Generator year.

[Guysakar]

Hi guys,

I originally was going to get a class A mid 30 foot motor home and was basically talked out of it. I am glad I was, as a shorty (low to mid 20's) is more of what I need.

Anyway, my price range is about $15K which is putting me at the year 2000 range.

I have seen some older model motor homes which have a generator which is not very quiet and runs at a constant RPM, regardless of load, which I really, really do not want.

Do you think that that is going to be a problem with 2000 models? One in particular that I am looking at has a 4K watt Onan, but the owner is an elderly couple and doesn't know much about it.

It is several hundred miles away, so....


While I'm at it, what kind of MPG can I expect from a Class C 22-25 footer, with a slide? I gather that the larger ones get around 8 MPG highway. Will the smaller class C get much better?

Thanks for any help.

[davegvg]

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[davegvg]

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[davegvg]

Guysakar wrote:

tatest wrote:
Don't expect to find a more "modern" gasoline RV generator with "Eco" mode and reduced idle speeds. Even Honda's RV generators (as opposed to portable) are constant speed.

There is a reason for this, RV onboard generators are primarily used to power air conditioning, and a "constant" speed generator uses rotational energy to handle the surge of A/C compressor startup, slowing slightly to give the engine time to power up for the load. An inverter genset running reduced idle simply has no energy source to supply that surge of power (which might be 3X to 6X the rated output), which is why Honda tells you not to use Eco for air conditioning.

Some high-end RV/Marine gensets, all diesel that I know of, have inverters, but the inverters are rated for the A/C starting loads, and some are part of a hybrid system that stores electrical energy in a battery bank to provide the surge of power that the engine cannot supply until it spins up.

So you have essentially given yourself a set of rules that say you will not use the on-board genset in a low-cost motorhome.

I disagree. If a Honda EU2000i can start most 8K BTU AC units on Eco mode (and even some 10K units) I highly doubt that a 4K W genset will have trouble starting a 1350 BTU on an eco mode type setting.

What's more, all an RV company has to do is put a hard start capacitor on the AC and it is a near guarantee that it will run the AC in eco mode.



Plus, you can take one of these portable generators and place them on the dining room table during dinner and (other than the carbon dioxide poisoning) not really be bothered by it.

Why can't they put this tech in an RV gen?

I just cannot make since of it. The tech has been there for a quiet, fuel efficient generator for sometime, yet you have to buy the most expensive of rigs to get it?


I'm going to go down to the dealership and listen to gens tomorrow, but I have been listening to them on videos just now and, coming from the Honda EU series, I don't think I am going to be very happy.

My Honda 2000 Generator running an air conditioner is a roaring little beast. So is yours
IF you had one on your living room table it would drive you out of the room in 30 seconds. Powering laptops idled down to a few hundred watts sure - but at full output- go try it.


I put a supco SUPP6 hard start capacitor on the 13.5 AC on my toy hauler and a single honda 2K will start it with eco OFF the second the compressor when to start it instantly killed it capacitor or not.

There are variable RPM gensets but you have to go to a diesel to get it my RVQD 8000 is variable RPM and inverted just like a 2K, but has the rotational mass and torque to kick over a 15K domestic from "idle."

Oddly even with the variable RPM feature it is not really more efficient than my power tech single speed 1800RPM diesel - and both are far quieter when running an ac unit than a one or even two hondas by a large amount.

[ryanallie1]

Hi All.

My second post here on this subject. For the "Price Range", that your going to have you really only have two choices. The "1800 RPM or the "3600 RPM" Our Motorhome has the "3600 RMP Generator" in ours.

Like I said, add a "Ven-Turi System" to your Generator, it does help by quite a bit. Plus it keeps the "Exhaust" up and above your Motorhomes roof line, so you don't get any of your own "Carbon Monixide".

We like the idea of having both types of Generators, a Built-In "3600" RMP.

And then our Twin Sets of Honda EU2000's, and the Parallla Kit and the Extended Run Tank. The Honda's you just can't beat for Boon-Docking at all, not when you can run one of the Honda's for just about a perfect 10 1/2 Hours of run time on 1.1 Gallons of Gas. Connect them both up and your set for the night while Boon-Docking. We have been asked many, many times if we wanted to sell our Honda's. Just no way that will ever happen. Its nice to be able to run just one Honda when we feel like it.

As far as getting the Motorhome Industry, and the Generator Manufactors to build and put in better and quieter gaenerators, its not going to happen until everyone stops buying what they are selling. The same thing with all types of Motorhomes getting better MPH our of their "Gas Tanks".

ourselves, we pretty happy with what we already have.. Did the inside Make-Over, and that turned out nice, and we get pretty fair MPG< not to bad for a Gasser. Really can't complain as we have seen some on here, and how they only get 4-5 MPG. Now we sure wouldn't own one of them, that's for sure.

Live Live and enjoy it the best you can. Good Luck. Dan & Jill & our two small "YORKIE KIDS, who love to travel as much as we do.

[mlts22]

Dutch_12078 wrote:
Customer demand drives what equipment is offered on RV's at what cost. If there was enough demand for so called "eco-mode" generators in RV's they would be offered, at least as an option. For me personally, I find it much more annoying to listen to a generator throttling up from idle every time the load changes than listening to the low rumble of my 7KW Onan's near constant 1800 RPM.

There is also the issue of being able to put the wattage out. If a generator is on Eco-Throttle and a compressor starts up, it won't be able to "spin up" enough to handle the load, thus causing low voltages and shortening the life of the compressor.

What would be interesting to see is a generator made similar to a Yamaha 3000iSEB, except with more "boost" potential. It would be a variable speed model, but with the ability to pull off a set of AGM batteries for a few seconds. That way, a genset running at 800 or so RPM would be able to "catch" the load of a microwave or A/C at full head pressure, while it spins up to a RPM that can handle the electrical load.

I do agree with you about a constant RPM. One can get used to the 1800-3600 RPM of a genset, but the engine spinning up and down can get distracting.

JMHO, the best engineering compromise would be going back to four pole generators. That way, it can run at a relatively low speed of 1800 RPM.

[Dutch_12078]

Customer demand drives what equipment is offered on RV's at what cost. If there was enough demand for so called "eco-mode" generators in RV's they would be offered, at least as an option. For me personally, I find it much more annoying to listen to a generator throttling up from idle every time the load changes than listening to the low rumble of my 7KW Onan's near constant 1800 RPM.

[Guysakar]

Guysakar wrote:

tatest wrote:
Don't expect to find a more "modern" gasoline RV generator with "Eco" mode and reduced idle speeds. Even Honda's RV generators (as opposed to portable) are constant speed.

There is a reason for this, RV onboard generators are primarily used to power air conditioning, and a "constant" speed generator uses rotational energy to handle the surge of A/C compressor startup, slowing slightly to give the engine time to power up for the load. An inverter genset running reduced idle simply has no energy source to supply that surge of power (which might be 3X to 6X the rated output), which is why Honda tells you not to use Eco for air conditioning.

Some high-end RV/Marine gensets, all diesel that I know of, have inverters, but the inverters are rated for the A/C starting loads, and some are part of a hybrid system that stores electrical energy in a battery bank to provide the surge of power that the engine cannot supply until it spins up.

So you have essentially given yourself a set of rules that say you will not use the on-board genset in a low-cost motorhome.

I disagree. If a Honda EU2000i can start most 8K BTU AC units on Eco mode (and even some 10K units) I highly doubt that a 4K W genset will have trouble starting a 1350 BTU on an eco mode type setting.

What's more, all an RV company has to do is put a hard start capacitor on the AC and it is a near guarantee that it will run the AC in eco mode.



Plus, you can take one of these portable generators and place them on the dining room table during dinner and (other than the carbon dioxide poisoning) not really be bothered by it.

Why can't they put this tech in an RV gen?

I just cannot make since of it. The tech has been there for a quiet, fuel efficient generator for sometime, yet you have to buy the most expensive of rigs to get it?


I'm going to go down to the dealership and listen to gens tomorrow, but I have been listening to them on videos just now and, coming from the Honda EU series, I don't think I am going to be very happy.

Anyone have a response to this?

[Guysakar]

tatest wrote:
Don't expect to find a more "modern" gasoline RV generator with "Eco" mode and reduced idle speeds. Even Honda's RV generators (as opposed to portable) are constant speed.

There is a reason for this, RV onboard generators are primarily used to power air conditioning, and a "constant" speed generator uses rotational energy to handle the surge of A/C compressor startup, slowing slightly to give the engine time to power up for the load. An inverter genset running reduced idle simply has no energy source to supply that surge of power (which might be 3X to 6X the rated output), which is why Honda tells you not to use Eco for air conditioning.

Some high-end RV/Marine gensets, all diesel that I know of, have inverters, but the inverters are rated for the A/C starting loads, and some are part of a hybrid system that stores electrical energy in a battery bank to provide the surge of power that the engine cannot supply until it spins up.

So you have essentially given yourself a set of rules that say you will not use the on-board genset in a low-cost motorhome.

I disagree. If a Honda EU2000i can start most 8K BTU AC units on Eco mode (and even some 10K units) I highly doubt that a 4K W genset will have trouble starting a 1350 BTU on an eco mode type setting.

What's more, all an RV company has to do is put a hard start capacitor on the AC and it is a near guarantee that it will run the AC in eco mode.



Plus, you can take one of these portable generators and place them on the dining room table during dinner and (other than the carbon dioxide poisoning) not really be bothered by it.

Why can't they put this tech in an RV gen?

I just cannot make since of it. The tech has been there for a quiet, fuel efficient generator for sometime, yet you have to buy the most expensive of rigs to get it?


I'm going to go down to the dealership and listen to gens tomorrow, but I have been listening to them on videos just now and, coming from the Honda EU series, I don't think I am going to be very happy.

[frankdamp]

You need to be careful with an Onan on a unit of that age. They didn't switch from carburetors to EFI until about 2005. If the unit hasn't been cycled under load regularly during the off-season, you could have significant problems.

My '02 rig has an Onan 5.5 Kva generator, which is probably an '01 build at Onan. It only had 49 hours on the Hobbs meter when we bought it and it started instantaneously and ran just fine. In our second winter season, I needed cardiac surgery, and my downtime meant that I didn't get out the the rig to do the regular exercising for about 12 weeks. That was in early spring 2012, and the generator hasn't run since.

I suspect the carburetor is toast. I'll replace it, and if still doesn't run, it's time for professional help. It's a nuisance, because we're FHU campers. The only time we needed the generator was to run the second a/c on a very hot day in eastern Washington. Unfortunately trying to sell the rig with a non-functional generator will be a struggle.

[tatest]

Don't expect to find a more "modern" gasoline RV generator with "Eco" mode and reduced idle speeds. Even Honda's RV generators (as opposed to portable) are constant speed.

There is a reason for this, RV onboard generators are primarily used to power air conditioning, and a "constant" speed generator uses rotational energy to handle the surge of A/C compressor startup, slowing slightly to give the engine time to power up for the load. An inverter genset running reduced idle simply has no energy source to supply that surge of power (which might be 3X to 6X the rated output), which is why Honda tells you not to use Eco for air conditioning.

Some high-end RV/Marine gensets, all diesel that I know of, have inverters, but the inverters are rated for the A/C starting loads, and some are part of a hybrid system that stores electrical energy in a battery bank to provide the surge of power that the engine cannot supply until it spins up.

So you have essentially given yourself a set of rules that say you will not use the on-board genset in a low-cost motorhome.

[mlts22]

Guysakar wrote:


OK, that is what I was looking for. I am familiar with the Honda EU2000i, which reduces the RPM's under light load, etc...

You are saying that most motor home generators just run at a constant RPM regardless of load?

So what does that do for fuel consumption? I assume that motor home generators are nowhere comparable to portable generators, then.

I wonder why they can't use the same tech that is in the portable ones in a motor home.

So on a 4K watt Onan, you think 1/2 gallon an hour?

It might be more cost effective to just buy a portable gen and never even mess with the onboard gen, if doing a lot of dry camping.

A Honda 3000 (peak) 2800 (constant) watt gets .17 gallons an hour at 1/4 load and .47 at max load.

Unloaded, 0.3 gallons per hour. Half-load, 0.5 gallons an hour, full tilt, 0.7 gallons an hour. Source here.

As for inverter technology, most everyone on RV.net would agree with you. It would require some engineering though, because with most portable generators, you flip them off of Eco-Throttle (or a similar setting) before firing up the A/C or else the generator may not "catch" the load and spin up in time. Of course, this can be handled by a circuit similar to the Yamaha 3000iSEB and using the battery for a quick added wattage to handle the incoming locked rotor amps from a compressor (or on a lesser basis, a magnetron.) However, for a lot of things, the onboard Onan genset is "good enough". Since gasoline models tend to use the onboard fuel tank, they tend to have plenty of run time, which means it is a lot more convenient to just push a button inside the coach to get the generator running than to go outside in the cold, get out the gas container, manually start the generator or generator pairs, then head back inside to dry off, thaw out, or get cool.

Another use for the inboard genset is using it with a controller from Onan or Magnum Energy. You can then configure it to fire up the generator when the batteries get below a certain voltage, run for a few hours, then stop. You can also configure quiet hours so the generator will not fire up (unless manually actuated.)

My next rig, I'm doing the best of both worlds. The inboard genset will be what I use normally. However, I plan to take along a 2000 watt Honda which is more efficient at gas when boondocking. This provides not just better charging and allows use of all electrical items but the A/C (not all at once), but if the house batteries go flat, the Onan may not start, so it would provide a way to get the battery bank charged enough to allow the onboard genset to take over.

[ryanallie1]

Hi All.

One way to help quite down a Built-ion Generator, is to use a Ven-Turi System on your Generator. They will quite it down by quite, and also carry the Carbon Monixide over and above the Motorhomes roof line on most Motorhomes.

Our Motorhome runs at 36000 rpm no matter what the load is. Its just the name orf the beast. But that Ven-turi Systems makes so we hardly hear it inside our Motorhome when it running.

Of coarse, if I want quitter, I can use our "Twin Hondas, EU2000i's", "Paralla Kit" with the "Extended Run Tank", then it will adjust to the load put on it. Our Hondas, we don't even notice them while running while we are in the Motorhome.

Good Luck. Happy Travels, Dan & Jill & our two "Yorkie Kids" who love to Travel as much as we do.

[SCVJeff]

The quick answer on the generator is that NONE of the installed gas models of any year vary RPM, nor have inverters as one needs the other to work.

[crickeydog]

Guysakar wrote:

Hi, thanks for your reply. I wasn't talking about the state of the generator, but how the generator was designed.

Some of the older motor home generators ran at a constant rpm and did not cycle down when load was low, resulting in poor fuel consumption.

And some of the older ones are much louder than the newer ones.

As I said, everything including how quiet the generator operates will all be directly related back to how the unit has been maintained over the years. To my knowledge, no Onan built in generator runs at variable RPM's based on demand. I know our Onan 6500 watt generator in our 5'er runs at a constant 3600 RPM's regardless of the load.

Happy camping!!! See y'all down the road!!!:)