Decided to stick an inexpensive 110ac Dorm fridge in the port aft berth. I wanted to be able to keep the fridge running when I'm not on the boat without having to power up the ac panel. Put a small bus bar in the shore power line and ran it to a circuit breaker, which in turn feeds pole 1 of a 1-2-0 switch. Ran another line from a breaker on the ac panel to pole 2 of the switch. The switch feeds a GFCI plug. This way I can keep shore power to the fridge on switch position 1, or on the rare occasions when I want to allow it to run on inverted ac power I use switch position 2 [even the greenest of those fridges will draw down the house bank in no time]. Does this make sense or did I make this far more complicated than necessary?
Dorm Fridge: Too Complicated?
- Thread starter wufibugs
- Start date
Wufi...
Replaced the Origo oven with a 2.5 cu. ft. dorm fridge on my H34 and had no problem, noise or otherwise, with it when staying on the boat. It's AC current draw was only a couple of amps. See pix...
Replaced the Origo oven with a 2.5 cu. ft. dorm fridge on my H34 and had no problem, noise or otherwise, with it when staying on the boat. It's AC current draw was only a couple of amps. See pix...
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So you don't want to power up the panel but power is supplied to it.....?????
I don't really understand what you accomplished by installing a separate CB (presumably) away from the panel except the next owner will be confused.
It would seem to be simpler to just put a CB in a spare slot on the panel and be done with it.
I would agree that it will drain the batts in a short time while away from shore power. batts--> inverter --> reefer verses batts --> reefer
the argument being you can suffer the shore power --> charger --> batts --> reefer losses better as you are on shore power and don't have an electrical production issue.
you can't really argue with success though. Question it sure but can't argue about it if it works.
I don't really understand what you accomplished by installing a separate CB (presumably) away from the panel except the next owner will be confused.
It would seem to be simpler to just put a CB in a spare slot on the panel and be done with it.
I would agree that it will drain the batts in a short time while away from shore power. batts--> inverter --> reefer verses batts --> reefer
the argument being you can suffer the shore power --> charger --> batts --> reefer losses better as you are on shore power and don't have an electrical production issue.
you can't really argue with success though. Question it sure but can't argue about it if it works.
Bill, if I just added a breaker to the ac panel, and energized the main ac breaker for the panel and the "new" reefer breaker, if the shore power failed, wouldn't that signal my inverter to kick in and produce ac power until the batts went dead? That's what I was hoping to avoid by having a dedicated cb protected ac line to the reefer. If the shore power shuts down, I may lose some food, but I would have dc power for the boat. May not be too likely in most domestic slips, but I thought that some marina's might be a little dicier. Your point about confusing is well taken; not sure I can remember how to operate the switches and pretty sure I'd be totally baffled after a few brewskies.
Only if the inverter comes on automatically when shorepower is lost. On my Freedom 15 combined inverter charger, I have to turn on the inverter from the Link 2000 to energize it. I could leave the inverter on and if shorepower is present the built-in auto transfer switch uses the shorepower, but if it failed the inverter would take over.
It all depends on how it's wired and set up.
It all depends on how it's wired and set up.
Like Dan I replaced my H34's oven with a dorm fridge. I put a CB in the AC pannel and ran wire around to the fridge. I run the fridge off just the AC pannel since I do not have a built in inverter just a plug in. The fridge stays cold all day while out sailing with no power so I have never worried about the AC power going out while the boat is at the pier since the fridge will stay colder longer than the power outage will last.
Stu, my old Freedom 20 automatically comes on when it senses the absence of shore power. I didn't realize there was a way to enable/disable that feature. I'll have to read the manual carefully to see how that's done.
The inverter AC in should come from a breaker - either the double main breaker of your panel or another breaker on the panel. If the breaker that feeds the inverter AC in is turned off the inverter cannot come on when shorepower fails or is disconnected.
In a properly wired system, no. An inverter should ideally have: Battery + Terminal > Class T Fuse > ON/OFF Batt Switch > Inverter + DC Terminal.
When you leave the boat simply switch the inverter switch to OFF then it can not auto transfer.... Course you will want another means of charging if you do this.. On many IC's you can physically disable auto-transfer but on the Freedom with basic remote this is not an option. This is one more reason I am not a huge fan of IC's as when you lose shore power, it happens, you draw down the batteries. Even the stand-by loads on many of these is high and over time can draw the batts even with no AC loads.. If you did lose power and the switch was not off then the inverter would shut down low DC voltage. Hopefully when AC power is restored the voltage is not so low that it won't go back into charge mode.
Tapping into the AC feed, before the double pole breaker, is not advisable. To do this correctly it means adding an entire new AC inlet and second AC panel. One inlet is not allowed to feed two on-board services per current accepted safety standards.. If you want to properly have a second power feed for the fridge then you really need a full second on-board AC system; cord set > AC inlet > 10/3 wire feed > AC panel with double pole breaker > branch breakers.
If your inverter is not an "auto-transfer" type then you will need a manual Rotary Switch INVERTER/SHORE switch which properly isolates and transfers.. If you have enough slots in your AC panel you can use an either/or slide lockout system for the two double pole breakers.
To go through all this trouble to then have a huge hunk of sheet metal and foam you really can't use while cruising seems like an effort in tail chasing...
These fridges draw about 13A - 16A when running off an AC inverter. This is double to triple what a good efficient DC system will use....
Not to put too fine a point on it, but that is a big load. A 15Ah load would take down my battery capacity after 6 hours off the shore power. I typically keep my load at half that...and I know I have a genset to fix me at the end of the day; before I switch on the anchor light and switch on the mood lamp.
"Tapping into the AC feed, before the double pole breaker, is not advisable. To do this correctly it means adding an entire new AC inlet and second AC panel. One inlet is not allowed to feed two on-board services per current accepted safety standards.. If you want to properly have a second power feed for the fridge then you really need a full second on-board AC system; cord set > AC inlet > 10/3 wire feed > AC panel with double pole breaker > branch breakers."
I am curious, Maine, as to why an entire second ac feed from the shore source to panel is necessary, particularly if I could have run the reefer off the ac panel. My shore/IC 2000 is set up as you suggest (Battery + Terminal > Class T Fuse > ON/OFF Batt Switch > Inverter + DC Terminal) except I happened to have on hand and used an on/off circuit breaker where you suggest a Batt switch. BTW, if I did that more or less correctly it was, I'm sure, completely inadvertent.
The ac wiring from shore is probably 10/3 as is the shore power cord I suspect. But everything from the new bus > breaker > 0-1-2 switch > plug, and bus > ac panel breaker > 0-1-2 switch > plug, is 8/4 because I already had the wire.
As you point out, any effort to manually stop the 2000 from automatically switching to inverted ac power, will also disable the charger. I don't really contemplate using the reefer on inverted power, particularly on anything more than a 2 day sail. As others have pointed out, apparently they will stay cold without power for a day or so. Were I setting off with my limited fuel/holding/water capacity for several days or a week using anchorages rather than marinas, I would have to decide whether to unplug and pull it out, or let it be. As you colorfully point out, after a day without power the ac reefer is a hunk of metal and foam useful only as storage.
I am curious, Maine, as to why an entire second ac feed from the shore source to panel is necessary, particularly if I could have run the reefer off the ac panel. My shore/IC 2000 is set up as you suggest (Battery + Terminal > Class T Fuse > ON/OFF Batt Switch > Inverter + DC Terminal) except I happened to have on hand and used an on/off circuit breaker where you suggest a Batt switch. BTW, if I did that more or less correctly it was, I'm sure, completely inadvertent.
The ac wiring from shore is probably 10/3 as is the shore power cord I suspect. But everything from the new bus > breaker > 0-1-2 switch > plug, and bus > ac panel breaker > 0-1-2 switch > plug, is 8/4 because I already had the wire.
As you point out, any effort to manually stop the 2000 from automatically switching to inverted ac power, will also disable the charger. I don't really contemplate using the reefer on inverted power, particularly on anything more than a 2 day sail. As others have pointed out, apparently they will stay cold without power for a day or so. Were I setting off with my limited fuel/holding/water capacity for several days or a week using anchorages rather than marinas, I would have to decide whether to unplug and pull it out, or let it be. As you colorfully point out, after a day without power the ac reefer is a hunk of metal and foam useful only as storage.
Course you could wire the AC panel so the electric water heater, Ac fredg, and battery charger do not operate off the inverter. All the outlets and appliances will operate off shore power but the inverter circuit is a "sub panel" that can't be connected to it. This requires a significantly more expensive source selector switch though.
shore power connects shore power to both outlets and high draw appliance circuits
inverter connects to only the outlets.
This is the way mine is set up. I was fortunate that the PO had a switch that just needed to be re-wired. he had three sources and the engine driven 120 volt AC alternator went south freeing up the third circuit in the switch..
shore power connects shore power to both outlets and high draw appliance circuits
inverter connects to only the outlets.
This is the way mine is set up. I was fortunate that the PO had a switch that just needed to be re-wired. he had three sources and the engine driven 120 volt AC alternator went south freeing up the third circuit in the switch..
Actually a source selector switch isn't required if it is wired as shown below. A circuit breaker on the main panel controls the AC input to the inverter and the AC output goes to the sub panel which has only those circuits that you want to power with the inverter.
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Yes no need to rewire the boat just turn the inverter switch off. It is quite possible to use the dorm refrigerator running through the inverter when underway with a little planning. First precool the unit to its lowest temperature setting a day or two before departing on a trip and then reset the thermostat to a higher temperature when departing. A full refrigerator operates more efficiently than a partially filled one. Make sure you fill with frozen an cooled products as they will help maintain temperature. Underway limit the times that you open the door as cooled air will escape. It best to keep water, drinks and snacks in a separate ice cooler. You can alternate running the refrigerator for one hour on and two hours off and run the engine for the hour the unit is running to maintain battery charge. A precooled dorm refrigerator will draw around 3.5 amp/hours as the compressor will run no more than 15 minutes in every hour. Now you can expect that a unit that has been allowed to loose its cooled temperature to consume as much as 13 amps per hour upon restart. You can plan overnight stops at marinas for a hot shower, a restaurant and to recharge batteries and again precool the refrigerator. These stops could also be used to restock the unit and get ice for the drinks. We used to do the planning and it worked as we found we could stay away from shorepower for up to 72 hours but then decided to add a Honda 2000 generator which would allow us to recharge the batteries every evening. This relieved us from having to be on top of refrigeration usage. We now have a built in 12V refrigerator with more capacity and although it is a little more efficient than the dorm/inverter combo we realize the same principles of planning and recharging batteries still govern.
You might also consider a DC cooler or DC fridge. Truckers use these every day and they have come way down in price.. Koolatron & others make DC dorm style fridges that use about 6A and costs about $225.00 +/-. If you want better efficiency then an Engle, Whynter, Edge Star or other similar unit would be a better choice but they get more expensive.. The Engles are the most efficient I have seen but they now have some copy-cats. For what you want to spend on all the doo-dads to make the dorm fridge work you could buy the Koolatron or similar. Just google search DC refrigerator or DC cooler....
I have a customer who circumnavigated on his sail boat, came home and got bored, so bought a small catamaran/trawler to do the Great Loop. I installed an Engle (IIRC it was Engle brand) and a solar array. His Engle runs 24/7/365 and never gets shut off. Here in Maine it sat on the mooring the entire first summer he was outfitting it for the trip and the Engle ran 24/7 only supported by short motor runs from the mooring to the dock and by solar... I never saw that thing using more than 3.2A and even then it only runs only for a few minutes..
The Engle is below the red bucket. He had a custom Sunbrella cover made for it. It survived the Great Loop and that was all he was after....
Certainly not a massive array by any means..
I have a customer who circumnavigated on his sail boat, came home and got bored, so bought a small catamaran/trawler to do the Great Loop. I installed an Engle (IIRC it was Engle brand) and a solar array. His Engle runs 24/7/365 and never gets shut off. Here in Maine it sat on the mooring the entire first summer he was outfitting it for the trip and the Engle ran 24/7 only supported by short motor runs from the mooring to the dock and by solar... I never saw that thing using more than 3.2A and even then it only runs only for a few minutes..
The Engle is below the red bucket. He had a custom Sunbrella cover made for it. It survived the Great Loop and that was all he was after....
Certainly not a massive array by any means..
wuif, mitiemp's post shows how the Freedom 20 should be wired: the AC shorepower goes to the i/c FIRST, then to the AC panel, since this is the only way the ATS inside it can work. Either the shorepower is the source of AC power or the the inverter is the source.
Precooling is always a good idea. The only time I leave my boat plugged in is the day before I go out to anchor out.
The DC version sounds like a much better idea. And is sure simpler.
Good luck.
Precooling is always a good idea. The only time I leave my boat plugged in is the day before I go out to anchor out.
The DC version sounds like a much better idea. And is sure simpler.
Good luck.
I don't really think the 12v solution is practical for what I want. They are generally quite small and very expensive. For serious blue water sailing, absolutely. But for marina/coastal use, the 110 seems to be a much better choice/value per cu ft. Dan and Hummer, what size/brand units are you using? Stu, you're right of course. I followed the Freedom 20 manual for wiring except for the on/off switch I added.
Not at boat but going tomorrow. Did not sweat the brand as much as I did the measurements. It fits like a glove, even has a wooden cutting board mounted above it.
Here is what it looked like originally and with the dorm fridge installed. Photo was really about the microwave instal but you can see the fridge. Will take some better pics tomorrow.
Here is what it looked like originally and with the dorm fridge installed. Photo was really about the microwave instal but you can see the fridge. Will take some better pics tomorrow.
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I too suggested removing the oven in favor of the fridge but the admiral was not quite ready to let go of it [certainly not because I've benefited from copious amounts of baked goodies; lots of what we cook aboard is made in the pressure cooker]. That's why I decided I would commandeer the aft port berth for the reefer and storage. Big hang up is that the location wants a right-to-left opening door which seems opposite of standard except the reversible ones.