I have 16,000 Cruisair system on my Beneteau 361 that has started to overheat. The system runs for 5 minutes and then the compressor overheats and the thermal cutoff on top of the compressor shuts it down. It cools for about 10 minutes and then of course turns on again. When the compressor shuts down the water pump continues to pump and the blower also continues, of course no cool air. I have good water flow and good air flow and no idea what to do.
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Jim Logan
Have you tried these things?
It is possible you have a compressor or thermal switch problem, however, that is rare. It really sounds like a flow restriction in your cooling system - it doesn't take much restriction when the water warms up in the summer and you can't dump as much heat easily - check the screens from your intake first, then pull the hoses off the unit and backflush using pressure water to make sure there are no restrictions - I had mussel shells that had gotten inside my intake at one time and restricted the flow - this will cause this problem. Shutting down like this is what the units do with flow restrictions. Have you tried a new thermal switch? It is possible that a the switch could go bad - how hot does the unit feel when it shuts down - it should be too hot to lay your hand on and leave it, even when running normally - has the paint on the unit turned a color other than white?. A third possiblity is that you are not running your circulating fan speed high enough which will cause the compressor to run hotter, try running the fan speed higher and see if this helps.
It is possible you have a compressor or thermal switch problem, however, that is rare. It really sounds like a flow restriction in your cooling system - it doesn't take much restriction when the water warms up in the summer and you can't dump as much heat easily - check the screens from your intake first, then pull the hoses off the unit and backflush using pressure water to make sure there are no restrictions - I had mussel shells that had gotten inside my intake at one time and restricted the flow - this will cause this problem. Shutting down like this is what the units do with flow restrictions. Have you tried a new thermal switch? It is possible that a the switch could go bad - how hot does the unit feel when it shuts down - it should be too hot to lay your hand on and leave it, even when running normally - has the paint on the unit turned a color other than white?. A third possiblity is that you are not running your circulating fan speed high enough which will cause the compressor to run hotter, try running the fan speed higher and see if this helps.
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Stan Segal
Thanks for the response. Yes I blew out the water lines and cleaned the strainers. The paint on the unit has not turned but when it shuts down, the compressor is very hot to the touch. One thing I didn't try was increasing the air flow because I didn't see the connection. Is the compressor water cooled or air cooled. I know the sea water is what is transeferring the heat.
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Jack
Similar Symptoms
I know this may sound silly, but I must tell you what my problem was when I had VERY similar symptoms with my air conditioner. My problem turned out to be that I had my shore power plugged into the 15 amp service instead of the 30 amp service. Moved to the 30 amp service and problem went away. Jack
I know this may sound silly, but I must tell you what my problem was when I had VERY similar symptoms with my air conditioner. My problem turned out to be that I had my shore power plugged into the 15 amp service instead of the 30 amp service. Moved to the 30 amp service and problem went away. Jack
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O_salt
Check the flow going overboard
To check seawater flow, find your overboard discharge, get a buck and calculate 1-gallon level then time how long it takes you to get to the 1-gallon mark. Your target for a 16K unit is 5 gallons per minute, if you do not get that much flow you have a seawater flow problem. Check everything suggested above, if that doesn't work and you still don't have flow, try cleaning with an acid flush to de-scale the inside of the seawater condensor. If you are getting the right amount of water flow, you have other problems that will probably need the service of a HVAC tech.
To check seawater flow, find your overboard discharge, get a buck and calculate 1-gallon level then time how long it takes you to get to the 1-gallon mark. Your target for a 16K unit is 5 gallons per minute, if you do not get that much flow you have a seawater flow problem. Check everything suggested above, if that doesn't work and you still don't have flow, try cleaning with an acid flush to de-scale the inside of the seawater condensor. If you are getting the right amount of water flow, you have other problems that will probably need the service of a HVAC tech.
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Stan
Air Condtioning problems
I think my next step willl be to run a new length of hose from the sea water pump directly to the compressor. I'll just lay it on the deck and measure the flow. Everything does seem to point to cooling water flow problems but I if I'm not getting sufficient flow I wonder why the system doesn't give me "LOW PRESSURE" error message.
I think my next step willl be to run a new length of hose from the sea water pump directly to the compressor. I'll just lay it on the deck and measure the flow. Everything does seem to point to cooling water flow problems but I if I'm not getting sufficient flow I wonder why the system doesn't give me "LOW PRESSURE" error message.
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O_salt
Low preasure error message
The low preasure error message is for freon preasure not water preasure. Before you change the hose try the water flow test, all you need is a bucket and watch. How quickly are you getting the thermal overload? Do you have access to a amp clamp? Try and get a ampreage reading on what the unit is drawing before it cuts out. The Cruisair units usally have a High Preasure switch that closes when you get to high of head preasure from lack of water flow. The display would show, "HP". O_salt
The low preasure error message is for freon preasure not water preasure. Before you change the hose try the water flow test, all you need is a bucket and watch. How quickly are you getting the thermal overload? Do you have access to a amp clamp? Try and get a ampreage reading on what the unit is drawing before it cuts out. The Cruisair units usally have a High Preasure switch that closes when you get to high of head preasure from lack of water flow. The display would show, "HP". O_salt
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Jim Logan
Stan - Air Conditioner Problems
Stan: 2 things. Go to the Cruiseair site and look for troubleshooting guides - if there are none there, go to the Marine Air Systems site (use google.com) and look at their troubleshooting guides, they will provide a lot of information. MOst of the systems work the same way regardless of the brand. Air flow past the evaporator coils matters because the air flow is what transfers the cooling to the air into the cabin - low air flow means the system will run at a higher head pressure in the compressor, thus more heat - thats why air flow matters.
Stan: 2 things. Go to the Cruiseair site and look for troubleshooting guides - if there are none there, go to the Marine Air Systems site (use google.com) and look at their troubleshooting guides, they will provide a lot of information. MOst of the systems work the same way regardless of the brand. Air flow past the evaporator coils matters because the air flow is what transfers the cooling to the air into the cabin - low air flow means the system will run at a higher head pressure in the compressor, thus more heat - thats why air flow matters.
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dlentz
Low air flow=high head pressure,only in heating
Low air flow only causes high head pressure in the heating mode. High compessor temps are going to be caused by: low water flow thru the condenser. low freon levels. or a bad compressor. ( will be drawning high amps for conditions.)
Low air flow only causes high head pressure in the heating mode. High compessor temps are going to be caused by: low water flow thru the condenser. low freon levels. or a bad compressor. ( will be drawning high amps for conditions.)
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Gord May
dlenz is right
He's absolutely correct - worth repeating. Low air flow=high head pressure,only in heating Submitted by dlentz of San Diego on 07/31 at 07:04AM regarding General_interest "Low air flow only causes high head pressure in the heating mode. High compessor temps are going to be caused by: low water flow thru the condenser. low freon levels. or a bad compressor. ( will be drawning high amps for condit ions.) " Regards, Gord
He's absolutely correct - worth repeating. Low air flow=high head pressure,only in heating Submitted by dlentz of San Diego on 07/31 at 07:04AM regarding General_interest "Low air flow only causes high head pressure in the heating mode. High compessor temps are going to be caused by: low water flow thru the condenser. low freon levels. or a bad compressor. ( will be drawning high amps for condit ions.) " Regards, Gord
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O_salt
Change the overload
Change the over load, their are a couple of things that will cause the overload to go out, either high heat or high amperage. This overload is a bimetal overload after going out a few times the metal gets weaker and will go out sooner. If you have eliminated low voltage and poor water flow, go ahead and replace the overload switch. O_salt
Change the over load, their are a couple of things that will cause the overload to go out, either high heat or high amperage. This overload is a bimetal overload after going out a few times the metal gets weaker and will go out sooner. If you have eliminated low voltage and poor water flow, go ahead and replace the overload switch. O_salt
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BR Cyr
List of possibilities
Usually in any of these A/C systems the high pressure switch will shut down the system before the overload will. It's designed to cut out between 400-425 psi and cut back in at 250 psi. The overload cuts out on temperature at the eqivalent of the noted pressure. A set of pressure gauges and an amp meter should be used to check pressure and amps when the compressor goes off. This will help you diagnose what the possibilities are. Here's what needs to be checked: 1. Pump: Even though the pump is running, that doesn't mean it's pumping to capacity. You need 3 gpm per ton of A/C so you should have at least 4.5 gpm @ 10 feet of head (vertical rise of hose taking into account any elbows used). The impeller should also be checked for wear. 2. Condenser coil: Acid wash the coil using a 5% muratic acid solution in a closed loop until the water flows clear. Be careful and dispose of carefully. Also make sure all hoses are free of sea growth. 3. Compressor: If the amps are high but the pressures are normal, the compressor motor might be going bad. Ohm out the compressor. Measure from common to start, common to run, start to run. Add the first two readings they should be within one ohm of the third reading. Also make sure that the run capacitor is good. A bad run capacitor can make the compressor overheat. Low Pressure: If the pressures are low there won't be enough cooling gas coming back into the suction port to cool off the compressor. It won't go off on low pressure if there's no low pressure switch installed. Hope this information helps, Barry
Usually in any of these A/C systems the high pressure switch will shut down the system before the overload will. It's designed to cut out between 400-425 psi and cut back in at 250 psi. The overload cuts out on temperature at the eqivalent of the noted pressure. A set of pressure gauges and an amp meter should be used to check pressure and amps when the compressor goes off. This will help you diagnose what the possibilities are. Here's what needs to be checked: 1. Pump: Even though the pump is running, that doesn't mean it's pumping to capacity. You need 3 gpm per ton of A/C so you should have at least 4.5 gpm @ 10 feet of head (vertical rise of hose taking into account any elbows used). The impeller should also be checked for wear. 2. Condenser coil: Acid wash the coil using a 5% muratic acid solution in a closed loop until the water flows clear. Be careful and dispose of carefully. Also make sure all hoses are free of sea growth. 3. Compressor: If the amps are high but the pressures are normal, the compressor motor might be going bad. Ohm out the compressor. Measure from common to start, common to run, start to run. Add the first two readings they should be within one ohm of the third reading. Also make sure that the run capacitor is good. A bad run capacitor can make the compressor overheat. Low Pressure: If the pressures are low there won't be enough cooling gas coming back into the suction port to cool off the compressor. It won't go off on low pressure if there's no low pressure switch installed. Hope this information helps, Barry
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Stan
THANKS!!! I have some great trouble shooting ideas I can now try. I'll be heading for the boat next week and will let everyone know how it goes.
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