No AC Power, Dead Inverter? Need Diagnosis Help & Recommendations

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Henry J Fate

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Sure there is a right way, the way I do it, of course! :)

That is to have many inverters. Use small inverters for small loads. Medium inverters for medium loads. Large inverters for large loads.

Small inverters are cheap, even the pure sinewave small inverters.

-Don- Reno, NV

A couple of years ago I had no sensible inverter system and was in the process of designing one. Being not thrilled about all the complexity of installing a large central system, I spent a few days drawing up schematics and parts lists to have local inverters at various outlets switched by a relay which detected the presence of 120 volts and changing the outlet from the inverter to the 120 volt source. I never got to complete that but still have the paperwork for future use. I wound up finding 10 feet of #2 wire at a goodwill for $2.99 and wired my 750 watt inverter into the cabin which I still use today.

The big advantage having local inversion is the ease of wiring. You do not need large wire for a tv/cd outlet inverter.

I like your thinking Don. I still plan to install a few of my designed inverter circuits. One at the tv outlet will be the first.
 
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Mark_K5LXP

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I thought it was my way or the highway?

I guess if one is so motivated, one can circumflatulate with all manner of intermediate storage and power solutions scattered about the coach. My RV came with the inverter to power the TV and my approach to it is if whatever I have won't run on that, I can run the genset or do without. But that's a specific case, mine being casual use and not full time or extended travel in which case even I might sing a different tune. Hence the notion of reviewing the requirement vs nice to have and incorporating solutions from there. DonTom I think you might agree that anything not powered by an anderson powerpole is an unnecessary extravagance.

Mark B.
Albuquerque, NM
 

SunFun

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And you will also need a high power lith converter. At least 80 amps. And perhaps thicker wires. 600 AHs of lith will cost you several thousand bucks, add about another thousand bucks to get to 800AH in lith.

...

-Don- Reno, NV

Right, I currently have up to $3k budgeted, and how big of a system might depend a little on experience. Not a large RV, but I want a lot of power for

I'd probably start with 600AH for around $2k (batteries only), and another $500(?) in misc hardware.

Battery Options:

Charger/Converter $280: https://www.amazon.com/Progressive-Dynamics-PD9180ALV-Lithium-Center/dp/B07DP4KWG3 (reviews are kinda "meh", so I'll probably shop around a little more)

Would I also want to swap the 30A input for 50A, or does that matter? I guess that only affects how fast batteries charge from shore-power. Would that require swapping the entire fuse-box (definitely want an electrician for that job)?

Do I also want "lithium charge controller(s)"? I know they're needed for solar. Would I need them for the generator?

(Apologies, I'm slightly drifting into areas I haven't read/searched as much about, I was planning on doing this about 1-month from now).

Currently, I have up to $3k budgeted here, though no sense in spending more than I need.

Sure there is a right way, the way I do it, of course! :)

That is to have many inverters. Use small inverters for small loads. Medium inverters for medium loads. Large inverters for large loads.

Small inverters are cheap, even the pure sinewave small inverters.

-Don- Reno, NV
That's exactly what I was thinking. Small ones are cheap. Plus you have redundancy & one of them blowing-out doesn't impact the rest of your system.

I was even thinking of having a small one, for a laptop, small devices, or 1-TV for passengers, that runs off the alternator-power, for when I'm driving.

What kind of devices would I want a "pure sinewave inverter" for? Would a computer & LVD monitor/tv need one?

I thought it was my way or the highway?

...

Mark B.
Albuquerque, NM
You sound like a software engineer, or project manager, hah.
 

SunFun

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You can't run Air Conditioning on an inverter. It's a heavy inductive load, it will deplete your batteries in less than an hour if it works at all and it is prone to blowing the power transistors right out of the inverter (I repair inverters). :)

If you want AC you need shore power or you need to run a generator.

If you can live without a microwave you can make do with a small inverter, (500W?) to run your computers and/or TV. If you want to run your microwave without starting your generator you will need about a 2000W inverter.

There is savings to be had with a large inverter because larger inverters have integrated transfer switches AND they can also include heavy duty three-level chargers. You want this! a 2000W inverter with a 75A charger will bulk charge your batteries to 80% in a couple of hours. This keeps your generator run time low. You get everything you need in one box and that simplifies wiring and reduces installation costs.
Alright, seems I may just boot up the generator each time I need to run the A.C., or use the truck-AC, which is probably fine. Unless the AC is "smooth start" (I doubt mine is), I believe they tend to create a massive spike on startup.
You stated the RV already has a 5KW generator. It produces 5000 watts of 120v power and all your 120vac stuff will run fine off it - doesn't need to be an "inverter generator" to do that. There are some advantages to an inverter-generator, but the output power is the same with a non-inverter type. One of the things the generator powers is that 9140 converter, so your batteries get recharged while the generator runs.

Your laptop probably has a 12v power module available so you could plug it to a 12v outlet for charging rather than 120v, but an small & inexpensive portable inverter will also handle it nicely. A simple model like the one below would do the job for laptop and phone charging. You would need to add a 12v outlet capable of delivering 30-35 amps to supply power to the inverter.

For some reason I thought generators by default were DC, but I think my ignorance is showing.
Good thinking about the laptop; by default the power-adapter converts AC to DC for laptops. It looks like there are also 12v-DC desktop power supply's: High reliability 12V Input PC ATX computer DC-DC Power Supplies, 12VDC Input, autonomous vehicle computer power. car computer power supply, 12 volt, 320W, 450W, 500W, 650W, 1000W, ATX DC-DC (not sure I'd buy these specific ones, but just noticing they exist).

I snagged a 1kw Bestek for my desktop computer. I'll probably get a 300 to 500w for the driver area. Perhaps another 300-500w for the bedroom.
JayArr is correct but there is an efficiency penalty for running small loads with a large inverter. The large inverter is a must have for the microwave but is swatting flies with a hammer running lesser loads. Maybe not a huge consideration if replenishing with genset power but if boondocking with solar, you're peeing away a percentage of that fleeting power. No right or wrong way to do this, but there is a sweet spot that makes taking cost, value and capability into consideration.

Mark B.
Albuquerque, NM
I don't need the microwave. I can easily heat things up on the stove, or pull out my propane flame-thrower. It would be nice, but not required, to be able to use a 1500w appliance like a water-heater from time-to-time.
 

DonTom

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Would I also want to swap the 30A input for 50A, or does that matter? I guess that only affects how fast batteries charge from shore-power.
For the amount of batteries you want, even 50 amp will be slow, after they are discharged, but that discharge will take a long time as well, on the usual loads. But you should use a lith converter as they will charge your battery to 100% as lith is about a volt higher than LA. But you also want to be able to charge from the genny without having to run the thing for days, so go with an 80 amp lith converter at the min.

The solar controller is only for solar. The converter is all you need to charge the batteries from shore or from the genny.

I highly recommend to use a SmartShunt to see how well your batteries are charged instead of having to guess.

-Don- Reno, NV
 

Mark_K5LXP

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Ahem...HARDware engineer.

When faced with the prospect of "updating" my RV to accommodate a kilowatt coffee maker I found it a lot simpler and direct to heat water on the propane stove that's already there. I'm all for redundant systems and operational overlap but the last thing I wanted in my RV was a spiderweb of cabling and equipment with specific applications, or having to rewire the whole thing to accommodate "what if" power scenarios. So I tend to revert to lowest common denominator, 12V. My laptop needs a 19V power supply that runs on AC but there are mobile supplies that have 12V automotive inputs. Some of my network devices want 5VDC so I cut up some power and USB cables and run them from USB power ports. Technically the laptop and 5VDC devices are still running from SMPS's but it's using power outlets already in the RV and by doing so reduces the supply count by one per device. In one place and I'm contemplating a 2nd, I installed a new duplex outlet that's solely fed by the inverter, retaining the OEM outlet functions and configuration to minimize "frankenstein" wiring and control setups that depart from what's expected to be there. No cuts 'n' jumps to the factory wiring, just an addendum with what I've added. It's absolutely OK to just install an inverter, plug in all your stuff and off you go, but with a bit of thought one can come up with ways that are a bit more simple and efficient. Even if power is "free", sometimes you may want or need just that little bit more time on battery, or that much less genset time. If you do a load analysis I think you'll find you can get by with less than what you might anticipate being plugged into shore power all the time. Most loads in an RV are not particularly big nor high duty cycle. Even on extended boondock trips I can easily make it 3 days on a pair of GC-2's running as much as I want whenever. I get the "worst case" idea but would plant the seed that for "worst case" you run the genset, and size your battery bank to "typical".

Mark B.
Albuquerque, NM
 

DonTom

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For some reason I thought generators by default were DC, but I think my ignorance is showing.
Your genny output is 120 VAC much like a real home (that's not on wheels). The converter takes that 120 VAC and provides you >12 Volts DC (even if without a battery, but it charges that too).

The inverter does the opposite, takes the battery and gives you 120 VAC. No need for an inverter when you're using shore power or the genny--it's only for when not using the genny and having no shore power, but it won't run nearly as much stuff for as long as your genny will. But the genny is used to recharge your battery via your converter.

-Don- Reno, NV
 

Rob&Deryl

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To the OP. You mentioned swapping your shore power from 30 to 50a because you think it will charge your batteries quicker.
No! The converter (think battery charger) only puts out so much. For example, mine maxes at 55a @13v. The amount it actually puts out is dependent on the battery and what rate of charge it will accept. Note that you need to think somewhat about power which is (volts x amps). So, 50a @ 12v is 600w. To make that 12v power it draws 600 + loss watts from the 120v circuit which is only 5a. So, since you only need 5a of 120v to get 50a @ 12v, changing the shore power capacity will have no effect.
 

JayArr

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I don't need the microwave. I can easily heat things up on the stove.

Then you don't really need a big inverter. Instead of spending 3K on a bunch of stuff you don't need buy a few 500W inverters for $50 each on amazon and a Progressive Dynamics PD9200 80A three level charger and call it a day.


You already have a generator, solar panels at this point are redundant. They aren't going to give you anything that the genny won't give. With the genny running the PD9200 converter will charge your batteries to 90% in a couple of hours. The solar panels are a fraction of that. Even if you get 1000W of solar onto your roof that's still only 20% of the genny. I think splurging out for solar panels on a RV that already has a functioning charging system is money better spent elsewhere.

How are the tires? Do the AC units blow cold air? When was the last time the brakes were serviced? Does the fridge stay cold?
 

Kirk

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I would agree with others that I have absolutely no doubt that your generator will supply the air conditioner and all other 120v loads when running and no RV inverter would. The generator may have an automatic transfer device that will automatically shift loads to the generator when it starts, and you can tell by starting it when not connected to shore power and try operating the 120V things like the air conditioner and microwave, probably the TV, and possibly a few other things. Most of the appliances like the furnace, lights, water heater, and water pump operate from 12V power all of the time. If you have a typical RV type refrigerator it must have 12v power to operate and also either propane or 120V power. Some motorhomes used to have a place where the 120V power cord was stored that you plug into for storage and that connected to the generator. If yours does have an automatic transfer from shore power cord to generator, it is very important not to start the generator when connected to 120V shore power with any heavy loads in operation.

We could probably give you far better answers if you would tell us what year, make, and model the RV that you have is. I am going to guess that it is a motorhome of some type, as onboard generators are most common on them but there are travel trailers and fifth wheels that have one so that is only a guess.
 

Edd505

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It's an overkill for sure, but it will use a lot less gas with a small load than it will with a larger load, so it's just not that big of a deal. Genny's need to be exercised a bit, especially in the rainy winter time. The parts inside need to be dried out every few weeks or so. Best to use a heavier load, however. I use a 120 VAC heater and run the genny for about 30 minutes or so.

The most use my genny gets is such exercise. It is rarely used, except when I boondock for a few weeks straight at Organ Pipe Cactus Nat'l Monument,. Usually every year around December.

It's best to NOT use the genny when cold to heat a meal for a minute or so. That's one of the reasons I did this in message number 59 there.

-Don- Reno, NV
Not to hijack this but everything on the Organ Pipe Cactus Nat'l Monument say only smaller Rv's. Your avitar picture looks like your too big or the monument. Whats the largest you can get in there?
 

CharlesinGA

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Without reading thru all of the posts, I will COMPLIMENT the OP (SunFun) for their completeness in asking the question and providing all of the needed pics and information in the FIRST POST, and avoiding the "twenty questions game" that many leave the readers to ask due to lack of information.

Feel FREE to ask away about anything, someone will try to answer.

Charles
 

DonTom

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Not to hijack this but everything on the Organ Pipe Cactus Nat'l Monument say only smaller Rv's.
I never thought 45 feet is small. They have different areas for different size RVs there, and up to 45 feet.

See here.

"The campground has 208 sites, four are large enough to accommodate RVs up to 45 feet in length."

-Don- Reno, NV
 
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SunFun

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But you also want to be able to charge from the genny without having to run the thing for days, so go with an 80 amp lith converter at the min.

I highly recommend to use a SmartShunt to see how well your batteries are charged instead of having to guess.

-Don- Reno, NV
Cool, I don't mind the cost of the 80amp converter.

I added the smart-shunt to my notes. It would be very useful to know when batteries are fully charged, no matter what I'm using as a power-source, or about how long I have until the batteries are empty.
Ahem...HARDware engineer.

..... I get the "worst case" idea but would plant the seed that for "worst case" you run the genset, and size your battery bank to "typical".

Mark B.
Albuquerque, NM
My brother is a hardware engineer.

Yeah, stovetop water is probably the most practical. I guess there's nothing 1.5kw that I really need to run when not on shore-power.

My desktop computer is probably the biggest area, where I could benefit from some efficiency. It has a 750w power supply, though not sure actual wattage used. Regardless, DC to AC to DC is an inefficiency.

I don't know precisely how long something like 200AH would last, but perhaps I start with one 200AH to 300AH, and see how that does, before adding another.

Your genny output is 120 VAC ...

-Don- Reno, NV
Thanks, that was helpful!
...So, since you only need 5a of 120v to get 50a @ 12v, changing the shore power capacity will have no effect.
Also, very helpful! Thanks!
Then you don't really need a big inverter. Instead of spending 3K....

You already have a generator, solar panels at this point are redundant.

How are the tires? Do the AC units blow cold air? When was the last time the brakes were serviced? Does the fridge stay cold?
Hah, good points.

The solar idea is really a 20th priority kind of thing. And yes, I need to figure out why my fridge doesn't get that cold off of propane.

...The generator may have an automatic transfer device that will automatically shift loads to the generator when it starts, and you can tell by starting it when not connected to shore power and try operating the 120V things...
Thanks, I'll give that a try.
If you have a typical RV type refrigerator it must have 12v power to operate and also either propane
My refrigerator is definitely gas and 12v. Though it doesn't seem to get that cold off of gas, so I need to go through the manual, and potentially get it serviced or recharged.
If yours does have an automatic transfer from shore power cord to generator, it is very important not to start the generator when connected to 120V shore power with any heavy loads in operation.
I appreciate the warning.
We could probably give you far better answers if you would tell us what year, make, and model the RV that you have is. I am going to guess that it is a motorhome of some type, as onboard generators are most common on them but there are travel trailers and fifth wheels that have one so that is only a guess.
2006 Forest River Sunseeker, 31ft. I don't know the exact model number. Not sure the generator model, I'll have to grab that next time I'm at the RV.
Without reading thru all of the posts, I will COMPLIMENT the OP (SunFun) for their completeness in asking the question and providing all of the needed pics and information in the FIRST POST, and avoiding the "twenty questions game" that many leave the readers to ask due to lack of information.

Feel FREE to ask away about anything, someone will try to answer.

Charles
Thanks, I do try to be efficient.
10KW ( Continuous )not enough? Just need a lot of battery.

-Don- Reno, NV
Did someone accuse full-timers of being practical? Herrasy!
 

DonTom

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I found it a lot simpler and direct to heat water on the propane stove that's already there.
Doesn't that require you to use instant coffee?

I like to grid my own coffee beans and make my Italian Roast coffee every morning, RV or not.

And I did that last year boondocked without a working genny.

73, -Don- AA6GA/7 Reno, NV
 

JayArr

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Stove top boils water for a French Press pretty well. That's what I use. You could always go for an old style perculator/camping pot but they are a bit messy to clean. The last option is an Italian espresso pot which is delicious and boils right on the stove but makes really strong coffee.
 

Mark_K5LXP

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Doesn't that require you to use instant coffee?
In this case, percolator. I don't drink the horrid stuff, I make it for DW. I was presented with the "ultimatum" that if we can't run the genset at 06:00 or whatever so she can make coffee with a Keurig I needed to come up with a solution. One option of course would be a kilowatt inverter installation but that seems like such a long way around the block to make hot water. Got a small percolator and experimented with brew variables on the stove until it was deemed "very good" by her. I consider this task a fair exchange for not having to add a project to the RV to do list. I am contemplating a small (~300W) dedicated inverter for the kitchen to run a crock pot though, having one simmering dinner while underway is having some appeal.

Mark B.
Albuquerque, NM
 

Old_Crow

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I used to have this thing called a Melitta. It was basically a funnel that held a filter and the ground coffee. You put it over a pot(I used one from an old Mr Coffee)and poured boiling water through the grounds. Only problem was, you had to find their specific filters because the round Mr. C. filters wouldn't fit in the funnel.
 
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