEATHER?

Answer: I hope so. But it's TBD until I test it out.

On shore power I can run all 3 compressors, which will look something like this:

Portable AC on Circuit #2 (8A) + my Victron 17Adc charger on Circuit #2 (2A) + Basement AC Compressor #2 (10A) = ...For a total of 20A on Circuit #2.

Basement AC #1 on Circuit #1 (14A) ... with my residential refrigerator (1A-4A starting) as needed + Receptacles 2A = 17A - 20A Total on Circuit #1.

So this is why I'm wondering how many amps my Parallax ATS-5070 neutral can return to my generator? ...They say the Onan7500 is rated for 70A Neutral on two-35A wires, under resistive loads (probably). So running 20A on each line should be okay. TBD ...and there should be room for a few more amps of headroom. TBD

More questions: Does the Intelletec EMS-620 power shedder only "kick-in" when on 30A or 20A shore power? ...And does it or does it not operate on generator power?

Note: I'm focusing on power balancing when my generator is running; and I'm not so much concerned about load balancing when on shore power.

...But I will need all my necessary loads working on Circuit #1 so my inverter can power them; so this is why I need to run a separate power wire to the portable AC, to put it on Circuit #2, and because all the wall sockets are wired to Circuit #1 now.

That's all I have to share for now. Later I will post my final conclusions.

[jerichorick]

Originally Posted by imnprsd

I'm back at it and this time I am in my RV. I have a few more questions I can use your help with to better understand my power grid.

QUESTIONS:

* I know the relay inside my Dimensions Inverter acts like an ATS, and when shore power is present, the inverter automatically turns off and goes in to stand by. Correct?(yes and charges the batteries)

* L1 then is 120V power from the ATS is either A) Shore Power; or B) Generator Power and goes to two places:

1) The Main Power panel; and 2) to the inverter, where it pass 120V from either shore or generator or inverter on to the Sub-Main Panel. Is this correct?

BIG QUESTION:

* Does the inverter ever provide L2 power or power to any of the loads on Circuit #2?

...I don't think it does. Am I correct?

Note: I get that when I plug my 30A "dog bone" into my 50A power cord I am joining L1 (red wire) to L2 (black wire) and my ATS sees it as one circuit. This is not the case when running on inverter power. I.e., if I am correct, the inverter only powers Circuit #1 inside the coach. What is the right answer?

OBSERVATIONS

* The Intelletec EMS-620 power shedder board can only shed what loads are in the main circuit panel.

* The Sub-Main Panel does receive 50A service, but it is protected by 30A breaker, which means all of the loads in this circuit #1 cannot exceed 30A combined or you will pop the 30A breaker.

* The Basement AC runs on Circuit 1 and Circuit #2. These power Compressor #1 and Compressor #2 respectively.

Next big question: If L1 & L2 returns to one neutral wire, how many amps of inductive load can this line handle?

I'm thinking you are thinking too much. Do all of your referencing from here:https://www.winnebago.com/Files/File...ire_145021.pdf
Your inverter, a MSW type, provides a poor substitute for your house power. A pure sine wave inverter is much more efficient. Most motors won't run on a modified sign wave inverter or will not run well if they do.
All the inverter feeds, when supplying power, is what is connected to the inverter breaker panel.


With L1 & L2 thinking, again you are digging too deep. If you have a balanced load on L1 & L2 your neutral is 0A in an ideal world. If you are loading at 45A on L1 or L2 your neutral will be the same. If you load 45A on L1 and 10A on L2 your neutral will be 35A. L1 and L2 cancel each other out in the neutral.



I believe your generator puts out 2, in phase, 120V feeds. It is a 3 phase inverter generator. Remember, your generator can only provide as much current as the generator breaker will allow. Your coach may be a 50A rig but you don't have 50A for L1 and L2 on generator.



I hope I have cleared up some of your questions and confusion. KISS. Keep it Simply Simple.

[imnprsd]

UNRAVELLING THE 50A RV POWER GRID

jerichorick: I know this 50A-Service RV Power Grid Stuff sounds very confusing, as I have laid it out, but I'm almost "home" and I think with your help it will clarify a number of things never addressed on a forum... at least not in any posts I have read... so us "commoners" can grasp these principles.

First, I sincerely appreciate your feedback and all the assistance Morich and others have provided me to get to this point. Thank you.

=== ONAN 7500 NOTES ===

Yes... my Onan 7500 uses "Onan inverter technology" to produce two single-phase power lines, L1 & L2, rated for 62.5A according the the Onan 7500 spec sheet.

So I am guessing the Onan 7500W got it's name like this: 62.5A x 120V = 7500W.

In these generators (Onan 7500 and Onan 8000) there are two 35A breakers located on the generator. These CB monitor and limit current on each of the two neutral return line wires.

These two 35A neutral (white) wires are also connected to the Parallax ATS-5070. And heavy duty, 8-pin, old style relays hand the automatic switch between generator power and shore power, with PRIORITY given to the generator.

So if the Onan 7500 spec calls for 62.5A and the neutral wires are each rated for 35A (70A total), that makes sense.

However, I get the impression current is "summed" when it is returned to the Onan 7500 generator. Is this true or not true?

I.e., they make both summing and canceling generators, and I think when Onan says they use inverter technology, they mean they produce AC voltage, then rectify it into DC voltage, and then create two single-phase, PSW outputs.

Other types of generators do not do this, but there are benefits to "inverter-generator-design" I will not go into here. Just take my word these inverter-generators run quieter, but are not as efficient.

=== Shore Power Notes ===

I need to correct what I said in an earlier post(s). I made a mistake. When using shore power your L1 & L2 are out of phase with respect to neutral and are not single phase like your Onan 7500 generator is putting out.

This is why, on shore power, you can measure 120V on each leg-to-neutral; and measure 208V on from L1 to L2.

Note: In your RV your neutral return line is thicker than either L1 or L2. This is because your RV wiring has to handle both generator, shore, and inverter power. And in your RV your ATS is handling the switching between sources.

==> My guess is that it's the neutral contacts on the generator side that get toasty over time.

jerichorick: Are you saying that current is subtracted, when measured on shore power, because of positive and negative phases?

Why? ...I think this is right: Current is subtracted if it's heading in opposite directions caused differences in phase relative to the neutral return wire?

However, can you/anyone confirm that current is summed when running on generator power?

=== Automatic Transfer Switch Notes ===

Modern day ATS boxes are not providing enough terminal connections for the Onan 7500/8000 two neutral wires. Worse, if you twist these two neutral wires together (like some RV techs probably do), so you can use the terminal block they give you in these newer style ATS boxes, then you will most likely burn up your new ATS box even -- though the makers say it is for 50A-Service. It’s not for us Onan 7500/8000 users!

So, let's be clear: 50A-Service does not mean you can run 50A of current on L1 & L2.

Plus these newer ATS boxes marketed for 50A-Service are now using lighter weight, cheaper 40A relays inside.

One more thing: Your ATS relays contacts are can only run about 60% of their rated current handling ability CONTINUOUSLY when the loads are resistive (meaning a floor heater) which is 24A (total) in these newer ATS boxes; and 50% (or 20A total) when running inductive loads, like air conditioners.

==> Next time you open your Main Circuit Panel you will see there is an inductive coil the thick neutral wire passes through. This is the pick-up device that is measuring your current in Amps.

==> And haven't you always wondered why you can only read your current monitor when you are NOT on 50A-service? ...Now you know. Current is subtracted when on shore power, and if they (Winnie and others) allowed you to read your Amp Display on shore power, then you might see anywhere from 0-10A, even with your air conditioners running, and that would confuse you. So they blank the Amp Display out when connected to 50A service.

30A-Service uses a "dog bone" connector so L1 is "bridged" to L2. Therefore, on 30A Shore Power Service you current is in phase and now your Amp Display is giving you the correct output.

On generator service, once again, your L1 & L2 is in phase, and your Amp Display is working. But remember your ATS contacts can only handle as much current as those relays inside are designed to handle and will burnout over time under heavy loads. ...Especially on the neutral wire that is carrying all the current, but fortunately, the Parallax-5070 has relays that will divide the current in half and return it to the generator. Unfortunately, they stopped building the ATS-5070 over 10 years ago.

My point is that you really need to look closely at the ATS you buy if you own an Onan 7500 (62.5A) generator, and especially if you own a Onan 8000 (65.6A) generator.

I think they stopped using these ATS-5070s in ~2012. ...Next week I should have completed a thread on how to rebuild your old ATS-5070. TBD. If I'm successful, this old box will perform better than any ATS on the market designed for 50A-Service, because this old style ATS-5070s use old style, Heavy Duty, 8-pin Relays that are still the best relays for RV use... until you get into "big dog ATS territory" at 100A, which are very costly.

BTW, I called Parallax and one of their engineers told me the old relays were more robust than the new ones.

=== Load Balancing Comments ===

What is load balancing?

I think the goal of "load balancing" was summed-up by jerichorick when he referred to measuring current on the neutral return line, and he called it a "perfect world."

However, I think jerichorigk was referring to shore power load balancing and not to the Onan Inverter-Generator?

However, in a manner of speaking, load balancing still applies to the Onan 7500 too, because current needs a path back to it's source.

Moreover, in a generator, L1 & L2 are derived by rotating magnetic forces between the stator and the rotor. My point being, especially with heavy loads, you want to load current on L2 to be as close to the load current on L1 -- so your generator runs smoother and longer.

So in this particular generator, the current is not out of phase with respect to neutral, but the current still need to be balanced on the rotor and stator. And just to be clear, when you run your generator the single neutral wire out of your Main Circuit Panel is carrying the SUM of L1 & L2 currents... back to the ATS... and then splits the current in half when it returns the current back to the generator (stator/rotor).


QUESTIONS REMAINING

* Does the inverter ever provide L2 power or power to any of the loads on Circuit #2?


==> Note: My Dimensions Inverter outputs a quasi-sine wave (not an MSW) that has been running my residential refrigerator just great for 5 years.

==> However, my Dimensions Inverter should not be used to power a portable AC or a heated blanket that did not come with an old-style rotary dial. (Take my word for it.)

[jerichorick]

Bummer!!! Firefox crashed and I lost all of my writing to you. New approach.
I worked for a few years installing Onan ATS's on portable Onan 60KW generators and many even larger. I have a bit of a handle about these systems inner workings. Let me see if I can break this down to a place where your questions are all answered. I will walk you through the ATS working world.

Your Energy Management System is one of the brain that protect you appliances and prevent breaker tripping . If your demand load needs become greater than the supply power source can provide, the EMS disconnects loads by level of priority. This is determined by the RV manufacturer.

Your sources of power are from the pedestal, generator or inverter. Here we are considering 50A shore power, 7.5K generator and 2KW inverter.

The ATS only functions in response to the shore power or generator power presence.

The inverter has an internal ATS. This passes power from the RV service panel through the inverter breaker to the inverter for battery charging, and from the inverter to supply AC to the loads through the inverter breaker.

The EMS is always on duty.

Shore power: A 3 wire 6AWG cable with a 8AWG ground is the cord we are supplied with. Colors are Red, Black, White and Green. Red & Black are the hot leads, the White is the neutral and Green is ground. The Green keeps the coach chassis at a safe potential to keep us from getting shocks. The White is the same size as the hot wires because it has the potential of carrying 50A. No more. Each hot leg is a 50A source of power when plugged into a 50A shore power source.

Loading: The hot wires are known as L1 and L2. Without great detail, alternating current (AC) is a sine wave or alternating positive to negative voltage/current source. When L1 is going positive, L2 is simultaneously going negative. When they meet in the return Neutral they cancel each other out if at the same values. Thus the term Neutral.

Generator: This is a different type of power. It supplies 2 separate 120V feeds of a rated value determined by the generator specs.

Inverter: AC in, DC out. DC in, AC out.

Let's put it all together. What follows is considering all is normal and functioning for camping.

The coach ATS sees the shore power and passes it on to the service panel 2 50A breakers. These energize the L1 & L2 of the service panel and the associated breakers/loads. The EMS is always monitoring the incoming voltage and load demands. When shore power is disconnected or lost, and the inverter is the source of power, the EMS detects and compensates.

I'll stick with the ATS function.

For the following the generator and inverter need to be set up correctly. The generator must be in Auto Start and the inverter set to Invert and Charge.

When shore power is lost, IE power outage, the ATS drops off and the generator senses the loss of live voltage. It starts. At the same time the inverter senses the loss of line voltage and its internal ATS switches to provide power to the inverter breaker in the coach service panel that is being made by the inverter changing the DC to AC and feeds the associated loads.

When the EMS is satisfied with the quality of the generator power (coming through the ATS), it applies it to the 50A L1 & L2 breakers. But, because the EMS knows this is the generator (a detection circuit notifies it... transformer in the service panel) it sheds any active loads that are too high for the power supplied. The inverter ATS sees the generator voltage and switches back to being a battery charger.

When the shore power returns, the generator continues to run until the demands for A/C or inverter charging are satisfied and the cool down period has ended. The generator stops. At this time the ATS goes back to shore power. The EMS responds nearly instantly to this condition.

Remember, the generator takes priority and the ATS will switch to it when it come online. So, if you have good shore power to the coach and you manually start the generator, the ATS with switch.

On 30A service L1 & L2 are joined and you only have 30A, not 100A, total available. I have the option on my inverter to limit the amount of current it will draw. I adjust it to fit the needs of the supply. I set it to 5A on 30A/20A service and 20A on 50A service.

You might research these: https://smile.amazon.com/Technology-...572761&sr=8-10
https://smile.amazon.com/Parallax-Po...0572761&sr=8-3

I think I covered it all. You can only use as much power as you have available at any one time.

If you are going to use a supplement A/C unit make certain it can run on a MSW invert or that your inverter is a pure sine wave type. A 2K inverter is good for about 16+ amps. For a MSW, inductive loads, not so much or not at all, depending on the device. Be cautious with the standard electric blanket. PSW inverter only unless otherwise stated.

Happy trails,
Rick

[imnprsd]

jerichorick: I appreciate you sharing your credentials and the extra effort you went to in order to post your reply.

Note: I have had similar experiences, losing your draft, because after 1 hour the system will close the thread, but not warn you of this. So now I always "select all" and "copy" my work before I hit the "submit" button. Just in case.

IS LOAD BALANCING A MYTH ==
FOR ONAN 7500/8000 GENERATORS WHICH USES 2 NEUTRAL RETURN WIRES (35A each), AKA 70A Neutral?

With a clearer understanding as to how amp measurements are read on the neutral return line (shore power vs. generator power), I went back to my Main and Sub-Main Power Panels and took some more measurements... confirming every you said. I also found you really have to be sure your clamp meter is tight or you can get an erroneous reading.

To review: When on Onan 7500 (50A, single phase) generator power, the current in the neutral return line is always "summed" together; and when on 50A-service shore power, your neutral return wire will show the difference between L1 & L2. GOT IT. THX.

LOAD BALANCING ASSUMPTIONS & CORRECTIONS

Up until now I have been concerned about the loads on L1 and L2 when running on generator power. However, maybe I did not have to be concerned at all. We shall see.

For example: I was thinking that if L1=26A and L2=0A, that this may not be optimal for the generator.

My assumption was that you should strive to "balance the loads" on L1 & L2 so your generator neutral return L1 & L2 evenly, but maybe this assumption is all wrong? IDK. ...So, I could use your help to explain this new assumption on my part:

* When I look in my Main Panel I see ONLY one thick neutral wire that returns the sum of all load currents back to the ATS-5070.

* ...And so, if all the load currents are being returned on 1 neutral wire, which then connects to 2 neutral wires inside the ATS-5070...

...doesn't that mean half (or 50%) of the total load currents will be evenly returned to the generator?

[B]..And therefore by design, I sounds like it does not matter how you load Circuit #1 and Circuit #2 inside your coach, until you start to exceed 28A or so, because the ATS will divided the current in half. ...Is this correct?[/B]

For example:

Let's say I'm on Onan 7500 generator power.

...and my amp gauge located in my power center is showing 26A total. And my multi-meter is showing:

L1 = 26A
L2 = 0A
And a single neutral return wire to the ATS is clocking-in at 26A.

QUESTION

* Is this 26A split in half by the time it gets back to my Onan 7500 generator? ...And therefore, 13A will be returned to the generator on one of the neutral wires; and 13A ill be returned to the generator on the other neutral wire?

[jerichorick]

Originally Posted by imnprsd

jerichorick: I appreciate you sharing your credentials and the extra effort you went to in order to post your reply.

Note: I have had similar experiences, losing your draft, because after 1 hour the system will close the thread, but not warn you of this. So now I always "select all" and "copy" my work before I hit the "submit" button. Just in case.

IS LOAD BALANCING A MYTH ==
FOR ONAN 7500/8000 GENERATORS WHICH USES 2 NEUTRAL RETURN WIRES (35A each), AKA 70A Neutral? NO. Separate circuits. Like one in the kitchen and one in the living room. You don't add them together. This has to do with the 3 phase inverter in the generator. Pure physical makeup. Do not think of it the same as you do shore power. From the ATS to the service panel is a short run with low loss. Here you can have up to 70A of current when on the generator. But this is not SUSTAINED current. Each load is momentary or short term for the most part.

With a clearer understanding as to how amp measurements are read on the neutral return line (shore power vs. generator power), I went back to my Main and Sub-Main Power Panels and took some more measurements... confirming every you said. I also found you really have to be sure your clamp meter is tight or you can get an erroneous reading.

To review: When on Onan 7500 (50A, single phase) generator power, the current in the neutral return line is always "summed" together; and when on 50A-service shore power, your neutral return wire will show the difference between L1 & L2. GOT IT. THX.

LOAD BALANCING ASSUMPTIONS & CORRECTIONS

Up until now I have been concerned about the loads on L1 and L2 when running on generator power. However, maybe I did not have to be concerned at all. We shall see. If problems in the design were to be, it would have happened many years ago to some earlier RV adventurer.

For example: I was thinking that if L1=26A and L2=0A, that this may not be optimal for the generator. I hope you now see that the generator does not care. Two separate generating sources. The inverter does all the compensation. Lots of physics and math here. Well beyond the simple user and deep into the engineering world of making stuff work.

My assumption was that you should strive to "balance the loads" on L1 & L2 so your generator neutral return L1 & L2 evenly, but maybe this assumption is all wrong? IDK. ...So, I could use your help to explain this new assumption on my part:

* When I look in my Main Panel I see ONLY one thick neutral wire that returns the sum of all load currents back to the ATS-5070.

* ...And so, if all the load currents are being returned on 1 neutral wire, which then connects to 2 neutral wires inside the ATS-5070...

...doesn't that mean half (or 50%) of the total load currents will be evenly returned to the generator? I hope you are clear on this point by now. I suggest you take a course on electricity 101. This will give you a more in depth understanding.

[B]..And therefore by design, I sounds like it does not matter how you load Circuit #1 and Circuit #2 inside your coach, until you start to exceed 28A or so, because the ATS will divided the current in half. ...Is this correct?[/B] NO. The wires and relays are simply electron highways. Paths to be followed.

For example:

Let's say I'm on Onan 7500 generator power.

...and my amp gauge located in my power center is showing 26A total. And my multi-meter is showing:

L1 = 26A
L2 = 0A
And a single neutral return wire to the ATS is clocking-in at 26A.

QUESTION

* Is this 26A split in half by the time it gets back to my Onan 7500 generator? ...And therefore, 13A will be returned to the generator on one of the neutral wires; and 13A ill be returned to the generator on the other neutral wire?

SUM UP: If the L1 of the generator is supplying 15A and L2 is supplying 10A, the service panel to the ATS will return 25A to the ATS on the main neutral and the generator will demand a return of 15A on the L1 neutral and 10A on the L2 neutral. These are two separate circuits between the generator and the ATS. The neutrals are SWITCHED in the ATS. Remember, the main purpose of the ATS is to keep the generator from feeding power back to the pedestal through the power service cord.

[imnprsd]

jerichorick: In your last example, I do follow your L1 & L2, but I'm still fuzzy on the N1 and N2 wire loads since my Onan has two neutral wires.

I.e., how can one 30A neutral wire pass uneven amounts of current back to the N1 and N2 generator wires?

==> Is it because the return current always wants to return it it's source?

Just to be crystal clear, I diagramed an Onan 7500 distributed power example using 30A loads (L1=20A and L2=10A) and a 30A neutral return.

Please let me know which is correct with respect to the neutral lines 1 & 2 leaving the AST back to the Onan 7500 generator? Is it 20A + 10A or 15A + 15A?

And if you can double down on what "load balancing" is all about with respect to my Onan 7500, is it the same for all generators, or is it different because I have 2 neutral wires in my Onan 7500?

Moreover, why do they call it a 70A neutral with 35A on each neutral leg if the current is not divides equally? (15A + 15A as I drew it below.)

...The point being, my Onan has a current spec of 62.5A so Onan 7500 has to separate the L1 & L2 return current to 35A max on each neutral wire, giving the ATS the ability to return 70A to the generator. ...Because the relay contacts can't handle more than 50A... is what I thought.

So what is the purpose of having 2 neutral legs: A) To protect the contacts in the relay; or B) to divide the return current; or C) both?

If current always wants to return to it's source, then I understand. Otherwise, I can't figure out how 1 neutral wire with 30A on it can split up the returns unequally into 20A and 10A as diagramed below.

But I will say, I trust your answer, and when I look at my amp gauge (a cheap outlet plug in that has a needle) I see it jumps more-so when I have unequal loading; and this I would attribute to unequal "load balancing." Proving that load balancing is desirable when it comes to generator power output. Would you agree?

[imnprsd]

Understanding how the neutral return works is most important to me if "load balancing" is not a myth when it comes to running my Onan 7500 inverter- generator.

However, let's not loose sight of the fact I'm currently running 28A-29A on L1, and 10A on L2 with just my ACs running.

So then consider what happens if I want to run my microwave, which will put another 10-12A on L1?

==> This will be a problem if my Onan 7500 has a maximum of 35A on each neutral return line, and no one should run above 28A on one circuit from an ATS contact point of view if you ask me. (Assuming 50A-service using a Parallax ATS-5070, which is more robust than the newer 50A ATS boxes being sold today.)

So, I think no matter what, it make sense to run a separate L2 power line and install a separate L2/Circuit #2 wall outlet for my portable AC to plug into.

==> This will lower my L1 to ~20A, before I run the microwave for a short while; and my L2= ~18A, before I turn on my hot water heater element.

...But I still hope jerichorick helps us all understand the N1 and N2 current numbers in the example laid out above.

[jerichorick]

Originally Posted by imnprsd

Understanding how the neutral return works is most important to me if "load balancing" is not a myth when it comes to running my Onan 7500 inverter- generator.

However, let's not loose sight of the fact I'm currently running 28A-29A on L1, and 10A on L2 with just my ACs running.

So then consider what happens if I want to run my microwave, which will put another 10-12A on L1?

==> This will be a problem if my Onan 7500 has a maximum of 35A on each neutral return line, and no one should run above 28A on one circuit from an ATS contact point of view if you ask me. (Assuming 50A-service using a Parallax ATS-5070, which is more robust than the newer 50A ATS boxes being sold today.)

So, I think no matter what, it make sense to run a separate L2 power line and install a separate L2/Circuit #2 wall outlet for my portable AC to plug into. (No need. Look in the wiring diagram and ID the outlets in your coach with labels of L1 or L2. On generator power your will know which one to plug into. You, at that time, are balancing your loads through what you choose to plug in to which L circuit.)

==> This will lower my L1 to ~20A, before I run the microwave for a short while; and my L2= ~18A, before I turn on my hot water heater element.

...But I still hope jerichorick helps us all understand the N1 and N2 current numbers in the example laid out above.

I want you to become a electron in your thinking. Your only goal in life is, when called into service, to find the path of least resistance in order to do your job.
In the generator you have 2 distinct and separate sources of power. L1/N1 & L2/N2. These are circuit pairs. What happens to L2 must happen to N2 because it is the easiest path for the L2 electrons to follow. N1 is just to much work for this little bugger associated with L2. Thus, two separate and independent circuits coming from one green box.

imnprsd, I applaud your tenacity! I hope things are becoming clearer and more comfortable for you to follow. If you put this much effort into the question "Where will I go when I die?" your life on earth will have a real purpose and you will seek and find the real truth in all things. God bless you and inspire you through The Holy Spirit.
Rick

[imnprsd]

jerichorick: There is much truth and irony in what you say.

As for the answer to the N1 & N2 current example above, I assume you are saying 20A + 10A is the answer?

...Suggesting, there is such a thing as load balancing when it comes to good power management on a generator; and maybe all types of generators. (?)

"Be the electron."

The electron really then has no mind of it's own. It just performs a task when the opportunity presents itself.

I should have said, in a closed circuit, current wants to return to it's source; and your point is that you can get electrocuted if you give the electron a lesser path of resistance.

Ironic how positive charges work, but then that too is all about your prospective... in life too for that matter.

The truth is: My life once had great purpose, but now I'm learning how to be
"retired". And apparently I like opening Pandora's boxes wherever my next RV project takes me, and sharing these experiences on this forum with other people who may benefit.

Sometimes this is very satisfying and other times its very frustrating. Like all relationships tend to be.

And here's something I just realized on this journey: The other day I was searching in my "bolt box" and I realized how happy that made me feel.

So not enough can be said about having a well stocked "bolt box." Literally.

Figuratively, I still need some help time-to-time from people like you. Thank you for sharing your expertise and wisdom with us all!

[jerichorick]

Originally Posted by imnprsd

jerichorick: There is much truth and irony in what you say.

As for the answer to the N1 & N2 current example above, I assume you are saying 20A + 10A is the answer?

...Suggesting, there is such a thing as load balancing when it comes to good power management on a generator; and maybe all types of generators. (?)

"Be the electron."

The electron really then has no mind of it's own. It just performs a task when the opportunity presents itself.

I should have said, in a closed circuit, current wants to return to it's source; and your point is that you can get electrocuted if you give the electron a lesser path of resistance.

Ironic how positive charges work, but then that too is all about your prospective... in life too for that matter.

The truth is: My life once had great purpose, but now I'm learning how to be
"retired". And apparently I like opening Pandora's boxes wherever my next RV project takes me, and sharing these experiences on this forum with other people who may benefit.

Sometimes this is very satisfying and other times its very frustrating. Like all relationships tend to be.

And here's something I just realized on this journey: The other day I was searching in my "bolt box" and I realized how happy that made me feel.

So not enough can be said about having a well stocked "bolt box." Literally.

Figuratively, I still need some help time-to-time from people like you. Thank you for sharing your expertise and wisdom with us all!

When I joined my volunteer ministry, and became involved in doing the work that gives others comfort, I found that my purpose in life became more meaningful than when I worked for a living. Like the little electron, my negative status in life is positively attracted to the path of greater purpose. That my adjacent co-volunteer is "loaded" differently than I am does not diminish or improve my efforts. Your L1/N1 & L2/N2 circuits function, withing design limits, in the same manner.
Make your retirement alive with meaningful purpose. Only you can chose to do that. Without it you become like the defective short circuit. All of your energy is expended for not meaningful purpose or productive gain. You simply burn out.
Happy retirement and happy trails.
Rick