Rialta Reality Check - ROOFTOP A/C

[chrisstratton]

Just got a 1995 Rialta. The NP30 generac generator starts, then shuts down. Possibly a board or sensor is the cause of the generator failure. This is not known as a great generator and I estimate about $1500 to repair, or $3000 to replace. The rooftop a/c is 7100 btu.

Here is the concept:
100ah 48v battery
Litime AllInOne. 3500w
Victron 12-48 dc to dc charger and to Use the line feeding the 12 breaker as a connection from alternator
Leave 12v house battery in place for water pump etc
About 800 pv solar on roof (flexible)

I am looking for ideas and any experience in this​

 

[42OhmsPA]

This is what I would do.

Remove the roof unit and install a mini-split heat pump.
Put rigid panels on the roof, utilizing the space where the A/C was.
Buy a small inverter generator.

 

[Q-Dog]

This is what I would do.

Remove the roof unit and install a mini-split heat pump.
Put rigid panels on the roof, utilizing the space where the A/C was.
Buy a small inverter generator.

The Rialta is a little RV. Not sure where you could mount a mini split.

 

[jberger]

They do make inverter based rooftop air, that's what you want to look for if you are ready to replace it. That would help cut your consumption a fair bit and make the idea of running it off of the battery reasonable.

But since the current AC works and the generator doesn't, I would start with repairing the generator before spending on solar.

How can you estimate a repair without knowing what is wrong?
Those little gensets aren't hard to troubleshoot or repair. I'm not a fan of the generac, but you can probably get it running with a tune up.
Change the oil, clean the carb, new air and fuel filters, double check the start/stop switch (they can get sticky and not allow it to run) and make sure you have brand new, non-ethanol fuel for it. That will probably get it running.

The oil pressure switch is what allows it to keep running when you release the start switch, so you can jumper that out and see if it keeps running, there is a factory diagnostic manual that lists all of the tests and cheap multimeter will perform almost all of the tests.

 

[chrisstratton]

The Rialta is a little RV. Not sure where you could mount a mini split

Yes, I am afraid that a mini-split would sort of ruin the appearance if it could be added, and it would add weight. Weight of the PV's is another concern as rigid panels are very heavy (voice of experience here), and the Rialta owners are very concerned with weight. Still, the idea of just buying a cheap portable/external propane generator is one that I have not ruled out.

 

[chrisstratton]

.. since the current AC works and the generator doesn't, I would start with repairing the generator before spending on solar.

I did try to get at the control panel to bypass the low oil pressure sensor and oil high temp cut out circuit, but couldn't get to it. It is stuck behind something else. While there, I saw someone had been there before me as 4 of the panel cover screws were missing. My assumption was that a lazy tech or DIYer' tried the cut-out bypass and gave up. If I had the generator out on a bench, I could probably test it and part-swap until it ran. A new circuit board is about $500, the two "sensors" are about $150. Labor to remove the generator un-install would be $350, and the same to reinstall. That is not something I can do as I'm living in a condo and am well past Medicare age. That puts the "most likely" cost of fixing the thing at about $1000 labor, and $650 parts, at which point I would have a generator which was discontinued and which nobody appears to be "a fan of". I'm not trying to overkill my response here, but hoping to be wrong in my evaluation and have someone say - take it to "Bob" and he guarantees happiness for only $500.

Re: "inverter based rooftop" presumably to allow either DC power or to improve efficiency - also a consideration, but I understand the new "All-in-ones" Inverters are about 90% efficient, and I would only run it when necessary, turning off the inverter aspect while allowing the PV to charge the LiFePO4.

 

[brainbone]

Victron 12-48 dc to dc charger and to Use the line feeding the 12 breaker as a connection from alternator​

I don't think Victron has a 12v to 48v DC to DC charger yet -- just a DC to DC converter.

I would try to get the generator repaired. Parts for it aren't that expensive and seem to be readily available, Not sure if this is the right part, but this control board should fit an NP30 and is only ~$100:

Amazon.com

Guys that specialize in RV generator service generally charge through the nose, but perhaps you can find someone that services small engines willing to do it on the cheap.

 

[chrisstratton]

I would try to get the generator repaired. Not sure if this is the right part, but this control board should fit an NP30 and is only ~$100:

This is good advice, thank you.

 

[42OhmsPA]

The Rialta is a little RV. Not sure where you could mount a mini split.

I should have looked before posting... Unless it's a rooftop that was bad advice on my part.

 

[JustHank]

@chrisstratton - see if your local community college auto classes would repair it. Or refer you to someone more reasonably priced.

 

[chrisstratton]

@chrisstratton - see if your local community college auto classes would repair it. Or refer you to someone more reasonably priced.

I finally decided to remove the thing - then perhaps get it fixed. It is not an inverter style, so value is less.

 

[brainbone]

I finally decided to remove the thing - then perhaps get it fixed. It is not an inverter style, so value is less.

Just about any running RV generator is worth at least a grand or two. Even non-working ones can fetch relatively high prices.

I opted to replace mine with a small portable inverter generator (MXR4000GT) and crammed it into the existing generator bay -- but I don't recommend doing it unless you're willing to work-around the very real safety and cooling issues and like to tinker with things. I was able to sell the old Onan one for more than the new generator cost even though it was much louder, used more fuel and had pretty dirty power.

 

[0truck0]

I expect generator will be much less to repair than 1500.
Your air cond is small and can run on a 2000 watt inverter generator. Not sure if that would fit into your bay, but those are so small you can carry it around when needed. I had a 9200 btu aircond that ran on a 2200 watt generator easily. Installing a soft-start helped to reduce stresses further.
Many times the simple solution to repair is fuel delivery, could just be a clogged fuel filter or slow fuel. It starts because the bowl is full, but the bowl cannot refill fast enough so it conks out.
We need to know the actual amps your aircond pulls of course, but your battery should be enough to run it over night. The issue will be to recharge the next day. you are on the low end of everything (solar and battery).

 

[chrisstratton]

I expect generator will be much less to repair than 1500.
Your air cond is small and can run on a 2000 watt inverter generator. Not sure if that would fit into your bay, but those are so small you can carry it around when needed. I had a 9200 btu aircond that ran on a 2200 watt generator easily. Installing a soft-start helped to reduce stresses further.
Many times the simple solution to repair is fuel delivery, could just be a clogged fuel filter or slow fuel. It starts because the bowl is full, but the bowl cannot refill fast enough so it conks out.
We need to know the actual amps your aircond pulls of course, but your battery should be enough to run it over night. The issue will be to recharge the next day. you are on the low end of everything (solar and battery).

You might be right about the generator repair. However, I've had two folks look at it and it is an electronic issue, which likely means remove and reinstall - not a trivial or cheap task. Further, that generator is not an inverter genny, so lower quality A/C and I also understand that the routine maintenance is a non-trivial thing. The idea to just have a removable generator is appealing. I'm thinking a dual fuel and run it from propane.

 

[brainbone]

You might be right about the generator repair. However, I've had two folks look at it and it is an electronic issue, which likely means remove and reinstall - not a trivial or cheap task. Further, that generator is not an inverter genny, so lower quality A/C and I also understand that the routine maintenance is a non-trivial thing. The idea to just have a removable generator is appealing. I'm thinking a dual fuel and run it from propane.

Shutting off a short time after starting is often the oil level or pressure sensor, or just too low/high of oil, though if you send the exact model number of that genset plus some photos, it would be easier to look for possible failure points. Many of these things can be serviced without dropping the genset.

You'll be in for mostly the same maintenance in an inverter generator -- regular oil changes, checking/adjusting lifters after a couple hundred hours, keeping the carb clean, etc. Though poorly running inverter generators still produce pretty clean power, so many don't really keep up with the maintenance as they should, until the things die.

 

[Aussieguy]

You could put a small window unit in a cupboard or in a outside storage bin
PLUS add some sort of circulating fan for extra air into the condenser side
would not be hard to figure out how to install

there are also 12v or 24v TRUCK DC a/c that you could put in an enclosed space outside condenser is bolted underneath to chassis

where there is a will ... there's a way!

Newer rooftop with variable compressor are now available around $1,300 :-(

 

[0truck0]

We use an alternating current cleaner on electronic devices at work, tvs mostly so the picture is always perfect. I havent tried it on RV stuff, but for items that are particular about the 120v current there are solutions that might fix the inconsistent current from old generators.

I just bought a cheapo 2 stroke 1200 watt generator. Pluses are that two strokes do not need oil changes (there is no oil, err the oil is premix) and it is very small at 37 lbs and is plenty to help keep batteries topped off; I dont plan or dont think it will do anything other than charge batteries. I run a DC powered air cond so likely the solar will not keep up on some days.
Cons are that it is louder but l mount it on a front hitch which is so far away that sound dosent matter.
These were $99 pre-Bidan, but run about $170 now that four years of inflation set in, still not a bad price. I have a Ryobi inverter 2200gen, but on long trips the oil change is a hassle and it is about double the size of the new one.

 

[brainbone]

I have a Ryobi inverter 2200gen, but on long trips the oil change is a hassle

Fluid extractors make oil changes on small portables a lot easier:

https://www.amazon.com/dp/B0BNMRQDZ2

 

[Aussieguy]

turn the 2200i over and empty the oil out of it

I 'm just to darn old and cranky to deal with a generator
i'll plugin at a camprgound or moochdock if I have to use the a/c

 

[HRTKD]

Since the generator starts and then shuts down, is it possible that your electronics are overloading the generator? Disconnect everything that puts a load on the system, then start the generator.

 

[0truck0]

Fluid extractors make oil changes on small portables a lot easier:

https://www.amazon.com/dp/B0BNMRQDZ2

Thanks, this is good, but is still an Oil Change. I would rather pre-mix the oil then burn the oil than have to do oil change, then deal with the old oil and not to mention that the gen is mounted on a locking hitch gizmo that involves more work. 2-stroke so much easier for my travels.

 

[0truck0]

Since the generator starts and then shuts down, is it possible that your electronics are overloading the generator? Disconnect everything that puts a load on the system, then start the generator.

I bet he tried that. One should never start the gen with a full load, or any load plugged in. Modern gens should remain running and disconnect the 120 feed if overloaded, if his shuts off to overload then he has more issues.
As mentioned, low oil (self shut down of motor) or carb issues are the most common. Take carb bowl off, spray cleaner in, and see if that fixes. If the float in the bowl is stuck or slow then shutdown, if fuel flow way too slow then shutdown, if fuel filter clogged..., so many simple things it could be.

 

[HRTKD]

My hunting partner's Honda 2000i generators will shut down completely on overload.