This weekend I measured the actual power draw on
our Cool Mate CLM12K (12,000 BTU) air conditioner
and found that it was drawing 12 amps at 124V AC
instead of the 9.1 amps claimed on the Dometic
website.

http://www.marineair.com/pdfs/L-2124.pdf

Is there something wrong with my unit, or is it
just a case of "specmanship". I'm wondering if
the spec sheet power may be for the unit itself
without the necessary sea water pump running.

12 amps is 33% higher than the spec.

Anyone know?

Don W.

Don W wrote in news:m_6xg.134232
:


This weekend I measured the actual power draw on
our Cool Mate CLM12K (12,000 BTU) air conditioner
and found that it was drawing 12 amps at 124V AC
instead of the 9.1 amps claimed on the Dometic
website.


How much it draws is heavily dependent on its condensor temperature,
which changes the pressure the compressor has to work against. Monitor
its current and let it stabilize at 12A. Spray some water into the side
of the case so the fan can suck it into the condensor and watch the load
ease on the compressor.

The unit will probably draw less current after it has been running a few
hours so the case fills up with condensate water. There is a slinger
ring around the fan that blows through the hot condensor. This ring
picks up water from the pan it's built on and throws it up in the airflow
to the condensor, water cooling it with distilled condensate water from
the evaporator, exactly like a $99 cheap window air conditioner, which is
what the coolmate really is. Once the water supply has been condensed
and run outside into the slinger, it'll cool the condensor much better,
dropping your current drain.

It's also drawing more current because you're applying more voltage to
the unit than it was designed for, which doesn't really hurt it. The
plate probably says 115VAC, not 124VAC you measured.

If you're thinking about driving it with a generator or inverter, plan on
providing it with TWICE the running current drain, 24A AC, so you can
START it. It draws a LOT of current for a couple of seconds when it
starts. The genset must provide this starting power (the peak rating on
the genset) without tripping out or sagging voltage too far. A 3KW
genset is about right for this unit....but not a 1500W. I'm pulling TWO
8000 Btu LG Electronics Korean window units to cool my stepvan shop.
There's also a 2.7 cu ft R-12 fridge that starts all at the same time off
a Honda EU3000i electronic inverter superquiet genset mounted permanently
on the back. If it'll pull that load, it'd be great for your unit.

Now, put all that test equipment away, get a cold alcoholic beverage out
of the cooler and go sit in front of the Coolmate before you get a notion
to take the cabinet off to see what's wrong and screw it all up!

Larry wrote:
Don W wrote in news:m_6xg.134232
This weekend I measured the actual power draw on
our Cool Mate CLM12K (12,000 BTU) air conditioner
and found that it was drawing 12 amps at 124V AC
instead of the 9.1 amps claimed on the Dometic
website.

How much it draws is heavily dependent on its condensor temperature,
which changes the pressure the compressor has to work against. Monitor
its current and let it stabilize at 12A. Spray some water into the side
of the case so the fan can suck it into the condensor and watch the load
ease on the compressor.

The unit will probably draw less current after it has been running a few
hours so the case fills up with condensate water. There is a slinger
ring around the fan that blows through the hot condensor. This ring
picks up water from the pan it's built on and throws it up in the airflow
to the condensor, water cooling it with distilled condensate water from
the evaporator, exactly like a $99 cheap window air conditioner, which is
what the coolmate really is. Once the water supply has been condensed
and run outside into the slinger, it'll cool the condensor much better,
dropping your current drain.

Well, the only problem with this theory is that
the condensor is raw water (sea water in this
case) cooled. The cooling water comes from a
seawater pump attached to a thru-hull.

It's also drawing more current because you're applying more voltage to
the unit than it was designed for, which doesn't really hurt it. The
plate probably says 115VAC, not 124VAC you measured.

True. I considered that, but the current draw is
33% higher, and 9V out of 115V is only about 8% or so.

good advice snipped

Now, put all that test equipment away, get a cold alcoholic beverage out
of the cooler and go sit in front of the Coolmate before you get a notion
to take the cabinet off to see what's wrong and screw it all up!

;-) Actually, I'm considering doing something
worse, which is relocating the unit to somewhere
else in the boat. Right now, its completely
taking up the only closet that has any hang-up
space in the rear cabin :-(

Don W.

Don W wrote in news:LYexg.11933
:

;-) Actually, I'm considering doing something
worse, which is relocating the unit to somewhere
else in the boat. Right now, its completely
taking up the only closet that has any hang-up
space in the rear cabin :-(

D

Hmm....I'm not very "nautical". Tugboats and other commercial vessels
did what I think is the right thing....scrap all this marine crap and put
a Coleman RV rooftop AC on top of that leaky hatch over the main salon
with the louvers pointed fore and aft. To hide it from the purists, have
the canvas shop make you a Ships Wheel Cover or one with nautical-looking
logos or flags or knots. It does make a dandy deck seat if the boom
isn't swinging. Tell the curious it's the "safety box" on deck after you
hide the Coleman logo in canvas...(c;

I talked a fellow in a nice catamaran into scrapping his crappy, always
clogged with something, marine AC and putting a Coleman on each pontoon.
They like to froze to death because they had the thermostat too cool..(c;

Rooftop air units have all the "heat loads" OUTSIDE the boat, not in the
closet with the intake heating up and eating your Btus. Once you get the
hot compressor, hot seawater evaporator and hot fan motor OUT of the air
conditioned space, it takes a few thousand LESS Btu to cool the boat! I
also like the RV units with "Easy Start" kits in them. INstead of that
huge starting current blinking the lights, Easy Start units SLOWLY start
the compressor, using no more power to start the compressor than to run
it. No surge current, you can use a lot smaller genset to power it.

Ok, this commercial is over. Just look at your current installation and
see how many lockers, cupboards, storage spaces you'd regain hauling out
all those nasty hoses, ducts, the unit itself.

Oh, I forgot to mention the rooftop AC is 1/10th the NOISE inside the
boat while you're sleeping!

Larry wrote:

Don W wrote in news:LYexg.11933
:


Well, the only problem with this theory is that
the condensor is raw water (sea water in this
case) cooled. The cooling water comes from a
seawater pump attached to a thru-hull.

Oh, sorry, I must have been thinking CarryCool, the portable one. Ignore
the rest of my post.

How hot does the seawater condensor feel? Can you hang onto it,
comfortably? Now it sounds like low cooling water capacity/clogged
strainers-hoses-condensor-outlet problems. The problem remains the
same....too much backpressure on the compressor, which usually means high
head pressure from too little flow on water-cooled condensors.

I need to check the water flow. It has been
flowing just fine, but it has been a few weeks
since I specifically checked it.

The unit is installed in the closet with the
evaporator right behind the door. The door has
the typical louver slots in it which lets the
return air into the unit. The problem is that it
is next to impossible to get to the back side of
the unit due to space restrictions, so I have no
idea how hot the condenser is running.

Do you have a set of refridgeration guages? We need to see those
pressures to assess pressure problems. You could also have clogged
capillary tubes feeding the evaporator from a dirty system. Gotta get
some guages on them and you'll need a probe thermometer we can stick into
the evaporator core, one of those little pocket ones AC people keep in
their pockets.

I do have a set of R12/R22 gauges as well as a new
set of R134A gauges. Since the unit is R22 based,
I guess I could hook up the gauges and read the
condenser temperature off of the high pressure
gauge. Maybe I'll do that next time I go down to
the boat.

I think I'll also contact Cool Mate, and find out
what the current draw should be with the sea water
pump running.

If the condensor is hot, the pressure really stalls the compressor
raising the current you're measuring. The damned cheap seawater pumps
that feed these units are crap. They don't prime themselves and if the
boat heels over with the thru-hull valve left open, they'll get air in
them, maybe not enough to go completely dry, but enough to make flow just
awful. What I've done to a few of them is to put a T on the seawater
pump outlet, one to the condensor to cool the AC and the other to just an
open-ended valve I can flip open to let the air out of the pump so it'll
fully prime and let the bubbles out.

The damned strainers sold for these things is way too fine! Any creepy
crawlers that can pass through the condensor on the AC SHOULDN'T be
filtered out by the strainers...clogging them in a week, here. I've
changed out the strainers to ones with perforated metal sleeves, instead
of those fine screens. If it sucks up something big, it stops it. If it
sucks up a little crawler, it feeds him through the system and pours his
partially cooked guts over the side, making the crabbing under the boat
improved...(c;

Is lots of water pouring out of the boat outlet and the seawater
condensor cool enough to hang onto?.....

Well, there was a lot of sea water pouring out of
the outlet last time I checked, but that has been
a month or so ago, and before I measured the
current. Its a good thought to check the flow,
and see if that is why the current is high.

Don W.

Larry wrote:

Don W wrote in news:LYexg.11933
:


;-) Actually, I'm considering doing something
worse, which is relocating the unit to somewhere
else in the boat. Right now, its completely
taking up the only closet that has any hang-up
space in the rear cabin :-(

D


Hmm....I'm not very "nautical". Tugboats and other commercial vessels
did what I think is the right thing....scrap all this marine crap and put
a Coleman RV rooftop AC on top of that leaky hatch over the main salon
with the louvers pointed fore and aft. To hide it from the purists, have
the canvas shop make you a Ships Wheel Cover or one with nautical-looking
logos or flags or knots. It does make a dandy deck seat if the boom
isn't swinging. Tell the curious it's the "safety box" on deck after you
hide the Coleman logo in canvas...(c;

I talked a fellow in a nice catamaran into scrapping his crappy, always
clogged with something, marine AC and putting a Coleman on each pontoon.
They like to froze to death because they had the thermostat too cool..(c;

Rooftop air units have all the "heat loads" OUTSIDE the boat, not in the
closet with the intake heating up and eating your Btus. Once you get the
hot compressor, hot seawater evaporator and hot fan motor OUT of the air
conditioned space, it takes a few thousand LESS Btu to cool the boat! I
also like the RV units with "Easy Start" kits in them. INstead of that
huge starting current blinking the lights, Easy Start units SLOWLY start
the compressor, using no more power to start the compressor than to run
it. No surge current, you can use a lot smaller genset to power it.

Ok, this commercial is over. Just look at your current installation and
see how many lockers, cupboards, storage spaces you'd regain hauling out
all those nasty hoses, ducts, the unit itself.

Oh, I forgot to mention the rooftop AC is 1/10th the NOISE inside the
boat while you're sleeping!

Yep, I've considered replacing this AC with an RV
unit, and may yet do just that. The only place I
could put it would be over the hatch in the
V-Berth. We'll see...

Don W.

Don W wrote in news:6Dpxg.179658$F_
:

Maybe I'll do that next time I go down to
the boat.

Is it running now? "Next time I go down to the boat" might be after the
compressor has locked, too late.

They run all the time around here. It keeps the boat ready for occupancy,
the electric is included with the awful slip rent, and the boat smells lots
fresher all dried out with the AC running.......its strainer filled with
marine life dating back to before the dinosaurs roamed the Earth.

Little buggers bite like hell, too! Stuck in the strainers, they are in no
mood to compromise....(c;

No its not running. We turn everything except for
the bilge pump off when we leave.

Don W.

Larry wrote:

Don W wrote in news:6Dpxg.179658$F_
:


Maybe I'll do that next time I go down to
the boat.


Is it running now? "Next time I go down to the boat" might be after the
compressor has locked, too late.

They run all the time around here. It keeps the boat ready for occupancy,
the electric is included with the awful slip rent, and the boat smells lots
fresher all dried out with the AC running.......its strainer filled with
marine life dating back to before the dinosaurs roamed the Earth.

Little buggers bite like hell, too! Stuck in the strainers, they are in no
mood to compromise....(c;