Inverter for one outlet...calling on the experts.

ocgrant

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OK calling all inverter experts. I have a 48 Sundancer that has a fridge on the aft deck that I want to replace with a Uline Icemaker. Problem is I dont want to run gene we I leave the dock for just an icemaker that only runs on AC voltage. So my thoughts were the following

1. I have a 24 volt battery bank for the thruster that never gets used that has its own charger on it.

2. Replace the thruster charger with a 24v inverter charger with auto switching and run the AC wire to an isolated outlet for the icemaker.

This way when I am on shore power the charger is charging the batteries and auto switching that outlet over to AC and when I take away shore power it will autoswitch over to inversion and convert the 24v DC to AC to power my ice maker.

Will this work?
 
That would work generally speaking, but the devil is always in the details. Space and cooling available for the inverter, distances between batteries and inverter, and how you wire it to the panel.

Done right it would be a really nice addition! I also run my coffee pot, microwave, vacuum and outlets and it was a pretty easy project once the engineering was completed.

Just one note, buy a true sine inverter. Modified sine wave inverters are tough on compressors. True sine wave inverter are coming down in price.
 
That will certainly work if done properly. just make sure the battery is properly sized.
 
That is exactly how ours is set up and works wonderfully. Ours powers outlets to run misc appliances, TV, vacuums, chargers, fan, etc. Only a 1250 watt, so no air cond or heavy loads. Definitely a nice quiet addition. We power it from the fwd accessory switch on the helm. All of the components are in the compartment to the right of the helm.
 
"Debbie downer" here - the killer is the compressor inrush starting loads which can be two to three times the operating current on the ice maker. So, let's say your ice maker has an operating load of 600 watts which is 5 amps at 120VAC and 25 amps at 24 VDC. Starting inrush current is 15 amps at 120VAC which is a very high 1800 watts and 75 amps at 24 VDC. So an inverter to include inefficiencies needs to be rated at 2500 watt minimum. I would use a Victron Multiplus 24/3000/70 unit.
Now for battery sizing - you probably have two 12V 90AH batteries tied in series which gives 90AH at 24VDC. You can only use 50% of the batteries energy for lead acid batteries so that gives 45AH of capability. This means for rated operating loads on the icemaker you would have 3.6 hours operating time less starting inrush current and inverting inefficiencies so more like a maximum of 3 hours the icemaker could operate on a fully charged battery bank.
The raw facts......
 
"Debbie downer" here - the killer is the compressor inrush starting loads which can be two to three times the operating current on the ice maker. So, let's say your ice maker has an operating load of 600 watts which is 5 amps at 120VAC and 25 amps at 24 VDC. Starting inrush current is 15 amps at 120VAC which is a very high 1800 watts and 75 amps at 24 VDC. So an inverter to include inefficiencies needs to be rated at 2500 watt minimum. I would use a Victron Multiplus 24/3000/70 unit.
Now for battery sizing - you probably have two 12V 90AH batteries tied in series which gives 90AH at 24VDC. You can only use 50% of the batteries energy for lead acid batteries so that gives 45AH of capability. This means for rated operating loads on the icemaker you would have 3.6 hours operating time less starting inrush current and inverting inefficiencies so more like a maximum of 3 hours the icemaker could operate on a fully charged battery bank.
The raw facts......

Those are spot on calculations. I would suggest a minimum of 3 (300 ah)quality group 31 agm batteries and a easystart to help reduce startup draw. You should get a full afternoon out of that and can run the Genny to recharge. Not a inexpensive proposition to do correctly. Proper equipment would be the key.
 
And, the recharge to battery float after depletion to 50% (150AH used) for lead acid using the generator will be between 3 to 4 hours of run time. It's the absorption charging phase that takes so long.
 
Another dissenting observation/opinion - not running your generator is the worst thing you can do for your generator.

Skip the inverter and give your generator the hours she needs to stay healthy. My crappy old 1997 ice maker will still have ice in the box after an overnight of not having AC power. Start the generator for breakfast/coffee and by the time you need your first drink you'll have a fresh top coat of new ice over the 2/3rds that didn't melt the night before.

My two cents only...
 
Another dissenting observation/opinion - not running your generator is the worst thing you can do for your generator.

Skip the inverter and give your generator the hours she needs to stay healthy. My crappy old 1997 ice maker will still have ice in the box after an overnight of not having AC power. Start the generator for breakfast/coffee and by the time you need your first drink you'll have a fresh top coat of new ice over the 2/3rds that didn't melt the night before.

My two cents only...
Trust me in South Florida my geney gets plenty of run time to keep 4 AC units pumping cold air when wifey is hot!!! LOL
 
"Debbie downer" here - the killer is the compressor inrush starting loads which can be two to three times the operating current on the ice maker. So, let's say your ice maker has an operating load of 600 watts which is 5 amps at 120VAC and 25 amps at 24 VDC. Starting inrush current is 15 amps at 120VAC which is a very high 1800 watts and 75 amps at 24 VDC. So an inverter to include inefficiencies needs to be rated at 2500 watt minimum. I would use a Victron Multiplus 24/3000/70 unit.
Now for battery sizing - you probably have two 12V 90AH batteries tied in series which gives 90AH at 24VDC. You can only use 50% of the batteries energy for lead acid batteries so that gives 45AH of capability. This means for rated operating loads on the icemaker you would have 3.6 hours operating time less starting inrush current and inverting inefficiencies so more like a maximum of 3 hours the icemaker could operate on a fully charged battery bank.
The raw facts......
Debbie...LOL You are spot on and that should work fine as the geney will have some run time during the day for sure. I might have space to double the capacity of the battery bank but not sure yet. This project is in the future but wanted to get a second opinion before I move forward with aquiring the equipment needed to proceed. Thanks for the direction.
 
Debbie...LOL You are spot on and that should work fine as the geney will have some run time during the day for sure. I might have space to double the capacity of the battery bank but not sure yet. This project is in the future but wanted to get a second opinion before I move forward with aquiring the equipment needed to proceed. Thanks for the direction.
One thing we didn't bring up is the Ice Maker duty cycle which is quite dependent where you live and how much ice you demand - if it runs 15 minutes per hour that is really 12 hours on the batteries (300AH) which is still "3 hours operating time".
 
Oh those damn details...
 
OK calling all inverter experts. I have a 48 Sundancer that has a fridge on the aft deck that I want to replace with a Uline Icemaker. Problem is I dont want to run gene we I leave the dock for just an icemaker that only runs on AC voltage. So my thoughts were the following

1. I have a 24 volt battery bank for the thruster that never gets used that has its own charger on it.

2. Replace the thruster charger with a 24v inverter charger with auto switching and run the AC wire to an isolated outlet for the icemaker.

This way when I am on shore power the charger is charging the batteries and auto switching that outlet over to AC and when I take away shore power it will autoswitch over to inversion and convert the 24v DC to AC to power my ice maker.

Will this work?
I have an inverter powered off my bow thruster batteries doing exactly what you describe. It still works like a champ.

There was a previous discussion on this several years ago. I couldn't find it on the forum search but did find it via google.
http://www.clubsearay.com/index.php?threads/searay-sedan-2004-inverter-installation.70080/

The entire thread is useful. Post #16 is where mine is described.
 
I bought a xantrex sw 2024 inverter charger ,my intentions was to use the bow thruster and house 24 volt battery’s to run the system .i decovered that the charger will not work if you happen to run the battery’s down to 20 volts .What this means is if you are on the hook and forget to turn off all the lights you better have sea tow to come and give you a jump ,yup the generators running but the charger will or can not charge the battery’s .After calls to xantrex I was informed that the charger inverter will only maintain battery levels above 20 volts if you find you battery down you are stuck ,but it gets better,I was talked into the generator auto start ,after 8 calls to xantrex to get the correct protocol to get the gen to run automatically we got it would start but you had to go down in the engine room to shut off the generator,exc ,exc .now I am in the process of re installing my old 20 year old quality marine was Mccaron charger ordered a new up date board and just use the inverter on this piece of junk xantrex .
At this point I have a generator auto start that does not start or it will not shut off and a charger that doesn’t charge, and I am not kidding.
 
I bought a xantrex sw 2024 inverter charger ,my intentions was to use the bow thruster and house 24 volt battery’s to run the system .i decovered that the charger will not work if you happen to run the battery’s down to 20 volts .What this means is if you are on the hook and forget to turn off all the lights you better have sea tow to come and give you a jump ,yup the generators running but the charger will or can not charge the battery’s .After calls to xantrex I was informed that the charger inverter will only maintain battery levels above 20 volts if you find you battery down you are stuck ,but it gets better,I was talked into the generator auto start ,after 8 calls to xantrex to get the correct protocol to get the gen to run automatically we got it would start but you had to go down in the engine room to shut off the generator,exc ,exc .now I am in the process of re installing my old 20 year old quality marine was Mccaron charger ordered a new up date board and just use the inverter on this piece of junk xantrex .
At this point I have a generator auto start that does not start or it will not shut off and a charger that doesn’t charge, and I am not kidding.

We have a 3000 watt pure sine inverter charger that handles two 4D 210 AH house batteries. We also have a remote controller that handles the inverter charger functions, and provides a low voltage shut off in inverter mode to prevent the batteries from discharging too much.

As I understand it is a characteristic of inverter/chargers that they will not work in either function when the batteries are discharged too low. So if the batteries are discharged too far you will need an external charger to get the batteries back above the minimum level before the inverter/charger will function.
 
I bought a xantrex sw 2024 inverter charger ,my intentions was to use the bow thruster and house 24 volt battery’s to run the system .i decovered that the charger will not work if you happen to run the battery’s down to 20 volts .What this means is if you are on the hook and forget to turn off all the lights you better have sea tow to come and give you a jump ,yup the generators running but the charger will or can not charge the battery’s .After calls to xantrex I was informed that the charger inverter will only maintain battery levels above 20 volts if you find you battery down you are stuck ,but it gets better,I was talked into the generator auto start ,after 8 calls to xantrex to get the correct protocol to get the gen to run automatically we got it would start but you had to go down in the engine room to shut off the generator,exc ,exc .now I am in the process of re installing my old 20 year old quality marine was Mccaron charger ordered a new up date board and just use the inverter on this piece of junk xantrex .
At this point I have a generator auto start that does not start or it will not shut off and a charger that doesn’t charge, and I am not kidding.

Just to start this off, I'm not an expert. I have had the SW 3024 installed for several (about 5) years which is the 3000 watt version of your unit. I also have a few friends with the SW 2012 so fairly familiar with the operation.

I don't think you should allow your inverter to draw your batteries down to 20 volts. My understanding is that is far below the 50% point for reasonable battery life as it will do permanent damage. In your control panel you can set the Low battery cutout value to whatever you want. I think I have mine (agm's) are set at 21.5 or 22 volts. What is yours set at?

A lot of the smart chargers now available have low voltage limits. A great reason for me to hang on to that old Craftsman charger from the 80's. Anyway, I think I recently ran across a Force Charge mode on the Xantex. I haven't used it but perhaps that will work if it ever happens again (perhaps drawn down by something other than the inverter, like the bow thruster). Worst case, carry jumper cables. Crank your engines (assumed 24V), then use the alternator to add a few more volts to the inverter batteries to get over the hump.
 
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No expert but this is what we have 4 x 6-volt G.C. batteries (Costco) Xantrex 3000w. 120 from shore or gen is switched through the inverter, so our 120v panel is hot all the time with shore, gen, or inverter (I like this as I do not have reset the clocks on the coffee maker or microwave).
 
Just to start this off, I'm not an expert. I have had the SW 3024 installed for several (about 5) years which is the 3000 watt version of your unit. I also have a few friends with the SW 2012 so fairly familiar with the operation.

I don't think you should allow your inverter to draw your batteries down to 20 volts. My understanding is that is far below the 50% point for reasonable battery life as it will do permanent damage. In your control panel you can set the Low battery cutout value to whatever you want. I think I have mine (agm's) are set at 21.5 or 22 volts. What is yours set at?

A lot of the smart chargers now available have low voltage limits. A great reason for me to hang on to that old Craftsman charger from the 80's. Anyway, I think I recently ran across a Force Charge mode on the Xantex. I haven't used it but perhaps that will work if it ever happens again (perhaps drawn down by something other than the inverter, like the bow thruster). Worst case, carry jumper cables. Crank your engines (assumed 24V), then use the alternator to add a few more volts to the inverter batteries to get over the hump.
No expert but this is what we have 4 x 6-volt G.C. batteries (Costco) Xantrex 3000w. 120 from shore or gen is switched through the inverter, so our 120v panel is hot all the time with shore, gen, or inverter (I like this as I do not have reset the clocks on the coffee maker or microwave).
Hi Brett
I do understand the whole posses of drawing down the battery's this I agree with you .The issue is that if you left the lights on or whatever on, and went to bed the next morning the you will have no way to start the boat .I know it has a minim voltage shut down ,but if the draw is behind the inverter you have no way to charge the battery's you can run the gen for days and you still will have a dead battery .It is represented to be a battery charger ,it is not it is at best a trickle charger.My frustration is that there customer survive is horrible i Emailed a return request and they never answered then when I called they gave me the survive centers number and when I wanted to have this checked out because i still am not sure the unit is working correctly none of there northeast service centers did warranty repairs ,for 225.00 they would bench test it but thats it . The other problems I had was the auto gen start ,we tried 6 different wiring protocols and it still does not work correctly,I don't have to tell you how frustrating it is to keep rewiring the gen circuit to try to get it to work .
 
Hi Brett
I do understand the whole posses of drawing down the battery's this I agree with you .The issue is that if you left the lights on or whatever on, and went to bed the next morning the you will have no way to start the boat .I know it has a minim voltage shut down ,but if the draw is behind the inverter you have no way to charge the battery's you can run the gen for days and you still will have a dead battery .It is represented to be a battery charger ,it is not it is at best a trickle charger.My frustration is that there customer survive is horrible i Emailed a return request and they never answered then when I called they gave me the survive centers number and when I wanted to have this checked out because i still am not sure the unit is working correctly none of there northeast service centers did warranty repairs ,for 225.00 they would bench test it but thats it . The other problems I had was the auto gen start ,we tried 6 different wiring protocols and it still does not work correctly,I don't have to tell you how frustrating it is to keep rewiring the gen circuit to try to get it to work .

I guess I'm missing something. Leaving 120V lights on shouldn't affect inverter/bowthruster batteries as once it gets to the minimum discharge set point it turns off. From a point >20V the generator & charging portion of the Xantrex should be able to recharge. Any other lights (24V or 12V) would be probably be tied in to the engine /house batteries.

I have a separate group 31 (12V) on my Gen so it will pretty much always start which can provide power to the chargers or inverter/charger.

I have 6 8D Batteries. All three pairs are AGM's. I'm just now converting my engine/house batteries to AGM (NorthStar) so that they will hopefully last longer than the original 7 year old West Marine Flooded batteries, since I seem to be spending more time on the hook recently and due to the nice weather rarely need to run the gen.

One pair (24V) for each engine that also operates 1/2 of the "house". The third pair (24V) is the inverter/thruster (set to stop discharge at 21.5V) so at this point it will always recharge since its over the 20V limit you described. No matter how forgetful (beer, margaritas, vodka etc) I get there is always at least one alternate source available (typically 2 as in both engines/house) thus providing an option for recharge in some form or fashion, especially after changing the majority of bulbs to LED.

Regarding the poor support comment, sorry to hear. I can't help with auto gen start as I didn't choose that feature. I suggest you find a local high end RV shop that know the ins/outs of the Xantrex and the Auto Gen Stop. Then bribe him to work on that specific function of your inverter.
 
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