2120 - "Cat's Cradle"- Off Season Projects

[shawnee83]

Last post for this thread as I'm finished doing all that I'm going to do until maybe late fall. Anyway, got to the clean up part. I used the Barkeepers friend and the Acrylic ZEP wax. It really turned out nice and it also did I nice job sealing and shining up the non skid all over the boat. I took a chance on this stuff so now it will be interesting to see how it holds up to the rigors of salt water sand, fish blood etc. I'll let you know.

 

[Megabyte]

Dude... your making me dizzy. :shock:

Congratulations!

 

[shawnee83]

Thanks Kevin. Glad it's done.

 

[shawnee83]

Well it looks like I'm going to get one more item checked off my list a little sooner than I expected to. The last component of the electrical system project has been ordered and I should have it Monday. That is the Xantrex Prosine 1800 Pure Sine Wave Inverter. I've already pre wired everything for the install so it should be reasonably easy to finish up. I'm pretty excited to be getting to this sooner than expected and also excited to see it work and the whole system come together. According to my calculations I should be able to run my AC/Heat about 4 hrs with the engine running. I really wish that I had one of the newer 4.2L Yamaha Offshore series engines as I think the larger Alt output (70 Amp)of the 4.2's vs. my 3.3L F225 (44 Amp) would net me about 10 hrs of AC run time with my current set up. The approximate break even DC Amps needed to run the AC is about 52 ish. I hope to get to Beaufort next weekend and do the install. I'll post pics and results.

 

[rwp48]

Wow Shawnee! How big is your battery bank? I can't imagine being able to run a marine air unit for that long without a huge bank of battery power!

 

[shawnee83]

Wow Shawnee! How big is your battery bank? I can't imagine being able to run a marine air unit for that long without a huge bank of battery power!

Hi Randy, I've added this Vmaxtanks 200AH AGM to my bilge (for house side) and I have a Optima D34M AGM in the starboard jump seat for my start battery. I have a 4/0 AWG wire run from the Vmax house to where the inverter is going to mount in the port jump seat compartment. Previous pics in this thread show the set up. According to my calculations and after speaking with the techs at Xantrex, it should work? Trust me, I will be crossing both fingers when I try to fire the AC compressor for the first time. Should be about 2700 watts to fire and 750 ish to run after.

 

[rwp48]

Remember that you should never discharge a battery below 50%. That means you have 100 amps usable. If I'm doing the math correctly, at 12 volts that's 1200 watts. The start loads on the compressor are momentary so you may be able to overcome that but I think you are going to start running out of juice in hour #2 unless the alternator can put back some serious amps.
But whatever you do, don't trust my math! Recheck my work!

 

[shawnee83]

I agree with your math Randy. I've calculated this thing so many ways that I've confused myself. Anyway, with the engine running I should get in the neighborhood of 2 hours out of it and maybe 2.5 if I'm lucky. It will depend on cycling etc...? With new 70 Amp 4.2L if I had one, it would be more like 6? The running watts after the compressor is started is about 667 watts. According to the Webasto FCF specs, it will spike to about 2800 watts on start up. 23.5 Amps at 115V AC is start up and 5.8 Amps at 115V AC is running. If compressor cycles off it is obviously less than 5.8 but I don't know how much? I've calculated based on it not cycling as I figured it would be better to set the temp all the way down to prevent cycling? I only plan to use it when I'm coming off the docks and I need to run out of the no wake areas or maybe all the way out to the Cape which typically is about 30 minutes each way. Another 2120 owner set one up and I got the idea from him. Honestly, I don't think I would do it again after going through all the pain in the butt work and the money I have spent for this inverter part. It will be nice to have but probably not worth all the effort. I've learned a lot from this project though so all good.

 

[rwp48]

Hi Shawnee!
Check with the manufacturer about using a soft-start capacitor. Might mitigate the heavy "shock load" on startup. Also, if you are dockside, run the A/C on shore power to pre-cool the boat and start the A/C when there is plenty of power. The transfer switch should make the changeover seamless. The power on our trawler's inverter doesn't even blink when it switches over from shore power.

 

[shawnee83]

Hi Shawnee!
Check with the manufacturer about using a soft-start capacitor. Might mitigate the heavy "shock load" on startup. Also, if you are dockside, run the A/C on shore power to pre-cool the boat and start the A/C when there is plenty of power. The transfer switch should make the changeover seamless. The power on our trawler's inverter doesn't even blink when it switches over from shore power.

Good points Randy. I've read up on the soft start options and I think it would work however the one I saw was almost $500 so not very appealing at this point. As I've mentioned in my earlier post about making mistakes during this process, the transfer switch situation was one of those mistakes. When I originally set my AC side up, I installed a Blue Seas 30A duel source main. At that time I had not figured out what inverter I was going to use and combined with my lack of understanding of the inverters transfer switch possibilities, I failed to design for that. Ive already wired for the inverter using just one line to the 30A main as inverter In and at this point it is such a pain in the butt running wires on the small 2120 that I just don't have it in me to redo it. The only thing that makes me feel slightly ok about it is that I would only be able to take advantage of the transfer one way when leaving the dock but not leaving from the Cape or wherever not on shore power. I've enjoyed the challenge of this project being self taught on the electric side along with a lot of help from guys here on CP, but I have made a few mistakes. Fortunately, none that are safety related. I feel pretty good that I have done a decent job on that part? Maybe I'll revisit the soft start option as the only one that I checked out was the Dometec Smartstart 11.

 

[Brent]

on the flip side

A Honda 1000 or 2000 genset would allow longer run time and there is an external run gas cap to external tank, and makes AC juice.

m2cw

 

[shawnee83]

on the flip side

A Honda 1000 or 2000 genset would allow longer run time and there is an external run gas cap to external tank, and makes AC juice.

m2cw

Absolutely Brent. My 30A inlet is under the Gunwale starboard side where the rod holders poke through to the cabin so running the cord to wherever or say the top of the port jump seat where I could place the Honda 2000 would certainly work. I've definitely considered this option if I was staying out on the hook for the night etc... (stage 3, and another $1K+, lol) The inverter option was more for ease while underway. Usually when I'm running like most, there is a lot of spray flying and I wouldn't want the gen getting salt water spray. For overnighting though I agree. Would also need a Carbon detector also for that but no big deal there.

 

[shawnee83]

Well I made a special trip to Beaufort yesterday by myself to do the inverter install and to check the last box on this crazy electrical system project. I'm happy to report that the Xantrex Prosine 1800 fired the compressor with no issues and it seems to run the AC without stressing it at all. As usual with just about everything on this project, I had an issue. I originally planned to mount the inverter in the jump seat sideways on the verticle to the transum part of the jump seat compartment. I knew if it fit it would be by less than 1/4", and of course, it didn't fit that way. I could actually get it in there but then I couldn't get to the screws on the top to mount it. I somewhat expected that so I'm going to plan B and it will be mounted in the position you see in the pic flat & mounted to the deck. Unfortunately, I forgot to bring my saw and left over starboard as I want to block mount it up off the deck with the starboard to keep any potential water etc from the inverter. I didn't want to mount it this way as it eats up my limited storage space. Although, I'm only planning to use this space for some boat soap and a few things like that. The pic of the remote shows the power draw while it was running the AC. FYI - I temporarily hooked up the remote behind the dash for now to run the test, it will mount on the front of the dash next to the other controls and the 30A switch. I didn't want to cut another hole in the dash until I knew it would work. I'll finish up the instal on my next trip in a couple of weeks. For you guys out there that have the newer 4.2L Yamaha's, this set up would be much more viable as you have a larger 70A alternator on yours and I think you would get north of 6 hrs of run time with the enging running. If for nothing else than winter time fishing, it would keep you warm vs running gas heaters? Hope everyone is having a good season thus far. Enjoy!

 

[shawnee83]

I realized that I never posted any finished pics of the inverter mounting in the port jump seat so I’ve added a few. I didnt get around to mounting the inverter remote control at the dash though so it’s still temporiarly connected behind it. I’ll mount it in the spring. I made some starboard block mount brackets for the inverter which are hard to see but they keep it off the deck and they have side pieces to keep things stored in the compartment off the inverter.

 

[Megabyte]

Nice work. 8)

 

[shawnee83]

Thanks Kevin. Last month I finally had a chance to give the set up a good test and i ran the AC on it about 2.25 hrs without issue. I think to keep to the no more than 50% discharge rule on the battery I need to shut it down at about 2.5 hr according to calculations. I wish there was a way to increase my charging output but I’ve not found anyway to do that on an outboard without changing the motor.

 

[fannin]

Looking into adding AC to my 2530 in the future and was looking at different options. Im thinking inverter and battery may be the best bet for me too. I have twins so thats a combined 100amp output. BEP setup along with a 4d or 8d house battery just for the AC may give me 5 or 6 hours of run time?

Idea #2 Dewalt 1800 Watt Power Station http://www.dewalt.com/products/acce...station-and-parallel-battery-charger/dcb1800b

I haven't been able to figure out the math on it 100%, maybe someone else can. You can have 4 60volt 9aH batteries in it for maximum use. I've watched a few youtube videos where people are running refrigerators off of this for anywhere from 4 to 14 hours. Plus the ability to bring additional batteries along to switch out. Then plug it back in to shore power and charge everything back up.

 

[shawnee83]

Looking into adding AC to my 2530 in the future and was looking at different options. Im thinking inverter and battery may be the best bet for me too. I have twins so thats a combined 100amp output. BEP setup along with a 4d or 8d house battery just for the AC may give me 5 or 6 hours of run time?

Idea #2 Dewalt 1800 Watt Power Station http://www.dewalt.com/products/acce...station-and-parallel-battery-charger/dcb1800b

I haven't been able to figure out the math on it 100%, maybe someone else can. You can have 4 60volt 9aH batteries in it for maximum use. I've watched a few youtube videos where people are running refrigerators off of this for anywhere from 4 to 14 hours. Plus the ability to bring additional batteries along to switch out. Then plug it back in to shore power and charge everything back up.

First of all, just to confirm that this is a concept that works with the engines running only. You can run off of the 4D battery with no motor running but not for a long period of time(maybe an hour?). If you want to overnight with AC you will need to go generator or be willing to run both engines at about 2K RPM to get through the night.
Secondly, I didn’t study the Dewalt spec to closely but I think it said 22lb shipping weight? Due to that and quick look specs tells me that the high power it says it can provide will be very short lived and not work for long duration draw. I would scratch that concept.
So, if you are looking for AC while underway without a generator the invertior and a good 4D AGM like I used will definitely work for you as you have the advantage of twins. My unit needs about 53 Amps DC break even. Remember, if your alt output is 45 for example, about 25 to 30 is available for charging/inverter use. With twins, that should be better depending on set up etc... but you should be in good shape as long as you don’t put to big a unit in.
Lastly, the battery charger and being able to connect to shore power after using the system is key to making it all work.
Inverter can’t be exposed to fuel tank, DC cables to inverter can’t be very long runs which is why I mounted mine in the jump seat. Lots more....hopefully a start for you. Mine works great but just wanted to be clear on the niche that it works for. Happy to assist if you have additional questions. Good luck