Premature air conditioner failure

T

ThermalDynamicsSales.com

New Member
Aug 10, 2009
12
Hello everyone,

I'm currently working on a Sea Ray Three Eighty Sundancer with an 18,000 btu CruisAir air conditioner under the forward bunk with the air intake at the foot of the bunk. The boat is only about 2 years old and the compressor has failed. The circuit breaker is tripping.

My question to all the Sea Ray 380 owners is; has anyone had any major problems with their air conditioner? I'm trying to find out if there is an inherent problem with the installation or if this is an isolated incident.

Looking forward to all your replies.

Thank you,
Jerry Staunton-
KeepItCool@ThermalDynamicsSales.com
ThermalDynamicsSales.com
 
Are you sure your not talking about a Sea Ray 38?
They haven't made the 380 since 2004.

I have a 2002 380. I have a 12K BTU Cruisair under the front berth and a 7K BTU in the main cabin. Both are running fine and are original.
 
Thank you for the reply. I'm not sure of the year. The boat looks brand new but could be older then I think. However, on the side of the boat in an italic script font that reads three eighty.

If this helps, the swinging entrance door from the swim platform is in the center of the transom. It is not near the starboard side like In some pictures on this forum.

Jerry-
 
dc380 said:
Are you sure your not talking about a Sea Ray 38?
They haven't made the 380 since 2004.

I have a 2002 380. I have a 12K BTU Cruisair under the front berth and a 7K BTU in the main cabin. Both are running fine and are original.
Click to expand...

Same on my 14 year old boat
 
Thanks to all. I will find out the exact year tomorrow after I call the customer. Glad to hear everyone's Air conditioners are working well.

I will post again when I have the year of the boat.

Jerry-
 
Hello everyone,

All of you that said I was working on a Sea Ray 38 and not a 380 are correct ! After working on so many boats daily I don't always realize what model boat I'm on.

I spoke with the customer and he said it is indeed a 2006 Sea Ray 38. With that in mind, has anyone had trouble with there air conditioner aboard their 38?

It seems like there is enough intake air but I think the air is going directly to the evaporator. It seems like there is little air exchange in the actual compartment thus the compressor might be hotter then usual causing it to fail sooner. A scenario I have seen in the past.

Just a guess. Looking for feedback.

Single Cruisair 18,000 btu air conditioner under forward bunk with air return at foot of bunk. SeaRay38.bunk.jpg

Thanks,
Jerry Staunton-
ThermalDynamicsSales.com


SeaRay38.layout.jpg
 
Since you are considering that "premature failure" might be caused by improper design by Sea Ray, please post better pics.

Your caption of "air conditioner under forward bunk with air return at foot of bunk" doesn't indicate what you think the problem may be. Most typical installations are like this- you want the return air close to the floor....it's where the supply(ies) are located that might be an issue.

Are you saying the unit was "short cycling" by having the supply too close to the return? Isn't the supply in an overhead bulkhead? Please explain further.
 
I agree with Topnpr.

What exactly do you believe is the problem?

Does the unit run at all, or does it blow the curcuit right away?

The couple I travel with has a 2007 Sea Ray 38, and they haven't had any issue with their A/C unit.
 
I'm pretty sure I know the fix. The reason for posting here is to see if any 38 owners have had any problems with their air conditioners. And in posting I hope any boat owner is now aware of the possible scenario below regardless of the boats make or model.

Description of what is happening:

The unit worked flawlessly until the compressor seized. Before it seized it cycled as it should and it cooled the boat nicely. Plenty of air from every discharge grill throughout the boat.

My concern is the compartment itself where the condenser/compressor is located. I don't believe this compartment has any air flow through it. Or to be more specific, no air circulating around the compressor. It seems to be a very air tight compartment. To make matters worse, the thick sound deadening material around the compartment and a mattress on top insulate this compartment.

The blower/evaporator is very close to the air intake grill. So it can't pull any air from the compartment itself. All the air from the intake grill goes directly over the evaporator then through the plenum then ducting and out the discharge grills as it should. However, there is no air exchange in the actual compressor/condenser compartment which would over time cause the compressor's oil to break down from the heat eventually seizing the compressor.

Also, since the compartment seems to be pretty air tight it would have to pull the compartment into a slight vacuum. An additional small intake grill closer to the compressor is what I think the answer is to my dilemma.

Basically, the heat source (being the compressor) has no ventilation to cool itself. An exaggerated example would be covering your compressor making an air tight seal around it. It would eventually fail do to heat. Compressors run hot. But they still need to have air circulation to keep them within tolerable operating temperatures. I have seen this situation before. And before I put a new system in I wanted to see if any other 38 owners had problems. That is my reason for posting here.

So...
Any 38 owners with past or present air conditioner problems?

Thanks,
Jerry Staunton-
ThermalDynamicsSales.com
 
Not sure about this specific boat model and related AC problems but a few thoughts come to mind. Manufacturers state the amount of room required around the unit in the specifications. Have you checked the documentation for your specific type of unit? Might also want to consider putting a thermometer near the compressor to see how high the temps go and then put the thermo in a different boat to gauge the actual variance in temps in the working compartments of the two boats.

Might you be able to drill a 2" hole on each side of the intake grate to allow for air to circulate around the compressor? Cover the holes with a nice vent grate of some sort.
 
Yes, all very good points.

The only manufacturers requirements for space is in regards to the evaporator. If the evaporator is not facing the return air grill and it's facing a bulkhead or some other obstruction there must be a minimum of 3 inches of clearance in front of the evaporator for enough air flow to pass through the evaporator. Their really should be space requirements for the complete system but then that would be difficult to achieve on a boat. Many of these air conditioners are crammed into the only space they will fit. And no one considers heat rejection of the compressor and components.

Getting an accurate temp reading is difficult. I would need to use a remote thermometer that can read higher temperature ranges. It would also need to record the data because to get an accurate reading I need to close the compartment and put the mattress back in place. Or have a remote readout with the sensor in the compartment. I have something similar but doesn't go above 125 since I purchased it for refrigeration not air conditioning. But this could be done with the right instrument. And it would at least give me a point of reference.


I like your 2 inch holes idea. If I can get them in the right spot I will consider that.

Thank you for your reply,
Jerry-
 
In the Sea Ray 380, the forward A/C air intake is on the left side of the berth, and draws the intake air across the A/C unit. So that unit is cooled.

The second unit howerver, is under the sofa, and the only air is through the intake, and that goes directly into the evaporator. No air is circulated around or across the condensor. It's a smaller unit, 7K BTU and not a 18K BTU. but it's the same situation as on the 38.

So I would open up the question to those with SR 38 and 380.
 
I am not an AC expert but isn't the raw water used to cool the heated refrigerant? BTW np problems with our AC. It runs 24/7 in the dehumidify mode and in the normal AC mode when we are on the boat.
 
dc380,

If the evaporator is far enough from the intake then there should be some air turbulence around the rest of the machine and you might be just fine. This is the case for most marine air conditioners installed. It is when the evaporator is so close to the intake grill that there is no turbulent air around the rest of the unit that can cause a problem. This goes for any size unit in a small space. Even a 7k unit can heat up a small space if its a tight fit.

Unfortunately I don't remember the configuration on the 380 (and honestly after 20 years in the business they all start to look alike) but if there is a way to inconspicuously place a grill or opening somewhere it's more then likely worth it if there is no subsequent turbulence. Try to get a rough temperature reading with the compartment area closed and running after a few hours. Ideally you would want room temperature in the compartment but that is impossible on a boat. Other factors are if the unit is up against the hull above the water line it will be warmer and against the hull below the water line will be cooler.

The other thing to note is the cooler the compressor runs, the longer it will last, the current draw will be less and it will perform more efficiently. This is such an important factor. A correctly installed unit should give 20 years of service. Inversely, even if it's only running a little hotter then it should, it may last 18 years instead of 20. So there is a longevity factor.


Hope this helps,
Jerry-
 
mawyatt,

Glad to hear your air conditioner is running good. I'm also glad your running 24/7. This is important. Keeping the boat dry helps prevent mold and mildew which inherently causes odors and eventually wood rot. I tell all my customers to run them in regular mode but a warmer setting when there not there to maximizes dehumidifying. Especially if there not paying for electricity. And if they are on the electric meter then I suggest just the dehumidify mode when there not there. But running in dehumidify mode when your not there is the next best thing to do.

You are correct. The raw water cooling cools the refrigerant. But that is all it does. It doesn't cool the compressor or the electrical box or the reversing valve etc... So surrounding air flow is still needed.

Jerry-
 
Jerry,

On the 38DA the air intake is along the bottom of the forward berth center. The air comes up from the floor on to the AC unit. The filter is a plastic screen on the front of the AC. Around the AC unit is plenty of room including a platform for the fresh water pump. Access is from the top under the matteres with a large cover plate. Looks like SR made this area easy to work, with good work room space. The inlet temp sensor is located just in front of the filter on a wire that is tied off. Some have recommended untieing this and placing the temp sensor outside the AC compartment. I haven't done this because the AC seems to work OK and the only benefit I can see is a better reading of the cabin temp.
 
Mine runs 24/7 during the warm months....78 degrees when I'm not there, and 72 degrees when I am....which is at least 2 days a week. Clean the strainer about 3 times a year. No problems yet.
 
Thank you, yes I have noticed all that you mentioned. However the compartment has no air flow over the compressor. Even though there is a fair amount of work space it is still basically an insulated box. The air intake is sufficient and does supply plenty of air directly to the evaporator. With the larger space I think that's why it lasted 3 years. My fix is going to be to put a small grill above the pump to allow the evaporator to pull air from another direction and over the compressor to the evaporator for some cross ventilation to keep the compressor cooler and prevent dead air space. I'm going to mount the electrical box directly on top of the evaporator (where the serial numbers are) This will keep the electrical box cooler as well. Even the electrical box was hotter then it should be. And that was the second tip off that the compartment was getting too hot even though there is a fair amount of working space around it. If there is space and I think it's necessary, I will move the entire unit away from the grill to help the blower pull some air from the second small grill.





The grill will be small and unless your hanging upside down over the side of the bunk no one will see it.

I'm headed to the boat today and probably take some pictures for others following this thread.

The installation seems to be straight forward and never gave it a second thought until the compressor started failing. Then I realized it had thick sound deadening material on the inside and rug around the outside along with a thick mattress on top and heat was building up enough in the compartment to cause a problem. As far as I can see there is no other openings or gaps to draw positive air flow over the compressor specifically.


Thank you for your reply. Glad your air conditioner is working well.

Jerry-
 
Southpaw II

Those are the exact settings I recommend to my customers. It won't run much at 78 yet do more dehumidifying then the dehumidify setting. And 72 when your there is a comfortable setting.

The good thing about running in normal mode at 78 is that when you arrive and lower it to 72, the air temp only has to drop 6 degrees. And that is manageable for these units. On some boats the owner boards and its 90 inside and then takes all weekend to remove the heat from the boat. That is when I get called and the complaint is always "the units aren't working."

Glad there working well,
Jerry-
 
You must log in or register to reply here.

Forum statistics

Threads
113,187
Messages
1,428,227
Members
61,099
Latest member
Lorenzo512
Back
Top