Changing RV 240 volts to household 240 volts

[camjam Jay]

I recently purchased 2 3500 watt inverter generators with a parallel kit to hook them togerther. The parrallel kit has a 30amp 110 recepticle and a 50 amp RV recepticle. I know RV 240v splits the 240 to 2 110v. My question is can I adapt the RV 240 volts to household 240v to hook my house up to during a hurricane. Thanks

 

[Jayhawk 29]

First off the normal practice for an extra power source for powering your residence is you NEED a transfer switch before you attempt to wire remote current into your home connections. If not then you run the risk of sending your generator power down a line if you are sending it thru your breakers and main power panel. People risk line workers that's working to restore power or a possible downed line somewhere in water and people walking it it . This can happen even with underground cable that powers a community.

So contact a professional before you consider running power to your house. If you wish to have ac for a temporary time, with some lights, just purchase a window unit for your bedroom and run it on a heavy cord, at minimum number 12, which is the yellow extension cords. Then just use extension cords for temporary lamps. You can also run your fridge and freezer from additional cords with that much generator yoo.

 

[Paul B-FRF]

If your gennys don't have a MARKED 240v outlet no.
I'm guessing your 2 inverter pennies are 110v out put only. Alone or parallel you will only get 110v.
Paulb12

 

[OnTheGo]

When you parallel the generators you will get about twice the amps you get with one, but it will still be 110-120 volts.

You won't be using them during the hurricane, you will use them after it passes. That's when the work starts on the power lines so please follow Jayhawk29's advice at #2.

 

[Jayhawk 29]

There are Y adapters made for adapting two 30 amp 120 legs to a 50 amp 240 male twist lock plug that is used in portable arrangements. But you will need the matching ends, sometimes making them up with their correct mating ends. But you still need to deal with the house setup to do this correctly. Since you are on the southwest area of Florida I am sure that most licensed electricians are familiar with the typical needs for running a house off of a generator setup. If it was mine I would go for the propane Generac equipment. Sure its expensive, but when done correctly you can sit inside in the comfort of your home during and after bad weather events. Of course this is if water has not come in from your missing roof.

Generac Power Systems | A total energy solutions company

Since 1959, Generac Power Systems has been committed to building the most reliable, durable, efficient, and environmentally-friendly generators and power equipment.

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[Kevin Cooper]

This is an engineers answer to your question, not an RV owner answer even though I own one.
The answer is MAYBE.
If you can tell me the generator make and model, and also the paralleling kit you have or want to buy. Just be sure that even if it will work, you most likely must get permission from the utility company to connect any generator, engine or Solar, to your dwelling. Also, there must be equipment in place to assure that utility and generator cannot be on at the same time, and that with no utility power, your generator cannot backfeed into the utility.

 

[Jayhawk 29]

This is an engineers answer to your question, not an RV owner answer even though I own one.
The answer is MAYBE. If you can tell me the generator make and model, and also the paralleling kit you have or want to buy. Just be sure that even if it will work, you most likely must get permission to connect any generator, engi engine or Solar, to your dwelling. Also, there must be equipment in place to assure that utility and generator cannot be on at the same time, and that with no utility power, your generator cannot backfeed into the utility.

It sounds like the Predator 3500. Yes most developed communities require a permit and inspection from the county or city building department. Living in a hurricane prone region there are so many ways that people revive temporary power until the utilities are brought back on line.

What is really a repeated problem when people have a gas powered generator as a back up power source, few will run them as a regular practice even once a month ahead of hurricane season or before an impending hurricane to see if they will have temporary power for the essentials. After a hurricane passes, small engine guys work almost 24/7 to get the dormant generators back up and running. This includes chain saws too. Ethanol gas, in particular does harm to small engines if it sits on fuel tanks for long periods of time.

 

[camjam Jay]

Thanks for all the good advice. I have been using generators for after the hurricane passes (and we have had a bunch of them) since Andrew so I am aware of all the safety precautions and do follow them. I have a 9000 watt generator that runs everything but A/C but it is not a inverter so I worry about my electronics.

 

[Jayhawk 29]

Thanks for all the good advice. I have been using generators for after the hurricane passes (and we have had a bunch of them) since Andrew so I am aware of all the safety precautions and do follow them. I have a 9000 watt generator that runs everything but A/C but it is not a inverter so I worry about my electronics.

Well this still does not address some missing links here. One major mystery is still your updated generator brand and its connections pertaining to your described parallel kit. And if you have been running your house with a 9000 watt generator, how have you previously connected it to your home.
And with the 9000 watt generator unless you have a huge place it should run your ac , all dependent again on the outlet cord arrangement for 220 power. So a lot of the information is pertinent to this discussion, when asking the group.

I, too have been providing power during hurricanes and hurricane recovery times is all sorts of ways, in most cases with the open framed generators before switching over to the inverter generators. We have even provided essential power to related homes that failed to prepare. As the saying goes," I feel your pain".

 

[camjam Jay]

Well this still does not address some missing links here. One major mystery is still your updated generator brand and its connections pertaining to your described parallel kit. And if you have been running your house with a 9000 watt generator, how have you previously connected it to your home.
And with the 9000 watt generator unless you have a huge place it should run your ac , all dependent again on the outlet cord arrangement for 220 power. So a lot of the information is pertinent to this discussion, when asking the group.

I, too have been providing power during hurricanes and hurricane recovery times is all sorts of ways, in most cases with the open framed generators before switching over to the inverter generators. We have even provided essential power to related homes that failed to prepare. As the saying goes," I feel your pain".

The inverter generators I have are 2 Wen 3500 with a Wen parallel kit with 1 AC 120v 30amp nema L5-30 R
and 1 120v 50 amp AC nema 14-50R.

 

[poohbear]

You can do the Generater without a transfer switch by using a " lockout kit" that only allows the breaker to the genset plug on your house to be turned on is for the main breaker to be off.
My self we invested in a 22kw whole house genny and auto transfer switch. Worth every penny IMO.

 

[Kevin Cooper]

I recently purchased 2 3500 watt inverter generators with a parallel kit to hook them togerther. The parrallel kit has a 30amp 110 recepticle and a 50 amp RV recepticle. I know RV 240v splits the 240 to 2 110v. My question is can I adapt the RV 240 volts to household 240v to hook my house up to during a hurricane. Thanks

I reread your original question. The answer is, the paralleling kit has a NEMA 14-50 receptacle on it, yes you can. The voltages will be 120/240 volt exactly the same as your house. Sorry I misread it the first time.
Best wishes,

 

[piperinv]

Please make sure you look at the documentation to confirm the NEMA 14-50 is labeled as 240V, not 120V. For two generators to produce 240V with a paralleling kit, the generators need to be set so that the two 120V circuits have a 180-degree phase difference. If you don't have the proper phase difference, the voltage experienced by a 240V device (Like a residential AC unit) would be somewhere between 0 and 240V. Most paralleling kits I have seen DO NOT have the electronics needed to synchronize the AC phases between the two generators. You can still use two generators (Assuming you have the correct interlocks) to power your 120V circuits in your house using the NEMA 14-50 plug, but I would not turn on ANYTHING that is 240V on two generators. You could brownout and ruin 240V equipment. Hope this helps.

 

[Kevin Cooper]

The kit ties the generators together to produce 120/240 volts. It synchronizes the electronic outputs so that the sine waves are all at exactly the same time and direction. If it has a NEMA 14-50 it will work.
There is no 180 degrees out of phase issue.

 

[camjam Jay]

Thanks to all. Great information.

 

[piperinv]

The kit ties the generators together to produce 120/240 volts. It synchronizes the electronic outputs so that the sine waves are all at exactly the same time and direction. If it has a NEMA 14-50 it will work.
There is no 180 degrees out of phase issue.

Kevin, correct me if I am wrong, but to get 240V, you need to have the two 120V AC 180 degrees out of phase. (This is how a center tap transformer works.) This way, the peak of one wave and the trough of another wave give you the 240V potential you are looking for. If the waves are exactly the same, you will not have any potential energy between the power legs and will not provide 240V. But you will have 120V on each leg. If the kits do sync the waveform to be exactly the same (I don't have much experience with them), that makes sense. Then, if you plug a 240V device in, it should do nothing and would not damage the device.

 

[Kevin Cooper]

No, not correct. Take out the center tap and think about the windings and sine wave. Let’s use simple numbers. Let’s assume the secondary of a transformer has one wrap per volt. So, you have 240 wraps around a steel core. Ok? Now you apply primary voltage to its coil. The sine wave is of a magnitude of 340 volts peak and 240 volts RMS. This utilizes the whole coil. So far so good? Now at the wrap at 120 turns, you connect a conductor. With 120 turns, so it has a 170 volt peak voltage and 120 volts RMS.
Now for travel direction. Let’s do a half cycle from L1 to L2. Horizontal line is zero volts and the length of the line is time when plotting a sine wave. From 0 to 1/120th second the wave starts at 0 peaks at 1/240th second and back to 0 at 1/120th second. This happens through the whole coil and creates 240 volts RMS forward. At exactly the same time you get two 120 volts RMS forward sine waves measuring from L1 to N and N to L2. Since it all started with all windings in one direction, then it all flows the same direction.
Now comes electric class. If you hook up an oscilloscope to the system, the problem is that it has one common point connection and cannot show what is really happening. So, if you say that “on an oscilloscope, because of its connections, it looks like the sign waves are 180 degrees out on the screen” then I would agree with the 180 degrees.
As far as above the line and below the line at 120 volts equaling 240 volts, no not correct. +120 volts plus -120 volts= 0 volts.
I know it’s what is taught in school, but the part not explained was “On an oscilloscope”
Best wishes,

 

[Jayhawk 29]

While there are some technical details that comes into play when trying to upgrade from what I assume to be an open frame generator to the two inverter generators, I think some caution should be adhered to when saying without hesitation in this format with what I still consider to be a missing link.

Thanks for all the good advice. I have been using generators for after the hurricane passes (and we have had a bunch of them) since Andrew so I am aware of all the safety precautions and do follow them. I have a 9000 watt generator that runs everything but A/C but it is not a inverter so I worry about my electronics.

A clear statement was made that a 9000 watt generator was operating his house. If the 9000 watt generator would not operate his home, first thing to be known from our standpoint is how was it hooked up to his panel and house to operate everything except the ac.

Next would be that we are adding additional connections and wiring before the generator current makes it to the house thru the parallel for two 3500 inverter generators, which I assume was not the case with the 9000 watt single generator.

Personally I error on the side of caution to going further and saying without hesitation from afar that the setup would be ideal and all the stars will be aligned. I would never load this setup of my entire house on this arrangement. And its just a humble ranch style house.

I have witnessed serious issues and fires in homes after a hurricane from attempting to operate half rigged generators. City and county officials are not happy people if things go wrong and proper connections and operations have not been adhered to.

I also go back to another comment that says it all if someone wants to operate their entire home completely without the community's power source. It appears that ac is the one of the number one item that's wanted in this modification or upgrade to the inverter style generator..

My self we invested in a 22kw whole house genny and auto transfer switch. Worth every penny IMO.

Cheers

 

[craigav]

Perhaps one of these days I will try to explain the 180 degrees aspect and in particular how the L1 and L2 interact with each other and how that is related to 30a and 50a common RV connections. The problem I have most is with trying to explain this in a manner that is both succinct and easy to understand by everyone.

In any case, while it is not impossible to create a 240v circuit with two 120v inverter generators that are computer controlled (as they all are) and that can sync with each other, it is how that sync circuit circuit is designed that makes the difference. The manufacturing options for an inverter generator with a design requirement to be able to tie two of these generators together, could be to sync the two inverter generators in a manner similar to paralleling two 12v batteries (resulting in 12v still but twice the current) or series connecting two 12v batteries (resulting in 24v) although I am not aware of any that series connects the two inverter generators. All of the inverter generator style generators with a kit to tie two inverter generators together that I have seen, "Parallel" when using a parallel kit which results in doubling the available current but maintains the 120v and as such that style circuit and kit would be impossible to provide 240v out of it without a change in the inverter's computer programming that controls and syncs the two inverter generators along with a wiring change to series vs parallel.

If this is very important for you CamjamJay, then I suggest to check the manufacture of the inverter generators you have purchased although, seeing how you already purchased everything, you could just start both generators and with the kit connected, use your electrical voltage meter. Connect one probe to L1 and the other to L2 of the nema14-50 (50a) outlet and then you will know (based on having either 240v or 0 v).

This is similar in concept to having a properly wired 50A RV connection that uses both L1 and L2 (which would measure 240v across L1 to L2) vs using a 30A adapter to a 50A outlet which would measure no voltage between L1 and L2 (but 120v between each and the neutral). ~CA

One other thought and in particular to Camjam, with your setup and desire to have 240v in your house, perhaps to run a 240v furnace blower, you could install a transformer designed for this purpose and you would need it to be wired between the parallel kit and the house. I would have to check but one off of the top of my head that I believe is capable of this would be for example the Victron Autotransformer.

 

[Kevin Cooper]

Well, my opinion is my opinion. I husked Google AI this question. If a generator paralleling kit comes with a NEMA 14-50R. Is it producing 240 volts?
Answer:
Yes, if a generator or paralleling kit includes a NEMA 14-50R outlet, it is designed to produce 240 volts. The "14" in NEMA 14-50 indicates a 240V outlet, and the "50" refers to the maximum amperage capacity of 50 amps. The NEMA 14-50R is a 240V receptacle used with a NEMA 14-50P plug, which are commonly used for high-power applications like electric ranges, RV hookups, and EV charging.
Even without finding this, I stand with my earlier comment! No manufacturer would put that receptacle if it did not produce what it is made for!