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 > Generator to run three RV's?

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Gdetrailer

PA

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Posted: 11/20/21 08:30am Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

Having done lots of power measurements during outages at my house, I found I could run all the important circuits from a 2800 watt kipor generator.

We tend to think of maximum loads--but really I could do fridge, freezer, furnace, most of the lights, router (for wobbly wide web) computers, laptop, garage door openner and block heater for the car. I used a manual transfer switch with six circuits. the Kipor did not overload even once.


RV is not exactly a sticks and bricks..

13.5K AC 13A (1560W) run
RV fridge heater approx 300W
electric heating element in water heater 1200W
converter charging batteries up to 1200W at full load (supporting battery charging duties plus 12V appliances and lighting)
Entertainment, 200W for average LED backlit TV of 32"+ size
And so on..

A potential of 4150W.. Granted not all of those devices will be on or running full tilt, but the potential is high that with three campers attached to one 6Kw gen that at least two campers will be drawing enough other loads that the third camper will lead to enough load to shut down the party..

Pooling generator resources isn't going to save money on fuel either, the smaller gens can be more fuel efficient than a big whopping gen when being under light loads.

I have a 8500W gen with a 13HP engine for my sticks and bricks, it definitely uses more than twice the fuel of my 4Kw gen for my RV with a 6.5HP engine under light or no loads. That bigger engine is very thirsty but I needed that 8500W gen to support my sticks and bricks 220V water well plus a few other 220V items. Otherwise I would have used my 4Kw gen but it is 120V only output and 4Kw would just barely be enough to fire up the water well pump (it is 3/4HP pump in 320ft deep well so the surge is pretty high).

Something else to consider, the bigger gen you go, the much louder it will be, somewhere I have a link to a video I took with a sound meter for my 8500W 13HP gen, very, very loud.. I use good quality hearing protection when I am near it when running.

Weight is another consideration, I used a tractor with front loader to pickup and move my 8500W gen, it weights 230 lbs without fuel, add in 6.5gallons of fuel and now it weights 280 lbs.. Needless to say, mine stays exactly where I planted it.. Moving it even on wheels would not be much fun.

The OPs solution really is for each RV owner to bring their own gen, put them on 50ft extensions in different directions to keep them remote from the campsite for more comfortable sound levels.

pianotuna

Regina, SK, Canada

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Posted: 11/20/21 09:51am Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:

pianotuna wrote:

Having done lots of power measurements during outages at my house, I found I could run all the important circuits from a 2800 watt kipor generator.

We tend to think of maximum loads--but really I could do fridge, freezer, furnace, most of the lights, router (for wobbly wide web) computers, laptop, garage door openner and block heater for the car. I used a manual transfer switch with six circuits. the Kipor did not overload even once.
13.5K AC 13A (1560W) run
RV fridge heater approx 300W
electric heating element in water heater 1200W
converter charging batteries up to 1200W at full load (supporting battery charging duties plus 12V appliances and lighting)
Entertainment, 200W for average LED backlit TV of 32"+ size

A potential of 4150W



air conditioner 1200 to 1900 depending on the length of run

fridge 325 but runs on propane when not on shore power

water heater--1400 watts not 1200. Propane when boondocking, I heat mine as I drive down the road on solar/alternator twenty minutes on, 40 minutes off.

converter 700 watts, but again the solar keeps the battery bank charged.

microwave 1567 watts

Induction cooker 1500 watts (on max)

no television, but I do use a laptop--100 watts

coffee maker 400 watts

lighting is all led--maybe 20 watts if I have all of them on.

2 cell phones at 10 watts each. Charge time about 90 minutes.

So my peak load would be 7932 watts.

But not all devices are on at 100% duty cycle. The one exception might be the roof air.

water heater 90 minutes per day (I let it coast after it is warmed up)

coffee maker 7 minutes per day.

microwave maybe 5 minutes per day?

Induction cooker 30 minutes per day?

I've never overloaded my yahama 3000sieb, except when deliberately trying to do so. To be fair, I do have a load support inverter/charger. The generator does have remote electric start and I use it sparingly.

I do use a watt meter--and on shore power I've never used more than 7200 watts peak load (how--I have 2 auxiliary shore power cords). Average load at -30 is about 4300 watts (per hour so 4.3 kwh). But we are talking summer time, and the living is easy.

My rv behaves as if it were on shore power full time.

I deliberately limit my 30 amp consumption to 23 amps, which is what the Yamaha outputs.

23 x 120 = 2760 watts peak load when boondocking.

* This post was edited 11/21/21 12:21pm by pianotuna *


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

Gdetrailer

PA

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Posted: 11/20/21 10:51am Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:



I've never overloaded my yahama 3000sieb, except when deliberately trying to do so. To be fair, I do have a load support inverter/charger. The generator does have remote electric start and I use it sparingly.

I do use a watt meter--and on shore power I've never used more than 7200 watts peak load (how--I have 2 auxiliary shore power cords). Average load at -30 is about 4300 watts (per hour so 4.3 kwh). But we are talking summer time, and the living is easy.

My rv behaves as if it were on shore power full time.

I deliberately limit my 30 amp consumption to 23 amps, which is what the Yamaha outputs.

23 x 120 = 2760 watts peak load when boondocking.



In the OPs case..

2 RVs with 50A shore power = 24Kw
1 RV with 30A shore power 3.6Kw

Fair chance that the folks with 50A shore power will easily end up tripping the gen. Their rigs have a 50A breaker so they can draw 50A (6,000W) on each leg which means the generator breaker now becomes the limiting factor.

Not everyone understands the idea of "conservation", energy management or energy sharing.

Very few RVs are factory built with battery "load support" which uses a big inverter and battery bank.

A lot of rigs with 50A shore connection are large enough to have two 13.5K BTU A/C units or at least one 15K BTU A/C unit.

One big 6Kw or larger gen most likely will require some shed to allow the gen to stay, lifting and moving 6kw+ gens isn't easy, perhaps if one was a body builder then the weight of that size gen would be a simple warm up exercise.

Your attempting to split 6Kw across three rigs, essentially is the same as attempting to run a 13.5K A/C from a 2Kw gen.. Some folks have been successful under ideal conditions with a bunch of mods, but more often than not, have failed at that attempt when conditions like temps and elevation are less than optimal.

A 6Kw gen would be easily swamped by just having the A/C compressors on three RVs attempting to start at the same time, it isn't like you are going to sit there and load manage by attempting to time the compressor start up each time each rig needs to turn on the compressor.

I can assure you, once you step above the small 4Kw gens, the noise level and fuel consumption get much worse.

Far better to have each RVr bring their own 3.5K inverter gen to the party, it will be less noise, less fuel consumption and each person must handle their own gen issues like fuel and noise..

valhalla360

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Posted: 11/21/21 01:07am Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:


Something else to consider, the bigger gen you go, the much louder it will be, somewhere I have a link to a video I took with a sound meter for my 8500W 13HP gen, very, very loud.. I use good quality hearing protection when I am near it when running.


With a large semi-permanent installation, you can move it further away and/or build a sound enclosure that negates the sound level.

I played with simply putting a piece of plywood between the generator and the trailer this summer and it was easy to hear the difference. This was just a plain piece of plywood, not an enclosure and no sound absorbing materials.


Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV


valhalla360

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Posted: 11/21/21 01:11am Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:



In the OPs case..

2 RVs with 50A shore power = 24Kw
1 RV with 30A shore power 3.6Kw

Fair chance that the folks with 50A shore power will easily end up tripping the gen. Their rigs have a 50A breaker so they can draw 50A (6,000W) on each leg which means the generator breaker now becomes the limiting factor.


You are confusing the theoretical peak load with the realistic peak load. Most 50amp rigs never hit anywhere close to their theoretical peak.

30amp it happens but even there it's for a second or two then drops back to something closer to 10-15amps. As long as everyone's air/con compressor doesn't kick over at the exact same time, you can have a generator quite a bit lower.

Gdetrailer

PA

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Posted: 11/21/21 11:25am Link  |  Quote  |  Print  |  Notify Moderator

valhalla360 wrote:

Gdetrailer wrote:



In the OPs case..

2 RVs with 50A shore power = 24Kw
1 RV with 30A shore power 3.6Kw

Fair chance that the folks with 50A shore power will easily end up tripping the gen. Their rigs have a 50A breaker so they can draw 50A (6,000W) on each leg which means the generator breaker now becomes the limiting factor.


You are confusing the theoretical peak load with the realistic peak load. Most 50amp rigs never hit anywhere close to their theoretical peak.

30amp it happens but even there it's for a second or two then drops back to something closer to 10-15amps. As long as everyone's air/con compressor doesn't kick over at the exact same time, you can have a generator quite a bit lower.


Not "confusing" anything.

For all intents and purposes, the two RVs with "50A" shore connections are able to draw more power than the one that is 30A. The breakers on the gen now become the limiting factor.

A 6Kw gen can output a max of 25A at 240 or 2 120V at 25A each.

13.5K A/C when running will draw easily 13A (1560W)in the heat of the day not including startup surges. They will have a LRA current of 20A-29A (2400W-3480W)each. The LRA is why many folks struggle getting a 2Kw inverter gen to consistently start and run a A/C unit.

Typical 6Kw gens are combo 120V/240V, you can pull max of 25A at 240V or you have essentially two separate 120V only windings which provide 25A each.

if the 50A rigs were connected via a 50A-30A 120V adapter you have to stack two rigs on one 120V winding and one on the other 120V winding.

You could of course connect the 50A rigs to the 240V outlet but now you have two rigs stacked but yet the way 50A rigs are wired it will still have more loads on L1 than L2 and still have to share one leg heavily (generally the second A/C unit is put on the L2 circuit).

The result will still be someone losing out.

The fix is simple, either go much bigger than 6Kw or bring your own smaller gens. 9Kw-10Kw would be the min I would recommend, that gives you some hope that the two rigs stacked on the one leg will not easily trip the breaker on the gen.

Something else to consider when using 120/240 gens, uneven loading of the two 120V windings results in uneven and poor voltage regulation. The AVR samples from only ONE of the 120V windings resulting in rather poor voltage regulation if you stack the load unevenly (IE more load on the wrong winding).

Skibane

San Antonio, TX

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Posted: 11/21/21 11:28am Link  |  Quote  |  Print  |  Notify Moderator

valhalla360 wrote:

With a large semi-permanent installation, you can move it further away and/or build a sound enclosure that negates the sound level.


The military just digs a pit, and drops the generator in it.

(Erecting a tarp over the pit is recommended in rainy weather...)

valhalla360

No paticular place.

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Posted: 11/22/21 12:40am Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:

valhalla360 wrote:

Gdetrailer wrote:



In the OPs case..

2 RVs with 50A shore power = 24Kw
1 RV with 30A shore power 3.6Kw

Fair chance that the folks with 50A shore power will easily end up tripping the gen. Their rigs have a 50A breaker so they can draw 50A (6,000W) on each leg which means the generator breaker now becomes the limiting factor.


You are confusing the theoretical peak load with the realistic peak load. Most 50amp rigs never hit anywhere close to their theoretical peak.

30amp it happens but even there it's for a second or two then drops back to something closer to 10-15amps. As long as everyone's air/con compressor doesn't kick over at the exact same time, you can have a generator quite a bit lower.


Not "confusing" anything.

For all intents and purposes, the two RVs with "50A" shore connections are able to draw more power than the one that is 30A. The breakers on the gen now become the limiting factor.

A 6Kw gen can output a max of 25A at 240 or 2 120V at 25A each.

13.5K A/C when running will draw easily 13A (1560W)in the heat of the day not including startup surges. They will have a LRA current of 20A-29A (2400W-3480W)each. The LRA is why many folks struggle getting a 2Kw inverter gen to consistently start and run a A/C unit.

Typical 6Kw gens are combo 120V/240V, you can pull max of 25A at 240V or you have essentially two separate 120V only windings which provide 25A each.

if the 50A rigs were connected via a 50A-30A 120V adapter you have to stack two rigs on one 120V winding and one on the other 120V winding.

You could of course connect the 50A rigs to the 240V outlet but now you have two rigs stacked but yet the way 50A rigs are wired it will still have more loads on L1 than L2 and still have to share one leg heavily (generally the second A/C unit is put on the L2 circuit).

The result will still be someone losing out.

The fix is simple, either go much bigger than 6Kw or bring your own smaller gens. 9Kw-10Kw would be the min I would recommend, that gives you some hope that the two rigs stacked on the one leg will not easily trip the breaker on the gen.

Something else to consider when using 120/240 gens, uneven loading of the two 120V windings results in uneven and poor voltage regulation. The AVR samples from only ONE of the 120V windings resulting in rather poor voltage regulation if you stack the load unevenly (IE more load on the wrong winding).


Clearly you still are missing the point.

Sure two 50amp rigs "are able" to draw more than a single 30amp rig...but that doesn't mean they will draw anything close to the 12,000w theoretical max. In point of fact, they are not rated for 12,000w continuous but only 80% of that. In real world practice, getting it down into the 3000w continuous with no noticeable impact on lifestyle...yes, if you purposely turn everything on, you can push it up in the 6-7kw range.

With modest attempts to control usage, getting it down to around 1700-2500w is very much viable with minimal impact on lifestyle.

You seem focused on being able to supply the theoretical max. Even electrical codes reduce the mandated supply when servicing multiple circuits because it's very rare for all of them to be maxed out.

valhalla360

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Posted: 11/22/21 12:44am Link  |  Quote  |  Print  |  Notify Moderator

Skibane wrote:

valhalla360 wrote:

With a large semi-permanent installation, you can move it further away and/or build a sound enclosure that negates the sound level.


The military just digs a pit, and drops the generator in it.

(Erecting a tarp over the pit is recommended in rainy weather...)


Problem with a pit is it also needs drainage (even with a tarp).

Plus without a platoon of healthy strong 18yr olds to do the digging, that's a lot of work. Much easier to build a small shed, insulate it and provide some ventilation.

Skibane

San Antonio, TX

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Posted: 11/22/21 02:18am Link  |  Quote  |  Print  |  Notify Moderator

valhalla360 wrote:

Plus without a platoon of healthy strong 18yr olds to do the digging, that's a lot of work.


In soft soil, it's 20 minutes for a tractor with a backhoe.

In rocky soil, add another couple hours.

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