Generators and Airconditioners

bubblehead

Veteran Expediter
I have noticed sporadic post about this subject in many different threads the latest being in June Location....Since it is a critically important subject, I thought I might try to get members to direct their experiences and suggestions here.

Because of a breakdown of my current diesel generator, I find myself keeping cool with a Honda eu2000i.This is supporting a Dometic 14000 btu split unit with some limitations...bottom line I am keeping cool and comfortable.

After a volley of discussions in the June Locations section concerning the Honda, I researched some more and found that the gennys are popular in the boating world and are used to power 16,000 and 16,500 btu systems while on ECO mode. Kinda makes me wonder if our industry has been sold a bill of goods with excessive and expensive generator setups.

Hers is a copy from one of those boating forums:

Understanding the Dometic SmartStart
Hello from Dometic Marine – Makers of Cruisair and Marine Air Systems Brand Air Conditioning and Refrigeration Systems.

We’ve been monitoring this thread and decided to join the forum to lend some expertise and to help everyone out. We have reviewed the forum rules and regulations regarding commercial interests, and we hope that this post in no way offends or violates anything. All we want is for everyone to have the facts. The new SmartStart is a revolutionary new product that is unlike any other soft starter or hard start add-on in the industry. It is very important to understand how it differs so you can make the right choices for your individual situations.

Important information about the dangers of Portable Gasoline Generators
Before we begin, it is important to clearly state that Dometic does not condone the use of portable gasoline generators for any marine application since both the US Coast Guard and the ABYC strongly caution against it. Portable gasoline generators are not properly marinized and they present life-threatening risks and dangers, including carbon monoxide poisoning and risk of explosion since they are typically not ignition protected. For more information, please refer to the USCG bulletins on this topic available online at http://www.uscgboating.org/assets/pd...bscscan68a.pdf and http://www.uscgboating.org/assets/pdf/recalls/BSC74.pdf. Also, please refer to the ABYC document TH-22 (http://www.abycinc.org/th-22.pdf) where they discuss the use of portable generators on boats .

Test Setup and Equipment
In order to provide you with the most accurate information, Dometic obtained a Honda EU2000i generator and a Supco SPP6E Super Boost for side-by-side testing with the new Dometic SmartStart. Both the Honda and Supco products are very good, and by no means was this study conducted in order to put down either one. This study is meant to help everyone better understand how the SmartStart is different and where and why it can solve the problems discussed in this thread where other products cannot.

The current surge caused when an air conditioner compressor starts up is very short in duration, typically 150-300 milliseconds. Hand-held clamp-on current meters typically cannot measure this surge accurately because they typically display an averaged reading about once per second. As a result, the reading obtained with a clamp-on meter is always much lower than what has actually occurred. For our SmartStart development which started over one year ago, we at Dometic developed a custom and very specialized piece of test equipment to accurately capture and measure the start surge accurately. This specialized equipment along with an oscilloscope was to carry out the following study. Below is a photo of the test setup which conducted outdoors so we could run the Honda generator. We used a Cruisair model STQ16-R410A Turbo self-contained 16,000 BTU air conditioner for most of the testing.

Technical Differences between the Dometic SmartStart and the Supco SPP6E (Class E Super Boost) The Supco SPP6E Super Boost device consists of a 88-106MFD start capacitor connected in series with an electronically-controlled, solid-state potential relay. Using voltage sensing, it connects the start capacitor in parallel to the air conditioners run capacitor during the start up. As the voltage across the run capacitor (Run winding to Start winding) increases during the start, the device switches out the start capacitor at a preset level or after a timeout period expires. This sequence partially mimics the behavior of a full hard-start kit (start cap with a mechanical start relay) but not exactly. A true potential start relay has its coil connected across the compressor Common and the Start winding. The voltage behavior between these two compressor terminals is a little more predicable during a start-up. As a result, a true start relay can accomplish a more reliable disengagement of the start capacitor. Nevertheless, the Supco Super Boost does provide a good portion of the benefit of a true hard-start kit and reduced cost. Based on our measurements (shown below), the Super Boost provided a startup current surge reduction of about 20-25%.

The new Dometic SmartStart is completely different. The SmartStart uses a microprocessor to provide real-time control of the applied voltage and current to the Start winding and Run winding independently. The voltage applied to the start winding is also shifted in phase by an internal start capacitor. The application of voltage is so precise that each half alternation of the applied AC power is individually handled by the microprocessor. Then, using back EMF detection, the SmartStart determines when the motor’s rotor actually begins to rotate. The SmartStart then accelerates the rotor until it has achieved full speed. Then, at a very precise moment when the current waveform passes through zero, the SmartStart seamlessly bypasses its internal control devices with relays to connect the Run winding directly with L2 and disconnecting from the Start winding.

The SmartStart’s intelligence then even goes beyond this. Using the information it gathers from each start, it actually “learns” from what happened during one startup to determine what to use on its next startup. So, immediately after installing and using it on for the very first time, the SmartStart may take up to 10 startups for it to optimize itself to the absolute lowest possible starting current. After that, it continues to fine tune its startup behavior from start to start, up or down, depending on age of the compressor, environmental conditions, and voltage.

The result of this microprocessor-controlled automation and recursive learning is the absolutely lowest possible startup current required for each individual compressor and SmartStart combination. For all models of the SmartStart, the average start-up current reduction achieved is 65%.

Test Results
Two sets of tests were run: One on utility power and one on generator power. The Honda EU2000i has an “ECO” switch that allows for economy mode operation. This economy mode of course results in the generator running at a lower throttle setting to save fuel. However, there is a trade-off. When ECO mode is turned ON, the generator cannot respond quite as quickly to rapid changes in load current. Under certain test conditions, the compressor start surge on generator power caused the generator’s output voltage to drop drastically and to become erratic when the compressor start faltered, and also caused the generator’s maximum output current to be clamped. So, in order to accurately quantify what each hardware configuration would do, accurate start current data was captured using utility power. Later in the generator tests, instantaneous voltage fluctuation was also measured. In the end, both current surge and voltage drop do matter since voltage drop can dramatically and sometimes detrimentally affect other equipment that may be operating on the same generator.


TestData.jpg



Analysis The Honda EU2000i is quite a potent little device. Regardless of the start component configuration, it was able to start the 16000 BTU system reliably when the ECO mode was turned off. When the ECO mode was turned on, however, the generator had trouble with the standard configuration and with the Supco SPP6E installed. The Supco Super Boost did help, but the resulting voltage drop to around 67V (46%) was problematic in that it did sometimes reset the digital controls. Other equipment running off the same generator would have also been affected.

The SmartStart made a dramatic difference. With the ECO switch turned on, the generator was able to tolerate the 18 amp start surge with only about a 20% drop in voltage. With the ECO switch turned off, the generator didn’t even flinch (i.e. no measurable voltage drop).

Summary
As was cited elsewhere in this thread, the Honda EU2000i can support a 16,000 BTU air conditioner without any added hardware. But as our testing showed, this would only work if the ECO mode was turned off. Adding the Supco SPP6E provides a marginal improvement, but for our specific test with the 16000 BTU system, it could not guarantee a reliable start-up if the generator was operating in ECO mode. Beyond this, if other equipment is already loading the generator (e.g. sea water pump), that will further reduce the available amperage for the compressor start-up. Adding the Dometic SmartStart provides a dramatic improvement, provides a reliable start under almost all conditions, and will allow the generator to be run in ECO mode, which will certainly reduce fuel consumption .

Dometic is very happy to contribute to this forum; however, we cannot guarantee that someone will always have the opportunity to monitor it at all times. We will do our best to return to this thread in the coming days to answer any follow-up questions. In the future, others from Dometic may use this user ID to answer other questions on this forum.

Thank you for your continued interest and support.

Thank you.
M. Giovanetti
Director of Technology
Dometic Marine Corporation

http://www.sailnet.com/forums/gear-maintenance/62158-honda-eu2000i-air-conditioning

Not to sell Dometic or Honda, but if these guys are able to operate 16-16,500 btu systems with a small generator then our industry should be able to also.
 

ysracer

Expert Expediter
Owner/Operator
That device is manufactured by Hyper Engineering and is available from them much cheaper than from Dometic. Hyper calls it "Sure Start". I bought mine on eBay and added it to my Dometic 13.5k AC unit.

It made a dramatic difference in that, my Ryobi 1800/2200 inverter generator was able to start the compressor in Eco mode, whereas it could not run the AC previously, even at max rpm's (Eco mode off).

However, the single Ryobi could not power the AC under any circumstance when ambient temp was in the 90's or above. I bought a second Ryobi, a Honda parallel cable and, in Eco mode, they barely notice the compressor startup demand. Will a single Honda 2000 work ? Some have success, others don't.

I got tired of fiddling with 2 gennies, now using a single Yamaha 2400ishc. (he for high current). It does the job with ease. Larger displacement engine than others, so it never revs high and is super quiet and mellow sounding.
 

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bubblehead

Veteran Expediter
That device is manufactured by Hyper Engineering and is available from them much cheaper than from Dometic. Hyper calls it "Sure Start". I bought mine on eBay and added it to my Dometic 13.5k AC unit.

It made a dramatic difference in that, my Ryobi 1800/2200 inverter generator was able to start the compressor in Eco mode, whereas it could not run the AC previously, even at max rpm's (Eco mode off).

However, the single Ryobi could not power the AC under any circumstance when ambient temp was in the 90's or above. I bought a second Ryobi and a Honda parallel cable and, in Eco mode, they barely notice the compressor startup demand. Will a single Honda 2000 work ? Some have success, others don't.

I got tired of fiddling with 2 gennies, using a single Yamaha 2400ishc. (he for high current). It does the job with ease. Larger displacement engine than others, so it never revs high and is super quiet and mellow sounding.

I have looked at Yamaha also but when it was time to make a quick buy, the Honda was readily available. I will check out the Sure Start. Currently the little Honda is powering the Dometic 14,000 btu with some restrictions. I do fear in the 100+ degree weather it will falter unless I modify the Dometic and/or the generator setup.
 

gotto_03801

Seasoned Expediter
I have looked at Yamaha also but when it was time to make a quick buy, the Honda was readily available. I will check out the Sure Start. Currently the little Honda is powering the Dometic 14,000 btu with some restrictions. I do fear in the 100+ degree weather it will falter unless I modify the Dometic and/or the generator setup.
not saying the Hondas are bad units. but the Honda EU2000 is only like 1600 watts and 16 amps after the surge start and that lasts for 10 seconds I belive. I know the Yamaha 2400is is a 2000 watt genset after the surge start I for get what the amp rating on it is though. and you can buy the yamaha's off amazon also if that's the unit you truly want
 

xiggi

Veteran Expediter
Owner/Operator
People do use them, I tried one for about two weeks and knew it wasn't for me.
 

Unclebob

Expert Expediter
Owner/Operator
A lot of the heat leaks back into the van before it can exhaust outside. You have to blow the air directly on you to stay cool.

Ok for sleeping but it won't cool the van while you're sitting around waiting for a load.


Sent from my iPad using Tapatalk
 

xiggi

Veteran Expediter
Owner/Operator
They aren't strong enough to cool an entire van well and I don't like having stuff in the way in my van.

I have a rooftop, 13500 btu
 
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xiggi

Veteran Expediter
Owner/Operator
A rooftop will run in the 6 to 700 range and then you need it installed. A generator from 400 to 2 grand depending on size, quality and loudness.
 

ntimevan

Veteran Expediter
Owner/Operator
Portable AC's will work .... I bought a used 1 for $50
at a garage sale .. came with remote and attachments ... 8,000 btu... all I had to do was make a window bracket .... and use a 1 gallon jug for drain pail .. 2300 watt ( $300.) Generator with 2 1/2 gal. gas tank ... runs 10 hours on 2 gal. gas ...very little strain on gen... Importatant item ... 25 ft. 12 gauge extention cord (best -construction grade ) $ 35. at Home Depot ... I also wrap Vent tube with cheap solar blanket ... because it does get Hot ..... in La. last weekend 100 to 103 degrees outside ..
70 to 72 degrees inside my van 6 x 8 ft. living area ...
Maybe Ovm will Chirp in on how his works better now with 12 gauge cord ... he tested it out a week ago in NC ...
 

westmicher

Veteran Expediter
We use household 5,000 BTU air conditioners in our super-well insulated vans. A 2,000 watt surge, 1,600 atts running generator easily runs these air conditioners. They use 1 gallon of gas every 6-8 hours, depending on the outside temperature!
 

ysracer

Expert Expediter
Owner/Operator
A rooftop will run in the 6 to 700 range and then you need it installed. A generator from 400 to 2 grand depending on size, quality and loudness.


I got a good deal ($450.00) on a 13,500 btu rooftop Dometic from Camper's Paradise in Charlotte. Lugged it on to Tuscaloosa and decided it was so hot it was going on NOW. Off to Lowes for a sabre saw, climbed onto the roof and had at it :nailbiting:
 
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bubblehead

Veteran Expediter
We use household 5,000 BTU air conditioners in our super-well insulated vans. A 2,000 watt surge, 1,600 atts running generator easily runs these air conditioners. They use 1 gallon of gas every 6-8 hours, depending on the outside temperature!
Have you tried the Honda eu 1000i, 1,000 watt surge, 900 watts (7.5 amps) running? Or it's equivalent? On some 5000 BTU ACs, the spec's show amps at 4.8 ( http://www.homedepot.com/p/LG-Electronics-5-000-BTU-Window-Air-Conditioner-LW5012/203127491 ) which would be 64% of the rated running watts. That should get about 5.5 hrs. on the .6 gal tank. With an extended run tank (6 gal.), the total run time works out to about 60.5 hours.

The weight of the AC, 40 lb., plus the weight of the generator with fuel and oil, 32 lb., and finally the weight of the extended run tank and 6 gallons of fuel, 43 lb., given a total of 115 lbs. (77.2 lbs. with the extended tank empty) seems like a viable way to keep cool when not able to hook up to a power outlet.
 

westmicher

Veteran Expediter
Have you tried the Honda eu 1000i, 1,000 watt surge, 900 watts (7.5 amps) running? Or it's equivalent? On some 5000 BTU ACs, the spec's show amps at 4.8 ( http://www.homedepot.com/p/LG-Electronics-5-000-BTU-Window-Air-Conditioner-LW5012/203127491 ) which would be 64% of the rated running watts. That should get about 5.5 hrs. on the .6 gal tank. With an extended run tank (6 gal.), the total run time works out to about 60.5 hours.

The weight of the AC, 40 lb., plus the weight of the generator with fuel and oil, 32 lb., and finally the weight of the extended run tank and 6 gallons of fuel, 43 lb., given a total of 115 lbs. (77.2 lbs. with the extended tank empty) seems like a viable way to keep cool when not able to hook up to a power outlet.
I tried a no name China made "1,200 " watt generator and it wouldn't start a 5,000 BTU air conditioner on "high cool" but probably would with a hard start capacitor. I don't know if the output was really 1,200 watts... but a 1,600 / 2,000 generator has enough headroom to run a 700 watt microwave while the air is running.

I really agree with your focus on light weight! Most drivers don't consider how much cargo weight they give up when they use a much larger generator, often include an exterior carrier, with a 13-15,000 BTU air conditioner... and how much more fuel they use to run all that. It really adds up! We spend a few days super-insulating our vans so we don't have to overpower the outside weather.

A 5,000 BTU air conditioner is super cheap to buy as well, often under $100 on sale.
 
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xiggi

Veteran Expediter
Owner/Operator
I need to step in one of your vans on a hot humid day. When we were talking it sounds like our insulation is similar. I just can't wrap my head around a 5000 cooling an entire van on a 90 degree day with real high humidity. I'd like to check it out.
 
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