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Topic: will a 1000 watt generator run a 5000 btu AC with no problem

Posted By: lloyd528 on 04/10/09 08:07am

Does anyone have an opinion about running a 1000w generator like the Honda eu1000i generator with a small 5000 btu air conditioner for a 13ft fiberglass rv? Can it be done or should I get the 2000 watt even though it is more expensive and wait till I have the money?


Posted By: david_42 on 04/10/09 08:19am

The eu1000i will run the average 5000 btu a/c no problem.

But, it will not be able to start one and I doubt you would be able to find a soft-start kit for that small of an a/c.


Posted By: ddav15 on 04/10/09 08:23am

A/C amps required vary alot depending on the model and year. The Honda 1000 puts out about 8 amps I think, that should be enough to run a 5000 btu but check the A/C amps required. I would recommend the 2000 because it won't have to work as hard to run the little A/C and will be quiter due to the engine not running as fast to power the A/C.


Posted By: Rollincool on 04/10/09 08:21am

I would vote for a yes.


Posted By: tvman44 on 04/10/09 08:32am

I believe you will have trouble starting the 5,000, if started it will probably keep it running. Get a 2,000 watt and be sure.


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Posted By: lloyd528 on 04/10/09 08:35am

what is a soft start kit? Where would I check to see if there are any available for a small AC like a 5000 btu? If they are available, it sounds like I could get away with the 1000 watt generator and save a lot of money...thanks


Posted By: big dave on 04/10/09 11:14am

I googled "watts to btu conversion" and found that 1000 watts = 3412 btu.


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Posted By: larry cad on 04/10/09 11:25am

windriderjr wrote:

larry cad wrote:

To convert BTU to watts, multiply BTU X .293. 5000 X .293 = 1465 watts.

To calculate amps from watts divide by voltage. 1465/120 vac = 12.2 amps.

That is the "running" amps. The starting amps will be about 3 tims that, or about 36 amps to start. Check the rating of the generator to see if it can supply those amps on starting and while running and you will have your answer.


I question the math there...

My AC is 13,500 BTU. That would mean it is demanding (13,500 X .293 = ) 3,955.5 "running" Watts or 32.9625 Amps. My TT has a 30 Amp cord and I don't strain my Honda EU3000is running the A/C... According to your math, My TT should explode every time my A/C starts



Hmmmm......you are right, so I am missing something. I've tried to research it and can't come up with an answer. Perhaps some of our mathmaticians on here can help. What am I doing wrong?




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Posted By: larry cad on 04/10/09 11:28am

big dave wrote:

I googled "watts to btu conversion" and found that 1000 watts = 3412 btu.


I believe that is correct which would give 1465 watts to run a 5000 btu A/C, or 1465/120v= 12 amps which is what I said. However, I am admitting that is incorrect based on the previous post. I just don't know why. I believe the problem involves some kind of "time" factor.

Anybody! Anybody!!




Posted By: larry cad on 04/10/09 08:54am

To convert BTU to watts, multiply BTU X .293. 5000 X .293 = 1465 watts.

To calculate amps from watts divide by voltage. 1465/120 vac = 12.2 amps.

That is the "running" amps. The starting amps will be about 3 tims that, or about 36 amps to start. Check the rating of the generator to see if it can supply those amps on starting and while running and you will have your answer.

There are solid state soft starters available, but they are expensive, and very limited. My understanding is that they cannot be used on compressors because of the capacitor start in A/C units and also because of the torque requirements on A/C compressors. Better off investing in a larger generator if yours won't work.


Posted By: smkettner on 04/10/09 09:17am

Go down to your Honda dealer and see if he has one to test it.
Doubt it will run it at all, let alone "no problem"


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Posted By: windriderjr on 04/10/09 10:12am

larry cad wrote:

To convert BTU to watts, multiply BTU X .293. 5000 X .293 = 1465 watts.

To calculate amps from watts divide by voltage. 1465/120 vac = 12.2 amps.

That is the "running" amps. The starting amps will be about 3 tims that, or about 36 amps to start. Check the rating of the generator to see if it can supply those amps on starting and while running and you will have your answer.


I question the math there...

My AC is 13,500 BTU. That would mean it is demanding (13,500 X .293 = ) 3,955.5 "running" Watts or 32.9625 Amps. My TT has a 30 Amp cord and I don't strain my Honda EU3000is running the A/C... According to your math, My TT should explode every time my A/C starts


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Posted By: 0dell on 04/10/09 10:28am

It's not a soft start kit. It's called a hard start capacitor. They are normally used in older air conditioners that get hard to start over time. You should be able to get one at your local Johnstone or similar business. Really easy to wire in parallel with the existing start capacitor.


Posted By: winbadgers on 04/10/09 11:44am

That would assume every air-conditioner has exactly the same efficiently which we all know is not the case. I believe the factor you are using is what heat is generated by consuming power. I also believe you have the values inversed. 1 watt = 3.415 BTH/hour. Or 1 BTU/hour=0.293 Watts.

In other words, lets say your computer consumes 600 watts. That piece of equipment would create approximately 2049 BTU/hour of heat.

As far as I know there is no direct conversion from watts consumed to BTU/hour heat by furace or air conditioning. It just would not be possible in my mind.


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Posted By: canoe on top on 04/10/09 12:01pm

I would think, on the A/C, the owner's manual or the manufacturer's website, it would give the amps required to run that unit. That would tell you how big a generator you need.


Posted By: smthbros on 04/10/09 12:20pm

big dave wrote:

I googled "watts to btu conversion" and found that 1000 watts = 3412 btu.


That works for heating since electric elements are pretty much all the same efficiency. For AC you should take into account the SEER (seasonal energy efficiency rating; or btu per watt). The last window unit I looked at had a SEER of 9.8. Hence a 5000 btu, 9.8 SEER unit should use about 510 watts.


Posted By: smkettner on 04/10/09 10:12pm

Kipor was a much better deal a few years ago. If buying today I would get a Honda.
My Kipor still runs fine though.


Posted By: FredAr on 04/11/09 08:16am

lloyd: Smart. The Honda 2000 is simply an amazing littler beast. I have a 9 year old and a 1 year old - they run the same! The both run a Coleman 9200 A/C (8300BTU?) smartly.

Oh, and surge on the average is roughly 1.5 of running, or less. Rough rule of thumb.

Good luck.

P.S. I also have a 3000, love it, but for stationary duty in a property without power. Quiet as a church mouse, but stays in one place because of its weight.


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Posted By: Excalibur3000 on 04/10/09 12:26pm

The reason a simple equation does not work is because you are not converting electricity into heat. In fact, you are using electricity to run a heat pump system (your AC). While this may seem counterintuitive, you can think of it this way - if you use say 100 W of electricity to run a heating element, the electrical energy is being converted to heat energy, and the conversion attempted earlier works. By contrast, your AC is not converting anything - it is moving heat from inside your trailer to the outside, where it still carries substantially the same amount of thermal energy. As it turns out, a standard has been developed that represents the ratio of thermal energy to electrical input energy - EER. EER is related to SEER (EER = SEER * 0.9) which you have probably run into if you have ever seriously looked at or shopped for a home air conditioner. Home AC units must all have a minimum SEER of 13, which was implemented in 2006 to help with the power shortage/rolling blackout issues. A higher SEER menas more cooling capability for the same amount of electricity, or less electricity for a fixed amount of cooling capability.

If I remember right, RV AC's have lower SEER's than residential stuff. So, assuming a 5000 BTU /Hr Unit with a SEER of 10 would give us 5,000*0.293/(10*.9) = ~163 W, or 1.5 A. This must be added to the fan load to get total operating draw. Now, add on top of this the inrush current necessary to start the unit (varies between 3 and 10 X operating), and you get total amps needed. Multiply by 110 V again to get Watts.

Really, by the time you track down all the info you need (Actual SEER, fan amps, starting current), it is just as easy to find the manufacturer, somehow track down their info, and ask them directly.

All that being said, to the OP - I have dual 2000's and they are nice machines. Unless you are really struggling with being able to lift/move them, I would spend the little extra dough and buy a 2000. They also have the power to run other stuff, power tools, etc. Also, you will almost always be running your converter with your AC if you are boondocking unless you flip the breaker or otherwise disconnect it, it will add to your load. Also, a 2000 will be able to run a microwave. All some things I would be thinking about if I were facing your decision.

Casey


Posted By: whjco on 04/12/09 05:53pm

I just purchased one of these:

http://www.stylefeeder.com/i/2291d3x1/2009-Model-Magna-3000-Watt-Portable-Inverter-Generator-New-2nd-Generation-Quite-Lightweight-Null

It's cheaper than the Honda and it's a 3000 watt unit that's already equipped with a 30A 120V receptacle and is supposed to be able to power the newer 13,500 btu AC units.


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Posted By: mgbogue1 on 04/12/09 10:45am

lloyd528 wrote:

Does anyone have an opinion about running a 1000w generator like the Honda eu1000i generator with a small 5000 btu air conditioner for a 13ft fiberglass rv? Can it be done or should I get the 2000 watt even though it is more expensive and wait till I have the money?


I'd get the 2000. If you're like most, eventually you'll move up to a bigger unit, and you'll need the extra power. It's the "Tim Taylor" effect. MORE POWER!!!


Posted By: marc71 on 04/10/09 12:43pm

winbadgers wrote:

marc71 wrote:

First thing... Does honda make a 2000 watt generator? I thought it went from 1000 to 3000, you can get a kit to make two 1000 watt genny's run together. I have a 1000 watt genny that I take to races and it barely runs my microwave... With that being said, get the Honda 3000 and have all the power you'll ever need.



Yes the make a 2000watt generator. In fact, it is their most popular model.

http://www.hondapowerequipment.com/products/modeldetail.aspx?page=modeldetailĀ§ion=P2GG&modelname=EU2000i&modelid=EU2000IAN


You know I thought about it after I wrote this and now I do remember the 2000 model, I don't know what I was thinking! I do know that camping last week there was a neighbor that had a 3000 and I could not get over how quite it was and how it was good for everything in the camper.


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Posted By: marc71 on 04/10/09 12:08pm

First thing... Does honda make a 2000 watt generator? I thought it went from 1000 to 3000, you can get a kit to make two 1000 watt genny's run together. I have a 1000 watt genny that I take to races and it barely runs my microwave... With that being said, get the Honda 3000 and have all the power you'll ever need.


Posted By: MeandMyLabs on 04/12/09 10:21am

I have a 7000 BTU AC in my hunting cabin and run it off a 2400is Yamaha. The Yammi handles it...but barely at start up. If I am watching TV and the AC compressor kicks in, the TV will turn off. I would think from this experience that a Honda 2000 would be the absolute minimum you would be able to start the 5000 BTU AC with. When I set up my cabin, I was shocked by the increased demand of this window mount AC unit in comparison to a RV unit. JMHO


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Posted By: Island-Slacker on 04/11/09 12:45pm

supco super boost - they have several add on capacitors that will assist compressor starting


as for amp draws of a/c units 1 amp is roughly 1000 btus a 5000 btu a/c will have run amps approx 5 amps a 13,000 btu ac will pull approx 13 amps

the above statement is an approxmate estimation not exact - unit efficency will make the amp/btu ration vary a bit older units typically draw on the higher side while newer units draw on the lower side


Posted By: winbadgers on 04/10/09 12:10pm

marc71 wrote:

First thing... Does honda make a 2000 watt generator? I thought it went from 1000 to 3000, you can get a kit to make two 1000 watt genny's run together. I have a 1000 watt genny that I take to races and it barely runs my microwave... With that being said, get the Honda 3000 and have all the power you'll ever need.



Yes the make a 2000watt generator. In fact, it is their most popular model.

http://www.hondapowerequipment.com/products/modeldetail.aspx?page=modeldetail§ion=P2GG&modelname=EU2000i&modelid=EU2000IAN


Posted By: winbadgers on 04/11/09 08:48am

I think the EU2000 is a very good choice for you situation. I have that model and love it.


Posted By: winbadgers on 04/10/09 12:47pm

marc71 wrote:

winbadgers wrote:

marc71 wrote:

First thing... Does honda make a 2000 watt generator? I thought it went from 1000 to 3000, you can get a kit to make two 1000 watt genny's run together. I have a 1000 watt genny that I take to races and it barely runs my microwave... With that being said, get the Honda 3000 and have all the power you'll ever need.



Yes the make a 2000watt generator. In fact, it is their most popular model.

http://www.hondapowerequipment.com/products/modeldetail.aspx?page=modeldetailĀ§ion=P2GG&modelname=EU2000i&modelid=EU2000IAN


You know I thought about it after I wrote this and now I do remember the 2000 model, I don't know what I was thinking! I do know that camping last week there was a neighbor that had a 3000 and I could not get over how quite it was and how it was good for everything in the camper.



Keep in mind the 3000watt model is a bear to lift and move around. You can actually get two 2000 watt models and connect them together for about the same price and have 4000 watts. This also make it a lot easier to handle IMO. Also if you only need 2000 watts you now have the option to take only one. Just my 2 cents.


Posted By: gumbyjb on 04/10/09 12:09pm

The A/C unit should have a placard on it somewhere giving the power requirements. Looking on the internet for normail window A/C untis, it seems that most 5000 BTU A/C units run on between 5 and 6 amps. I'm not sure if an RV A/C would be different, but shouldn't be too far from that...


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Posted By: lloyd528 on 04/10/09 09:44pm

All I can say is wow.....I ask a question and get a bunch of electrical engineers answering the questions....maybe that's an exageration but holy geeeze, more replies than I ever expected on this topic....as a member of the FiberglassRV Forums, I would never get this many answers in such a short period of time. I am thrilled to have found this Forum for RV enthusiasts. Is it the most frequented forum for folks who own RVs?

I know what to do now without question.....buy the Honda 2000 period. I considered a Kippor but I get the feeling that it is worth the extra dollars to spend on the Honda.

Thank you again to all who responded to my question...you saved me money and time.

Lloyd


Posted By: Pete D on 04/12/09 11:00pm

LLoyd has asked this question on at least three forums that I have seen, and generally the answer has been no. However, on the Yahoo Scampers forum, another Lloyd posted this answer:

"Could a Honda eu1000i generator handle a new 5000btu Frigidaire AC?
---------------------------------------------------------------
I have found that the new Frigidaire 5000 btu will start easily
and run on a 1k generac/mitsubishi/troy generator. The new Gold
Star 5000btu will also start and run well on a 1k.

They are not like the old units that required about 1.5k to
start them."


1998 Ranger 4.0 4x4
1991 Scamp 13'


Posted By: sushidog on 04/13/09 01:27pm

My Honda eu1000 is barely big enough to start and run my 5,000 BTU Maytag a/c that came with my Aliner (at sea level). I must take it off eco mode and plug the a/c into the Honda directly, so there's no power loss through the converter. However, I always thought my a/c was overworking the little Honda.

Here's a pic of my new genny I got last week, just to run my a/c.





It's just big enough to reliably start and run the little 5,000 BTU a/c in my Aliner. I can even recharge my battery and run some lights while simultaneously running my a/c with this new one.

I wanted an inexpensive Chinese genset, cause I won't be using it much, but I was afraid of buying a no-name brand off E-bay. I felt a little safer getting this 1,200w (1,500w surge) Triron RT-1800 from Home Depot online, as it comes with a year warranty from a company I know and trust.

Though not as quiet as the Honda and Yamaha's 59db, at only 63 db it's not as bad as some so called "camping generators" out there. I like that the pitch doesn't change when a load is applied, like the inverter models. I find a constant noise level and pitch less annoying that one that varies up and down. For less than 1/3 the price of the eu2000, shipped to my door, I had to give it a try. It's 10 lbs heavier and slightly bulkier than the eu2000 (it has a huge muffler,) but I guess you get what you pay for.

It won't start my Dometic microwave though. My Dometic manual says it draws 1,000 watts, but failed to say what the starting wattage is. It must take over 1,500 watts to start! The eu2000 Honda which is really rated at 1,600w (2,000w surge) should start and run a small microwave fine - if you can afford it's $1,000+ price tag.


2006 Aliner LXE
2006 Chevy Cobalt SS



Posted By: lloyd528 on 04/13/09 03:08pm

thanks for the tip on the TRIRON from Home Depot...that information was very helpful.....I won't be using one much either. I will look into this one.thanks again, lloyd


Posted By: lloyd528 on 04/13/09 07:25am

Yes pete, I frequent Fiberglass Rv but there are never nearly as many responses due to lower traffic there. I also tried the Scamp forum to see if I could balance more opinions. Hope I am not being a pest here but I do like to get the best take I can on different issues. Rv.net seems to be the best so far when it comes to questions that apply to RVs in general and not just small fiberglass ones.

Lloyd


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