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Anyone try the smaller 9200 BTU rooftop coleman polar cub units for AC?

according to their specs they only use 1700 watts to start and 1400 ish watts to run but can cool a camper just as well as a monster 13500 or 15000.

If this is true, this would open the door for smaller generator applications.

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There are quite a few members of the Yahoo Toyota campers group who have bought these and run them with a Honda 2000 with no problems. Mark, who I know well, is in Texas so hot and humid too. Another member I know is on this site too but I can't remember the name he uses here. He is running his with a Smarter Tools 2000 watt generator. Those cost just a little over 500 bucks at Home Depot.

Linda S

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Anyone try the smaller 9200 BTU rooftop coleman polar cub units for AC?

according to their specs they only use 1700 watts to start and 1400 ish watts to run but can cool a camper just as well as a monster 13500 or 15000.

If this is true, this would open the door for smaller generator applications.

Where did you find specs on startup load/current? All I see in the Coleman spec sheet is the "locked rotor" specs which is a worst-case-scenario of 7000 watts, i.e. 58 amps. Also full load cooling. I see nothing on start-surge. I don't use electric powered AC anywhere so have no first hand experience. Just often read the posts and problems posted. I've seen plenty of posts with Polar Cub 9200 users that could not use them with 2000 watt generators, and also many who could. One guy did a good job (electronics tech) of measuring current with his 9200 Polar Cub. It drew 24 amps @ 120 volts at first start but just for 1500 mircoseconds and then tapered back to 10-11 amps. One posted had a Yamaha 2000 watt generator and would not consistently start a Coleman Polar Cub 9200. He wound up getting a Coleman Mach I Power Saver (11K BTU) that worked well for him (less draw then the Polar Cub. ) That unit has a locked-rotor rating of 44 amps, as opposed to the 58 amps of the Polar Cub.

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Not all gensets, AC's and electrical systems are created equal! A small genset that will run an AC at sea level may not run it at a couple thousand feet altitude or on a hot humid day. A maintained electrical system with properly sized wires and clean contacts may run an AC where the same unit in a lesser electrical system will not. Heat and humidity are also a factor.

Most 2000 watt gensets will run an RV AC once it is started. The inrush of current to start an AC is referred to as LRA or locked rotor amps, this is the important number.

The LRA of the Polar Cub is advertised at a whopping 58 amps

Both these numbers are in a shop and can be affected, by other factors.

The LRA if the Mach 1 Power saver is 44 amps

The honda 2000 can provide a brief moment of 50-55 Amps, which suggests it will not start the Polar Cub, but it does and can do it on a regular basis.

Looking at the numbers it appears that the Mach 1 has a better chance of starting consistently on a 2000 watt genset. But you are in a borderline area where it may work most of the time, but not always.

I had an older 13.5K roof air that I could start and run on a Honda 2000. Knowing what I know today, I would say it could not work, but it did!

Then it is reported that Joe put a capacity thing in his AC and now it starts all the time. A possibility but requires someone more knowledgeable than me to figure out.

My opinion and worth what you are paying for it. HTH Jim

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I saw jde's and your locked rotor stats; but to me they don't matter much because whats the LRA of a coleman Mach iii?

whatever it is my little HF inverter does it. It did give me significant more trouble in KY at 92% humidity in 97 degrees than in OBX NC last summer at 91 degrees. I am unsure if elevation played a role or not.

Interesting stats on the Mach 1 PS; its clearly the champ on LRA but whats its stats on operating watts draw? because I had an issue there too; my evaporator was freezing like a huge ice ball then it would overload generator after like 1-2 hours this summer. It did this only on the most humid day the other days it ran fine.

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Operating watts and freeze up have nothing in common! The #1 issue I have seen (Bearing in mind I have not seen alot) in AC's is clogged filters and evaporators. This reduces air flow which in turn causes the unit to freeze up. So first would be checking that everything is clean. Then on humid days if you have the option increase the fan speed, which may prevent freeze up.

I posted a picture of my roof air evaporator on this site, it is so plugged it is amazing it works. I have not used my RV yet, it may not work all day!

Then there is always the possibility of low coolant causing the problem or improperly designed duct work.

And of course the disclaimer, I am not an AC tech, just another Bozo on the forum reporting my experience and what I have read. Jim

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Operating watts and freeze up have nothing in common! The #1 issue I have seen (Bearing in mind I have not seen alot) in AC's is clogged filters and evaporators. This reduces air flow which in turn causes the unit to freeze up. So first would be checking that everything is clean. Then on humid days if you have the option increase the fan speed, which may prevent freeze up.

I posted a picture of my roof air evaporator on this site, it is so plugged it is amazing it works. I have not used my RV yet, it may not work all day!

Then there is always the possibility of low coolant causing the problem or improperly designed duct work.

And of course the disclaimer, I am not an AC tech, just another Bozo on the forum reporting my experience and what I have read. Jim

In the context of my comment, which is successfully running AC off of a 2500 watt generator it has a lot in common; because if on 30 amp shore power you can have a frozen condenser and the AC still runs.

on the 2500 your watt demand increase to failure. to your point I checked the filters inside they were just cleaned, and on the roof the fins of what I could see looked pretty good the unit is only 4 years old; however I hit it on the roof of a parking garage 2 years ago and inside its dented pretty badly on something that may be the issue. I am thinking about tearing it off and replacing and if I am doing that I'd like the unit that draws the least watts and best locked rotor stats, for now that appears to be a Mach one PS... not the polar cub, right?

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When you have the filters out look up inside at the evaporator also. If you have kept the filters installed and clean on a four year old unit it unlikely will be an issue, but costs nothing to look! Mine has 20 years of crud in it!!

Also keep in mind when a Polar cub is discussed, is it several years old and less BTU then what is available today? They were smaller just a few years ago.

The #'s are Polar Cub LRA, 58.4 running watts 1225 desert conditions 1450 Cubic foot of air moved 200

Mach 1 LRA 45.6 Running watts 1080 desert conditions 1340 " 320

A 2500 watt genny would likely run either one with little issues, but I was only searching for a 2000 Watt genset. So I would be buying the Mach 1.

One thing I do not like is amount of humidity removed is not reported by the manufacturers. HTH Jim

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yep its settled; I'm going to get a mach 1 power saver. In addition to always running, it should lower the decibels of the generator as it wont have to spin up to much to power it.

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I like the BTU's of the Polar Cub and suspect it would keep the camper more comfortable by not cycling on and off as much. But numbers is numbers. I would guess that the Mach 1 is able to use less energy by using a higher quality compressor. So might run quieter also?? Might be able to run the fan at a lower speed also which would also keep the noise down.

We expect a full detailed report by the end of summer! Jim SW FL

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I like the BTU's of the Polar Cub and suspect it would keep the camper more comfortable by not cycling on and off as much. But numbers is numbers. I would guess that the Mach 1 is able to use less energy by using a higher quality compressor. So might run quieter also?? Might be able to run the fan at a lower speed also which would also keep the noise down.

We expect a full detailed report by the end of summer! Jim SW FL

Trying to figure out what generator will run what AC unit will always be a sort of "crap shoot." One reason being that few generator sellers give full specs on how much current the genset can supply for how long. Some good inverter companies DO give those figures but I've yet to see a generator seller give them. Some crucial specs would what the highest surge rating would be and for how much of a fraction of a second a generator can supply it. That's what can make or break the situation of starting an AC unit sucessfully if things are close.

For example - my Trace/Xantrex DR2412 inverter was sold as a 2400 watt unit. It is rated as thus: Continuous - 20 amps (2400 watts). 5 seconds duration - 35 amps (4200 watts). 100 milliseconds - 55 amps (6600 watts). 1 millisecond - 77 amps (9240 watts).

Now, how many generators have you seen sold as "2000 or 2500 watt" give specs showing they can supply 10,000 watts and for how long? I know Honda certainly does not give such info. In fact, Honda uses the BS marking scheme of calling their continuous-rated 1600 watt generatort a "2000" which is kind of misleading.

A correctly wired 20 amp duplex outlet in a house protected by a 20 amp breaker and with 12 gauge copper wire is good for at least 6000 watts for a second or two. A 30 amp outlet - like a house has for an electric dryer or a campground uses - with a 30 amp breaker and 10 gauge copper wire is good for over 10,000 watts for a short period of time.

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jde, agreed 1000%, as the 2500 unit I have from HF is really a 2000 continuous that trips on 2001.

so In theory if I get a roof AC unit that mainlines in the 1000's I can be ok. Right now the coleman mach3 I have is not in that range especially in its damaged state.

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Rather frustrating, manufacturers put little in print anymore. There is always 5 pages of do not plug in while sitting in tub or in shower, do not place screwdriver in eye with enough force to cause injury. Then 5 more pages of it in Spanish.

I have been trying to compare AC specs for humidity removal and some do not list it at all. dBA is also something they do not want to advertise! 7 pretty pictures of the remote control but cubic feet minute is hidden somewhere in their website if at all!

Jester

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