48v cabin redo

[Maineman]

I’m new here- first post.
My current system has the following: Xantrex 24V 4000 watt inverter. Xantrex 40 amp charge controller. Trace DC disconnect/overcurrent module. 2 PV panels 123W each. Diesel backup generator 5500w. Battery bank: 8 6v Trojan L16’s 370 amp hrs.4 in series 2 strings in parallel.
The Cabin is in northern Maine and is visited summer and winter for 3 weeks each time. Winter temps. can get to -20. Solar exposure is
minimal 3 hr./day.
System has been in use for 15 years and now the battery bank is dead.
I’d like to completely redesign the system from solar panels to battery bank. 48v - LiFePo4 batteries new PV panels etc.
We run a 120v well pump from the lake, AC lights, propane water heater and fridge and other AC items. Load evaluation is 2400 watt hours/day.
I didn’t design the system l had it installed. I’m no electrician but I’m sure I could do it myself. Please any suggestions on how to get it all together with a plan and diagram would be greatly appreciated.

 

[John Frum]

I’m new here- first post.
My current system has the following: Xantrex 24V 4000 watt inverter. Xantrex 40 amp charge controller. Trace DC disconnect/overcurrent module. 2 PV panels 123W each. Diesel backup generator 5500w. Battery bank: 8 6v Trojan L16’s 370 amp hrs.4 in series 2 strings in parallel.
The Cabin is in northern Maine and is visited summer and winter for 3 weeks each time. Winter temps. can get to -20. Solar exposure is
minimal 3 hr./day.
System has been in use for 15 years and now the battery bank is dead.
I’d like to completely redesign the system from solar panels to battery bank. 48v - LiFePo4 batteries new PV panels etc.
We run a 120v well pump from the lake, AC lights, propane water heater and fridge and other AC items. Load evaluation is 2400 watt hours/day.
I didn’t design the system l had it installed. I’m no electrician but I’m sure I could do it myself. Please any suggestions on how to get it all together with a plan and diagram would be greatly appreciated.

If your you daily usage is only 2400 watt hours I wonder if you might be well advised to keep the Xantrex inverter.
If its one of the old ones designed by Trace you will have to spend serious dosh to get something similarly rugged.

Are you wanting to go to split phase?
If you were to upgrade to 48 volts with plans of going to split phase I would have a look at this.

Samlex EVO-4248SP 4200W, 48V Split Phase Pure Sine Inverter/Charger | DonRowe.com

The Samlex America EVO-4248SP, 4200 Watt, 48 VDC, 120/240 VAC Split Phase Pure Sine Wave Inverter/Charger with 60 Amp Charger is a rugged inverter/charger designed for back up and off-grid applications

www.donrowe.com

Do you have an pure dc loads?

 

[Maineman]

Thanks for your response. I’m not completely sure what split phase is or what it can do for me. I have no pure dc loads as everything was wired for AC outlets ect. I don’t have a problem with spending the cash to replace my old inverter as it is outdated. Also I miscalculated the daily watt hrs. It’s more like 2800,

 

[John Frum]

Thanks for your response. I’m not completely sure what split phase is or what it can do for me. I have no pure dc loads as everything was wired for AC outlets ect. I don’t have a problem with spending the cash to replace my old inverter as it is outdated. Also I miscalculated the daily watt hrs. It’s more like 2800,

Split-phase electric power - Wikipedia

en.wikipedia.org

Most 48 volt inverters are split phase.
Most AC load centers are designed for split phase.
Split phase load centers have interleaved "houndstooth" busbars.

 

[John Frum]

If you are willing to post a picture of your load center it will help us to advise you.

 

[John Frum]

This one is 120VAC only.

Samlex EVO-4024 4000W, 24V Pure Sine Inverter/Charger | DonRowe.com

The Samlex America EVO-4024, 4000 Watt, 24 Volt Pure Sine Wave Inverter/Charger with 110 Amp Charger is a rugged inverter/charger designed for mobile and off-grid applications

www.donrowe.com

 

[MichaelK]

Battery bank: 8 6v Trojan L16’s 370 amp hrs.4 in series 2 strings in parallel.
The Cabin is in northern Maine and is visited summer and winter for 3 weeks each time. Winter temps. can get to -20. Solar exposure is
minimal 3 hr./day.
System has been in use for 15 years and now the battery bank is dead.

Of course the battery is dead. 246W is tiny for a battery that size. Grossly inadequate for proper charging. Trojan specifies 1/8th of C (0.125C) for charging as being best for their L-16 batteries. With two parallel strings of 370Ah that's 370Ah X 2 strings X 0.125C = 92.5A.

That amounts to (123W X 2 panels)/26V charging = 9.46A. Assuming you only get 85% of nameplate under real-world conditions, that's only 8.0A. Not even 1/10th of what those batteries should have been getting.

Now if you want to run a 120V well-pump, the power needed will be proportional to the horsepower rating, but let's take a guess and say 1500W. I usually recommend the 2X rule for solar, which is use 2X the number of panels as your single largest load. If that load is a 1500W well-pump, that means have 3000W of panels.

Getting back to the numbers in the first paragraph, to get an honest 92.5A of charging, you need (92.5A X 26V charging)/85% de-rating = 2830W of solar. Notice how close that comes to the 3000W recommendation for the pump. This would be an example of proper scaling of your system components.

Now, assuming you only get about 2.0 sunhours in Maine in winter, 3000W of solar should easily make your 2400W minimum every single day, with enough extra capacity to fully charge the batteries after a few days of cloudy weather.

BTW, I also recommend the 2X rule for sizing your inverter. If your biggest load is 1500W, I would recommend getting at least a 3000W sine-wave inverter.

 

[John Frum]

Is your generator 120VAC or 120/240VAC?

 

[Maineman]

Is your generator 120VAC or 120/240VAC?

OK I added a few pics to give you a better idea of what I have and yes, the generator is 120/240. You asked for a pic of the load center. I assumed you mean the load evaluation chart?

 

[Maineman]

OK I added a few pics to give you a better idea of what I have and yes, the generator is 120/240. You asked for a pic of the load center. I assumed you mean the load evaluation chart?

Sorry for the size of the pics. These are better.

 

[MichaelK]

Thanks for your response. I’m not completely sure what split phase is or what it can do for me. I have no pure dc loads as everything was wired for AC outlets ect. I don’t have a problem with spending the cash to replace my old inverter as it is outdated. Also I miscalculated the daily watt hrs. It’s more like 2800,

Split-phase operation is the American solution for supplying power for big ticket items like electric stoves and electric hot water heaters. The simple explanation is that electricity coming from the utility is coming into your local spot at 240AC. There's a transformer somewhere nearby outside your house that has a center tap which "splits" the AC into two parallel streams of 120V power, which a 180 degrees out of phase with each other. That's the rather simple layman's explaination.

So, three wires plus ground are coming into your house, L1, L2, and Neutral, N. L1 to N is 120V. L2 to N is 120V. But, L1 to L2 is 240V. So, every standard electrical load center (the breaker panel) has the breakers divided up to L1, and L2 circuits. In the breaker panel, the breaker terminals are staggered so that an L2 terminal is always right next to an L1 terminal. This facilitates wiring both single and double pole breakers in the same panel. All the single-pole 120V hot leads go out to your wall sockets. The bigger double-pole sockets run out to your big-ticket 240V items like the stove, water heater, and the central air-conditioner. The newer cabin/home scaled inverters are designed to be seamlessly be wired into a standard split-phase panel.

Getting back to your own system, you may chose to have a pure 120V system, or a split-phase system, depending on what inverter(s) you want to get. The well-pump sounds like it will be your single biggest load, so you may chose to design the system around that. That's what I did for my own design. So, it's going to be critical to find out the specs of your pump if you want your system to run the pump. Here's a pump chart that illustrates how much power is consumed by which sized pump.

Going back to the example of the 1/2 hp pump I mentioned above, you can look at this chart to see it's requirements. It appears that the 1/2hp needs 12A to run but 42.5A to start. That means ~1400W running, but 5100W starting. That's a 3.5X starting surge which is very typical for a well-pump. So, you need an inverter that can handle a starting surge of >5000W for at least 500 milliseconds. Note that most high-frequency inverters can only surge to 200% for ~ 16 milliseconds, so the CANNOT start a well-pump.

It looks like Outback is one choice, with either the VFR series, or the smaller Radian.



Another choice is Schneiders Conext series. Note that max surge is listed for 240V. You might want to contact Schneider and talk to an applications engineer about whether or not a single-leg can support a starting surge of 5100W.

 

[John Frum]

You asked for a pic of the load center. I assumed you mean the load evaluation chart?

I mean the ac distribution panel.
Here is an example.

CQO160M200PC - Square D 200 Amp Main Breaker Only Plug-on Neutral Loadcentre with 60 Spaces, 80 Circuits Maximum

Square D 200 Amp Main Breaker Loadcentre This service entrance panel is connected to the electrical meter and distributes electricity throughout the home. Each is equipped with a factory installed main circuit breaker. Square D plug-on neutral loadcentres are designed to accept the plug-on...

www.canadabreakers.ca

 

[John Frum]

I can't make out any detail in the pictures.
From what I can see it looks like pretty decent kit.

 

[John Frum]

Can you please take a close up shot of each of the white boxes on the wall.

 

[DPC]

Just my own opinion....
I would put a sheet of 1/2 sheet rock between the electrical bits and the wood.

I would buy the smallest tub from Cutler Hammer.
If you find you want to add later you can use the slim double breakers

Search ebay and such for used parts, but buy new breakers if you want to save money
here's a nice one breakers look good

Eaton CUTLER HAMMER BR816L125GP 125 Amp LOAD CENTER 60 Amp Main 5 additional 786676002110 | eBay

Eaton CUTLER HAMMER BR816L125GP 125 Amp LOAD CENTER 60 Amp Main 5 additional.

www.ebay.com

It crazy what people want for stuff but here is the kind of thing your looking for to switch between your inverter and generator

Eaton DT461URK 30 Amp Heavy Duty Double Throw Safety Switch 600V 4 Pole | eBay

Find many great new & used options and get the best deals for Eaton DT461URK 30 Amp Heavy Duty Double Throw Safety Switch 600V 4 Pole at the best online prices at eBay! Free shipping for many products!

www.ebay.com

That well pump....
Are you drawing water from a lake?
How far you need to push it?
Maybe use an RV pump and run it off DC?


When you out driving on garbage day always look at what people throw away when they renovate.
Sometimes you find all this stuff at the side of the road

 

[Johneb]

X2 for Samlex.