We have/had a 15 year old AC/DC Norcold 40W refrigeration unit (L-shaped evaporator) which up until this last week has served us well. This Sunday, after a long weekend trip the unit decided to go south, permanently (compressor motor groan, high heat, tripped breaker). At least it waited until we were back at the dock ready to load up and go home! We have an 8 cubic foot top loading box, moderate (4" nominal?) insulation, and an adequate (1" wide) seal on the lid. The 'old' unit (installed by the original owner) was supposed to cool a box of 6 cubic feet, but managed to keep our 8 cubic unit at 38-40F at a cost of 68 -72Ahrs per day at 85F ambient. Run current was 5.7A (thanks, Link 2000R). The question is… Should we go with the small evaporator ColdMachine, which from specs seems to require 5A run current or the larger unit, which requires 5.5A? I would assume that the smaller unit would work out fine, but would hate to have regrets after the fact! With the small amount of $ between the two units, I am considering the larger model with the assumption that run time will be reduced and overall efficiency will be quite similar. It is very important to me to improve, or at the very minimum, maintain our current Ahr consumption. Am I missing something? We leave the refrigeration running continuously during the 6 months the boat is in the water. I guess I will have to buy a small 12V supply or charger to run the unit on shorepower (house bank is disconnected when we leave the boat to protect against a power failure leading to possible discharge of bank). I plan on connecting the supply's output to one side of a DPDT relay which is energized by 110VAC so that it is 'out of the loop' when I'm charging the main bank with my 3-stage 100A charger and is similarly disconnected from the 12V system when shore power is not available and the main bank and/or alternator is supplying power to the refr. Is there a unit you recommend? With start-up surge taken into account, what size supply should I require? One additional item. I installed a 'mixer' fan in the box shortly after we purchased the boat to better distribute the air within. I have the fan wired to a switch which energizes it on when the lid is closed (didn't want it to blow cold air out when the top was open). Takes 0.1A to run and seemed to accomplish the task of keeping food evenly cool throughout the box and reduce Ahr consumption over-all. Any thoughts on this technique? I look forward to your reply! Jeff Jones Escapade
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bill walton
holding plate design
Have you considered a holding plate tyoe system. I'm told that these create less of a drain on batteries because they freeze up whenever a charging source is available and only draw from the battery when they "thaw out" and there's no other source.
Have you considered a holding plate tyoe system. I'm told that these create less of a drain on batteries because they freeze up whenever a charging source is available and only draw from the battery when they "thaw out" and there's no other source.
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Bill Thomas
Size selection
In most cases, when the box size is borderline between the small or large unit, it is best to go with the larger if it will fit in the box. You will want to use a battery charger with a battery for the additional power source. Using a suppy or charger hooked directly to the machine can damage the electronics. The battery will act as a buffer for any stray ac ripple coming through the charging device. We often recommend a small fan in the icebox to help circulate the air and eliminate warm spots. The switch is an excellant idea!
In most cases, when the box size is borderline between the small or large unit, it is best to go with the larger if it will fit in the box. You will want to use a battery charger with a battery for the additional power source. Using a suppy or charger hooked directly to the machine can damage the electronics. The battery will act as a buffer for any stray ac ripple coming through the charging device. We often recommend a small fan in the icebox to help circulate the air and eliminate warm spots. The switch is an excellant idea!
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Jeff jones
Sorry Bill, and...
Sorry about the wrong name Bill, I quickly read the moderators name, Phil, and just assumed. Thanks for the input, but I have a real issue with adding another small battery to 'buffer' the new small power supply! Currently I have 500Ahr house bank and a starting battery. A Link 2500 charges the house and an echo charger services the starting battery. I will not connect the frig directly to the house so as to avoid flattening the bank in case of a prolonged AC power outage (over 4 days). The boat came to me with the refer wired directly to the house bank and within the first month a power outage (someone knocked shorepower cable out) flattened the 'old' house bank. One more battery, charger, and the associated space and weight seem a bit much! My old Norcold switched automatically between 110VAC and 12VDC. This allowed me to simply turn off DC power when leaving. The worst thing that would happen in the event of a power failure would be a loss of refrig contents. Surely someone must have found a less intrusive way around this. Perhaps a N.O. relay connecting the frig to the house bank which is closed by 110VAC, therefore protecting the main bank from discharge during an outage. Just thinking aloud, I don't like not being able to dissconnect ALL loads with the batt. switch. Anyone have a better solution? Jeff Jones Escapade
Sorry about the wrong name Bill, I quickly read the moderators name, Phil, and just assumed. Thanks for the input, but I have a real issue with adding another small battery to 'buffer' the new small power supply! Currently I have 500Ahr house bank and a starting battery. A Link 2500 charges the house and an echo charger services the starting battery. I will not connect the frig directly to the house so as to avoid flattening the bank in case of a prolonged AC power outage (over 4 days). The boat came to me with the refer wired directly to the house bank and within the first month a power outage (someone knocked shorepower cable out) flattened the 'old' house bank. One more battery, charger, and the associated space and weight seem a bit much! My old Norcold switched automatically between 110VAC and 12VDC. This allowed me to simply turn off DC power when leaving. The worst thing that would happen in the event of a power failure would be a loss of refrig contents. Surely someone must have found a less intrusive way around this. Perhaps a N.O. relay connecting the frig to the house bank which is closed by 110VAC, therefore protecting the main bank from discharge during an outage. Just thinking aloud, I don't like not being able to dissconnect ALL loads with the batt. switch. Anyone have a better solution? Jeff Jones Escapade
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Bill Thomas
battery protection
The system will automatically cut out at 10.5 volts(nominal). It should not flatten the bank. We do have a device available that is a true AC to DC converter. You will also need a DC to DC converter, which we also have. The 1st converter steps Ac to 27 VDC. The second device steps 27 to 12 VDC. Where are you located? I can give you the name of a supplier.
The system will automatically cut out at 10.5 volts(nominal). It should not flatten the bank. We do have a device available that is a true AC to DC converter. You will also need a DC to DC converter, which we also have. The 1st converter steps Ac to 27 VDC. The second device steps 27 to 12 VDC. Where are you located? I can give you the name of a supplier.
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Dave Dahlstrom
Small or Large ColdMachine Question
Take a look at the NovaKool System. It's a little cheaper and has a better BTU rating while using about the same amperage.
Take a look at the NovaKool System. It's a little cheaper and has a better BTU rating while using about the same amperage.
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Bill Thomas
NovaKool
The Adler/Barbour product range has BTU ratings of 484 to 591. This is because we use the new BD5.0 compressor which is a higher rating than the BD3.5. (NovaKool) This compressor draws about another amp, but the run time is reduced drastically. To get an increase in BTU's, there must be an increase in amps. This is a physical law, unchangable, like ohms law. btu=wattsso higher btu's=higher watts=higher amps. What is NovaKool specing for current draw? Always remember, Capacity, efficiency and Amps are NOT constant. They change continuously as system starts up at high temp and pulls down to its low temp cutoff.
The Adler/Barbour product range has BTU ratings of 484 to 591. This is because we use the new BD5.0 compressor which is a higher rating than the BD3.5. (NovaKool) This compressor draws about another amp, but the run time is reduced drastically. To get an increase in BTU's, there must be an increase in amps. This is a physical law, unchangable, like ohms law. btu=wattsso higher btu's=higher watts=higher amps. What is NovaKool specing for current draw? Always remember, Capacity, efficiency and Amps are NOT constant. They change continuously as system starts up at high temp and pulls down to its low temp cutoff.
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Jeff Jones
Converters and such
Bill, we are in SE Michigan. Yes, the low voltage cutoff on your units would provide protection. How reliable is this cutoff point? How reliable is the cutout? There must be some loading even when the low voltage protection is 'active'. Any idea how much? I am starting to wane on wiring the unit directly to my house batteries, but still prefer my current ability to totally shut off all DC equipment when I leave the boat at the battery switch. An AC to DC converter and a DC/DC step down? Do these units would provide any loading when off shorepower and under battery power. Hopefully the local suppliers will have this info! Getting closer Bill. Thanks again, Jeff Jones Escapade
Bill, we are in SE Michigan. Yes, the low voltage cutoff on your units would provide protection. How reliable is this cutoff point? How reliable is the cutout? There must be some loading even when the low voltage protection is 'active'. Any idea how much? I am starting to wane on wiring the unit directly to my house batteries, but still prefer my current ability to totally shut off all DC equipment when I leave the boat at the battery switch. An AC to DC converter and a DC/DC step down? Do these units would provide any loading when off shorepower and under battery power. Hopefully the local suppliers will have this info! Getting closer Bill. Thanks again, Jeff Jones Escapade
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Jeff Jones
Holding plates
Thanks for your input Bill (Walton). The debate between a holding plate and an evaporator was pretty much over when my wife found out we could maintain or make ice, and perhaps even keep ice cream aboard! I have to admit that I was swayed by this too. I realize that we could compartmentalize our existing box with a cold plate (refer and freezer), but we really don't have the proper box configuration for this and the reduction in refrigeration space would become an issue for us too. A 0.4 to 0.6 C ft. freezer would be just about right! Jeff Jones Escapade
Thanks for your input Bill (Walton). The debate between a holding plate and an evaporator was pretty much over when my wife found out we could maintain or make ice, and perhaps even keep ice cream aboard! I have to admit that I was swayed by this too. I realize that we could compartmentalize our existing box with a cold plate (refer and freezer), but we really don't have the proper box configuration for this and the reduction in refrigeration space would become an issue for us too. A 0.4 to 0.6 C ft. freezer would be just about right! Jeff Jones Escapade
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Bill Thomas
RE: converters and such
I am not sure what you mean by loading. The converter will sense when AC power is available and run the unit off AC power. As soon as you unplug, it will automatically switch over to DC power
I am not sure what you mean by loading. The converter will sense when AC power is available and run the unit off AC power. As soon as you unplug, it will automatically switch over to DC power
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Jeff jones
Loading
By loading, I am speaking of the DC load, perhaps in the area of milliamps, that the back side of the converter may put on the 12VDC line into the refer unit. To put it another way, the output of the converter has some impedance, even when turned off (no AC source) which relates to some load on the main DC bank. You were going to provide me with the local contact for the converter and step-down transformer. Do you have one in SE Michigan? Thanks. Jeff Jones Escapade
By loading, I am speaking of the DC load, perhaps in the area of milliamps, that the back side of the converter may put on the 12VDC line into the refer unit. To put it another way, the output of the converter has some impedance, even when turned off (no AC source) which relates to some load on the main DC bank. You were going to provide me with the local contact for the converter and step-down transformer. Do you have one in SE Michigan? Thanks. Jeff Jones Escapade
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Jeff jones
Compressor type?
Do you use the BD50F for both the smaller and larger vertical ColdMachines? If so, is your electronic unit the unit supplied to you with the compressor (if so, I found the specs I was after). Do you run the compressor at the standard 2000RPM or faster? Jeff Jones Escapade
Do you use the BD50F for both the smaller and larger vertical ColdMachines? If so, is your electronic unit the unit supplied to you with the compressor (if so, I found the specs I was after). Do you run the compressor at the standard 2000RPM or faster? Jeff Jones Escapade
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Bill Thomas
RE: LOADING
The relay in the unit opens completely allowing 0 current to flow when the unit is off. The part numbers are MPS-50 and t804k. However, your idea of a switching relay will also work if you are cocerned with having your house bank on line at all times. Th contact in SE MI is J&S Marine (810)463-3400
The relay in the unit opens completely allowing 0 current to flow when the unit is off. The part numbers are MPS-50 and t804k. However, your idea of a switching relay will also work if you are cocerned with having your house bank on line at all times. Th contact in SE MI is J&S Marine (810)463-3400
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Bill Thomas
re: compressor type
We use the BD50 on all models. Also, the correct electronics that are supplied with the compressor are used. The compressor is run at varying speeds depending on the application.(slower for small evaps and faster for the large evaps.)
We use the BD50 on all models. Also, the correct electronics that are supplied with the compressor are used. The compressor is run at varying speeds depending on the application.(slower for small evaps and faster for the large evaps.)
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Jeff jones
Thank you Bill
Thanks for the local supplier's name. Believe it or not, I think I may be out of questions. Thank you very much for your assistance! Now all that remains is a trip to the boat to determine if the larger evaporator would work from an access standpoint, or if the .4cu.ft. unit would work best. By the way, in every single catalog (E&B, Boat, etc.) and web site I visited (except this forum, of course) a 6v charger was specifically recommended for running the units from shore power (no mention of a buffer battery, i.e. capacitor). I understand and agree with your recommendation not to do this, but am surprised at the overwhelming mis-information regarding this application! Jeff Jones Escapade
Thanks for the local supplier's name. Believe it or not, I think I may be out of questions. Thank you very much for your assistance! Now all that remains is a trip to the boat to determine if the larger evaporator would work from an access standpoint, or if the .4cu.ft. unit would work best. By the way, in every single catalog (E&B, Boat, etc.) and web site I visited (except this forum, of course) a 6v charger was specifically recommended for running the units from shore power (no mention of a buffer battery, i.e. capacitor). I understand and agree with your recommendation not to do this, but am surprised at the overwhelming mis-information regarding this application! Jeff Jones Escapade
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Jeff Jones
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