Current draw of Coleman Polar Cub air conditioner

thataway

We have been using the Coleman Polar cub RV type roof airconditioner for about 2 months now. Even in temperature up to 105 ambient, it has provided aequate relief from the heat. Yesterday two new Tom Cat 255 owners visited and we began to discuss the current draw (They were impressed with the cooling).

We have a "Kill-a-watt" meter--usually about $50, but as low as $30 on the internet. This meter measures voltage, amp draw, watts, hz and cummulative current used. We used the cord I use with the Honda EU 2000i alternator/inverter "generator" to measure current use on the boat.

We had a Guest 5/5 battery charger (factory), True Charge 20/20 charger on for the entire test (since this is the way that the boat will probably be running)--The chargers, both in trickle mode--used 1.8 amps. It is most likely that at full capacity they will draw more--maybe up to 5 amps max.
We added the air conditioner--first low fan: 2.3 amps (increase of 0.5 amps over the charger), high fan, 2.8 at start up, but settled down to 2.3 (not sure why). Low cool 8.87 max cold start with the AC off for 14 hours, and running draw 6.0 amps (or 5.2 if you subtract the charger--I may decide to re-do the study with both discharged batteries and with the chargers off).
High air conditioner:6.5 amps running or 5.7 air conditioner along. This is most encouraging and confirms why the Honda EU2000i will run the airconditioner in eco mode. In fact from these numbers it is quite possiable that the Honda will run the air conditioner plus a 600 watt microwave--of course it will not run the water heater with the air-conditioner.

Casey · Posted: Tue Sep 26, 2006 10:29 am Post subject:

Very interesting data Bob, thanks.

It's even better considering the fact that your data was collected with the EU2000 in "eco" mode. That leaves the option of turning off the eco mode and going for "full power" if one felt it was necessary (doesn't sound like it will be necessary.

You're becoming a bit of an R&D test-bed for various options and improvements! Like your aproach and your thoroughness; again Thanks!

Casey
C-Dory Naknek

Sea Wolf · Posted: Tue Sep 26, 2006 12:41 pm Post subject:

Actually,

with a start up amperage of 8.87-1.8 (charger) = ~7 amps, = 840 watts @ 120v,

and a running amperage of 5.7 amps, = 684 watts @ 120 v,

one could run the Polar Cub with a Honda 1000i generator, although it would be working it a bit!

Bob- Did I read your figures correctly?

Joe.

thataway · Posted: Tue Sep 26, 2006 12:51 pm Post subject:

Joe, it might be possiable--but the rated max output of the Honda EU1000i is 8.3 amps and running load is 7.5 amps sustained. This would be on full power. Would the 1000 start the Polar Cub?--possiably but it would be a strain. One could not run anything else.

To clarify the measurements were on mains current 121.9 volts 60 hz. I have run the Coleman Polar cub with the Honda EU2000i, in eco mode, but the tests were using mains power. I'll have to check the draw using the generator next time I fire it up. I have used the "Kill a watt" and it seems to work fine. The people who have put scopes on the Honda says it gives very clean power.

If the voltage drops, the amperage goes up--and that may be a problem with a smaller generator--not sure how the Honda inverter handles that.
I have not overloaded the generator to find out! Many inverters will handle a transcient overload.

thanks for the questions and comments. Maybe I should start a column called "Practical C Dory". :teeth

Sea Wolf · Posted: Tue Sep 26, 2006 2:02 pm Post subject:

Bob-

Thanks for the response!

I know iit would be a stretch on the 1000i, but might work on a CD-22 on low cool setting once the cabin was cooled down, depending on the climate.

Start-up would still be an issue, but no way to know w/o trying!

Yep- "Bob's C-Dory Practical Answers, Advice, and Rx"... or is that too much like non-retirement?

Joe.

mikeporterinmd

thataway · Posted: Wed Sep 27, 2006 12:12 am Post subject:

Mike,
I have seen a similar unit on a C Dory 25. The Corp of engineers uses them on 22 foot pilot house aluminum boats. There is no reason that you could not put one--but there is more room on the cabin top in the 25 and TC. Also these weigh about 90 lbs. Might make the 22 slightly more tender, since the waterline beam is narrower. Also the TC has a bit higher roof. I was 6'2" and still have headroom under the AC unit (even with the 1/2" frame I built of wood to follow the contour of the roof on the inside.

Best Day · Posted: Sun Jun 22, 2008 2:03 pm Post subject:

Thataway, this is very interesting numbers you have posted. I am going to the sea of cortez in August so I'm considering adding an AC to my 23cc. It looks like from the numbers you have posted that a Honda 1000 would run this AC unit. Have you ever tried running it on a 1000? It looks like if the AC were started on low cool and then once running put on high cool the 1000 would be able to handle it.

I have a Honda 1000 and would like to find something roof mounted that will work.

Bill

Sea Wolf · Posted: Sun Jun 22, 2008 3:38 pm Post subject:

Bill-

Wanderer did some experiments on this exact topic within the last two weeks:

1000 watt Generator and 5000 BTU Air Conditioning

Joe. Teeth

marvin4239 · Posted: Sun Jun 22, 2008 3:42 pm Post subject:

Bob your post is perfect timing. I've got my 22 on the trailer and have been installing a sliding tray under the helm seat for a Waeco freezer. I've been toying with installing a roof air and currently have a 5K Walmart AC in the center window so I can work in comfort. Surprising how well this cools the cabin in this 90+ degree heat. Curtains down make a big difference. The only thing that has stopped me from installing the roof air is having to deal with the weight and size of the Honda 2000 (bad back). Sure would be nice to think the 1000 would run the Polar Cub in a pinch. Someone posted about purchasing a Honda knock off from West Marine that was 1250 watt output but I haven't seen any results on how they liked it. I inquired at West Marine about this and as usual they didn't know what I was talking about.

Spike38 · Posted: Mon Jun 23, 2008 6:33 am Post subject:

Even less than 2¢ worth here: No figures such as Thataway is able to cite but a Honda 2000 EU runs the 13.5K unit on our RV just fine in econ mode. The dealer who sold us the RV runs these 13.5K units (and maybe bigger) with a 1000 w generator all the time so surely worth a try. I hear modern A/C units start much more easily than older ones.

I'm interested in the Waeco installation. Way ahead of myself because no boat (yet) but planning's half the fun, right? Which size fits below the helm seat and what have you decided on for the sliders? Thanks.

Wefings · Posted: Mon Jun 23, 2008 8:32 am Post subject:

We use the heat pump Polar Mach 13.5 kBTU unit with the 2000 Honda successfully . You cannot use eco mode however and is working pretty hard but does work .I built a 10 Ga. short cord for the last install , Dont want to bottleneck the amperage available or run 35 feet of extra wire unnecessarily .
Marc

captd · Posted: Mon Jun 23, 2008 10:46 am Post subject:

Have any of you Brat checked the voltage output of the 1000 Honda? At one time I used it to power a Norcold #100 freeze. ( 12 V. or 110 V.ac) I decided to check the voltage. Without a load it was putting out 150 volts. It made me a little nervous so I stopped. My 1000 is 10 to 15 years old, maybe they have a better regulator now? You think? Did the " I " series Hondas fixed that problem?

captd

Sea Wolf · Posted: Mon Jun 23, 2008 10:49 am Post subject:

[quote="Spike38 <Lots of other discussion clipped>

" The dealer who sold us the RV runs these 13.5K units (and maybe bigger) with a 1000 w generator all the time so surely worth a try."

[/quote]

If you read all the discussion on this and other threads, you'll see that the Honda 1000i can run an easy to start 5000 BTU AC unit, and maybe even some slightly larger ones, but that it takes a 2000i unit to run a 13,500 BTU unit.

Just bad information from the dealer.

Joe. Teeth

Best Day · Posted: Mon Jun 23, 2008 12:07 pm Post subject:

Thanks for the feedback guys. I have done a little research and found out a couple of things. First off the Coleman Polar Cub 8300 is supposedly the most efficient rooftop mounted AC available. According to the spec sheet with the AC on the 8300 model draws 7.8 amps with the fan on low and 8.2 amps with the fan on high. The 7.8 amp draw on low is very close to the Honda 1000's rated output of 7.5 amps. So on a good day maybe the 1000 could run it if it could get it started. The problem is that when I will want to run the AC it will be 100 degrees outside and the Honda 1000 would probably overheat running so hard.

These soft start kits that you see for different AC's are just extra capacitors that you can add on to the AC units. The Coleman Polar Cubs come with two rather larger capacitors already installed. This explains why Thataway experienced a drop in amp draw after having the fan on for a while. If you are trying to start a large AC on a smaller generator you should turn the fan on for about 2 minutes to let the capacitors fully charge up before you turn the compressor on. So in theory if your generator will put out enough power to run the compressor of the AC, you can just keep adding on capacitors until they absorb all of the demand created by the compressor cycling on and off.

Now if I could just find an efficient 8000 btu rooftop AC I could probably get it to work.

Bill