Should I power with 120v or 240v What are the benefits and pros and cons of running 120v vs. 240v under solar power?

sabo

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I have some lights that run either 120V or 240V I currently run them off the grid using 240V because the amp consumption is 1/2 compared to powering them off 120V. I will be installing an all in one inverter possibly the SPLIT PHASE LVX SERIES – LVX6048

https://www.mppsolar.com/v3/lvx6048/

powering off the grid running them on 240 V makes sense because I have some amperage limitations on the subpanel from which they are wired.

What are the benefits and pros and cons of running 120v vs. 240v under solar power?
 

snoobler

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240V has less losses due to wiring resistance. 2X voltage, 1/2 amps = 1/4 resistance.

Note that aside from the losses, they use the same amount of POWER, i.e., a given energy source will power them for about the same amount of time as they will use the same Watts at either voltage.
 

sabo

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That is the source of my confusion and the reason I am seeking more info. They use the same watts. I am assuming an inverter that powers 240V devices is for devices that only run on 240V. I am guessing in my case I dont really need 240V. What are the benefits of less resistance?
 

boondox

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The place where running 240VAC pays off the most is on heavy loads. For example, my water pressure pump is about 100 feet from my power center. So I ran 240 out there and wired the pump for 240. I could use smaller wire that way. Same thing for my welder, although it isn't all that far it is a pig for power. If the distance isn't far and the load is small the advantage is less. Since for 120 you only need 2 conductors + ground and for 240 you need 3 conductors + ground you may save a little sticking with 120. However, in general there really is no penalty for using 240.
 

MPRanger

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Of course the largest household consumer of 220v power is environmental control aka AC. Followed by clothes dryers, water heaters, well pumps and kitchen stove/oven.
 

MPRanger

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So; hang your clothes on a line to try, replace water heaters with on demand propane or NG, collect your drinking water in a cistern not a deep wel and cook with gas and you don’t need 220V if you live in the temperature of your grand parents. (Sweat)
 

Jodi

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Question I brought a European boat running 240V 30A. The blue wire is 120V.. the brown wire is 120v and green is ground. There is no neutral and I have reverse polarity plugged in to US power.
I have a victron 240v inverter
I am trying to fix the reverse polarity
I will also be installing solar and lithium battles this winter.

Is it better to go with an All in one like a growatt system or set uup individually components with automatic switching unit so I can have120V/240V.
Currently I took the blue wire and grn wire created a 120v outlet.
I believe the 240v set up is considered 2 phase, and the 120v a 1 phase.
I have 2 120v/240v Air Conditioners, I will be getting an AC/DC refrigerator.
I am looking at 1000ah lithium batteries and 1200W solar if I can get 4 ridge panels setup on an arch. I want to go with a 24VDC
Any advice greatly appreciated
Jodi
 
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Rednecktek

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Currently I took the blue wire and grn wire created a 120v outlet.

Ummm... that's not how it's supposed to work. What you're doing is dead grounding your system to the hull and dumping current into the hull. This is going to chew any metal you have to rust in no time flat and potentially damage your electrical system & generator if not zap you every time you grab a railing! We just had a ship down for a month because they didn't fix the grounds and it destroyed all the main engine bearings in a 4 story tall engine!

The reason there is no Neutral is because your system is designed to take 120v from L1 and 120v from L2 and provide the 240v that your boat is built to use. If you need 120v for N.American stuff, you need to get transformers involved that will create that Neutral line and/or step it to 60v on each leg to provide 120v.

For reference, the 60v on each leg is how American ships are wired and built, everyone else outside of North America uses 220v systems so they're wired 120-120 with no neutral.

Anything that is designed to run 220v either needs to be 120-120 or 240-N, so those lights that were mentioned are expecting a hot leg of 120-240v and a neutral leg of 0v

I'm an electrician on container ships and any ground is a "Bad Thing" out here.

@Jodi: Please, PLEASE for the safety of yourself and your vessel, undo this ASAP! You're going to need to get some serious 8kw transformers involved if you want to run 110v stuff on that boat, either that or start tracking down suppliers for 220v stuff.
 
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Surferdudemi

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240V has less losses due to wiring resistance. 2X voltage, 1/2 amps = 1/4 resistance.

Note that aside from the losses, they use the same amount of POWER, i.e., a given energy source will power them for about the same amount of time as they will use the same Watts at either voltage.
I think that should be 1/4 of the power loss of the 120v case. The resistance does not change. Power is I^2 x R
 

Jodi

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Ummm... that's not how it's supposed to work. What you're doing is dead grounding your system to the hull and dumping current into the hull. This is going to chew any metal you have to rust in no time flat and potentially damage your electrical system & generator if not zap you every time you grab a railing! We just had a ship down for a month because they didn't fix the grounds and it destroyed all the main engine bearings in a 4 story tall engine!

The reason there is no Neutral is because your system is designed to take 120v from L1 and 120v from L2 and provide the 240v that your boat is built to use. If you need 120v for N.American stuff, you need to get transformers involved that will create that Neutral line and/or step it to 60v on each leg to provide 120v.

For reference, the 60v on each leg is how American ships are wired and built, everyone else outside of North America uses 220v systems so they're wired 120-120 with no neutral.

Anything that is designed to run 220v either needs to be 120-120 or 240-N, so those lights that were mentioned are expecting a hot leg of 120-240v and a neutral leg of 0v

I'm an electrician on container ships and any ground is a "Bad Thing" out here.

@Jodi: Please, PLEASE for the safety of yourself and your vessel, undo this ASAP! You're going to need to get some serious 8kw transformers involved if you want to run 110v stuff on that boat, either that or start tracking down suppliers for 220v stuff.
I only wired created 1 outlet for 120V. The light run of 12v
I believe everything being equal I can make the brown wire neutral and change everything on boat to 120V, but I wanted to keep 240V for efficiency. The victron. Inverter would have to change for a dual system or I believe i can use a power switching unit.
 

12VoltInstalls

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The added “efficiency“ of 220V is pretty much not useful to you. There is no real reason to run 220 in any normal personal boat.
That you didn’t manage to zap yourself doesn’t mean it’s safe or that it’s not invisibly so far damaging components.

Check the gauges against expected loads but generally your 240V wire will handle your loads / maybe with a smaller fuse.
 

Short_Shot

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I only wired created 1 outlet for 120V. The light run of 12v
I believe everything being equal I can make the brown wire neutral and change everything on boat to 120V, but I wanted to keep 240V for efficiency. The victron. Inverter would have to change for a dual system or I believe i can use a power switching unit.
Only doing one doesn't change the fact that you absolutely should not have done it at all.

The green wire should never be used in this manner for a whole lot of reasons.

Your only safe bet will be to eliminate all of the non-US standard stuff. Trying to mix these components can and likely will result in injury or death.
 

Rednecktek

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In theory you could replace your generator with a 120v system providing 60v-60v and no neutral, HOWEVER it would be an insane amount of work to do it.

You'd lose half your available power as the breakers installed are sized to the wire. 10amps @ 240v = 2400w, 10a @ 120v = 1200w
You may have to replace your radar/ECDIS/Fathometer/VHF/Gyro/ETC if they won't run on 120v from the factory
You'll have to replace all your light bulbs and nav lights to 120v versions
Any 220v pumps, (water/MSD/hydraulics/steering/etc) will have to be replaced with 110v and new wires run from the MSB to the motors to handle the extra current
You'll have to have it all inspected by USCG at the very least
And so on and so on...

OR you could just get some step-down transformers and use those where needed.
 

12VoltInstalls

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replace all your light bulbs and nav lights to 120v versions
Any 220v pumps, (water/MSD/hydraulics/steering/etc) will have to be replaced with 110v and new wires run from the MSB to the motors to handle the extra

How big is this stinkin boat!!??
 

Rednecktek

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Well, my "little" boats are only 169.7 meters... :)

Still, even smaller craft will have numerous electric motors between bilge pumps, anchor windlass, fresh water, etc. Those will need new wires from the main breaker panel to handle the amperage load of the 120v versions.

More expensive is the electronics like the radar, ECDIS, fathometer, etc that may or may not take a 120v input to run without higher amperages than the wiring is rated for.

As for the nav lights, we're still waiting on LED light bulbs for those, they're a "Marine" socket so a lot of hoops to jump through to find the right socket.

Not that the industry is slow to modernize but my current ship runs our engine control system on Windows NT4...
 
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Supervstech

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The place where running 240VAC pays off the most is on heavy loads. For example, my water pressure pump is about 100 feet from my power center. So I ran 240 out there and wired the pump for 240. I could use smaller wire that way. Same thing for my welder, although it isn't all that far it is a pig for power. If the distance isn't far and the load is small the advantage is less. Since for 120 you only need 2 conductors + ground and for 240 you need 3 conductors + ground you may save a little sticking with 120. However, in general there really is no penalty for using 240.
240V appliances need the same number of conductors as 120V appliances… split phase panels at 240 need more conductors, if ANY circuits require 120V, but a 240V appliance does not need a neutral… just 2 hots and a ground… just like a 120V needs a hot and a neutral and a ground.
Clothes dryers and ranges have 120V components… clock, lightbulb, etc. and so, they need 4 wires, but pure 240V appliances do not.
 

12VoltInstalls

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my "little" boats are only 169.7 meter
Exactly
Unless I missed a post…. We don’t know if Jodi he or she is 28’, 32’, or 100’, sail or diesel. Their navaids, lights, etc could even be 24V or 12V

So by the time I read 240 pump I was like: out of scope! out of scope!
 

boondox

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240V appliances need the same number of conductors as 120V appliances… split phase panels at 240 need more conductors, if ANY circuits require 120V, but a 240V appliance does not need a neutral… just 2 hots and a ground… just like a 120V needs a hot and a neutral and a ground.
Clothes dryers and ranges have 120V components… clock, lightbulb, etc. and so, they need 4 wires, but pure 240V appliances do not.
True, a 240 pump doesn't need the neutral. In my case I wanted 120VAC in the shed. But a question, do they make romex with a red, black and ground only? I don't recall seeing that but it may well exist. I'll look next time I am in the local hardware store and see if they carry such a thing.
 
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