Sunny Boy 4000TL-US-22

[john95]

Why this inverter is listed as 208/240VAC output? Don't we use 120VAC in our houses? I don't see any SMA inverter as having 120VAC output. Any other comparable inverters as this one in the market? Thanks.

[truav8r]

For the same reason your POCO feeds 240V into your house. Your electric panel then serves up 120V or 240V depending on the circuit.

[john95]

For the same reason your POCO feeds 240V into your house. Your electric panel then serves up 120V or 240V depending on the circuit.

It makes it so confusing. The utility company, (don't say POCO), supplies 2 lines of 120v each and one neutral, these 3 lines combined make that 240VAC that must people don't need any way. Who in the world needs 208 VAC? Why the spec any way?

[truav8r]

It makes it so confusing. The utility company, (don't say POCO), supplies 2 lines of 120v each and one neutral, these 3 lines combined make that 240VAC that must people don't need any way. Who in the world needs 208 VAC? Why the spec any way?

What do you mean "most people don't need" 240V ?? Anybody with a well pump, electric dryer, electric range/oven, or electric vehicle would disagree. Not to mention a grid-tied solar system.

If you really find it "confusing" that your electric panel is rated for 240V and grid-tied inverters are rated for 240V, then I'm not sure there's much else we can do for you.

[ButchDeal]

Who in the world needs 208 VAC? Why the spec any way?

208 is any 2 legs of a 3 phase system, which is generally commercial but also in some condos and apartments.

[john95]

What do you mean "most people don't need" 240V ?? Anybody with a well pump, electric dryer, electric range/oven, or electric vehicle would disagree. Not to mention a grid-tied solar system.

My house and all the houses in Los Angeles, CA run on 120VAC. They have the capability to have 240VAC but they don't use it by default they output 120VAC in all outlets. I have an electric car and I don't have a need for 240VAC. 120VAC is good enough. It charges the car just fine.

If you really find it "confusing" that your electric panel is rated for 240V and grid-tied inverters are rated for 240V, then I'm not sure there's much else we can do for you.

Of course it is confusing! It should describe as being 240VAC rated maximum with capabilities of outputting 120VAC & 240VAC.
Also, I asked the question here because obviously I don't know and perhaps one of you guys know the inverter and can give me more detailed explanation about it. However, I don't need you grief, you did not answer my question at this time, so I'll appreciate if you don't answer my questions with your

Mod note: I feel you are being rude. Stop it or I will ban you

[john95]

208 is any 2 legs of a 3 phase system, which is generally commercial but also in some condos and apartments.

So that means 2 connectors for 120VAC and 1 for the neutral? Isn't it?

[inetdog]

So that means 2 connectors for 120VAC and 1 for the neutral? Isn't it?

Absolutely correct.
The neutral is no longer a neutral in the NEC sense once you have taken only two of the three phases of the three phase service to supply a single panel with two hot wires and the neutral from the three phase service.

If you make a scale drawing of two 120V vectors at an angle of 120 degrees to each other you can measure the distance between the two vector heads and see that it is 208V instead of the 240 you get when the two 120V lines are parallel but in exactly opposite directions.
Almost all heating and lighting equipment (and most motors) that are rated for 240V input will work OK, but with reduced performance, on 208V.

The difference is that if you put 15A line to neutral loads on each side of a 120/240 single phase circuit there will be no current in the neutral.
But if you put a 15A load on two hot lines of a 208Y/120 circuit you will also have 15A on the neutral.

This particular inverter is designed to work automatically with a line to line connection in either configuration. Or you could even use three of those inverters to connect to all three line to line combinations of a three phase service.

The reason that the inverter is designed to connect to the higher voltage is that it requires only half (for 240) or a little more than half (for 208) of the current output it would need to generate if you connected only to 120V.

PS: By the way, connecting to both lines allows the SMA inverter to feed either balanced or unbalanced loads in your house with the difference in current between the two legs being supplied by the utility connection and its 120/240V three wire service transformer.

[sensij]

Absolutely correct.
The neutral is no longer a neutral in the NEC sense once you have taken only two of the three phases of the three phase service to supply a single panel with two hot wires and the neutral from the three phase service.

If you make a scale drawing of two 120V vectors at an angle of 120 degrees to each other you can measure the distance between the two vector heads and see that it is 208V instead of the 240 you get when the two 120V lines are parallel but in exactly opposite directions.
Almost all heating and lighting equipment (and most motors) that are rated for 240V input will work OK, but with reduced performance, on 208V.

The difference is that if you put 15A line to neutral loads on each side of a 120/240 single phase circuit there will be no current in the neutral.
But if you put a 15A load on two hot lines of a 208Y/120 circuit you will also have 15A on the neutral.

Just to clarify, single phase line to line loads supplied by two legs of 208Y do not require a neutral, all current flows through the hots as it does when supplied by 240 vac. The 208 volts rms between them is a true 60 hz sine wave alternating around 0 volts... it is true that both legs may have + or - voltage relative to a ground reference (neutral) at any moment in time, but that has no effect on the current flow (unless there is a fault). The only voltage that matters is the instantaneous difference between the lines.

[ButchDeal]

My house and all the houses in Los Angeles, CA run on 120VAC. They have the capability to have 240VAC but they don't use it by default they output 120VAC in all outlets. I have an electric car and I don't have a need for 240VAC. 120VAC is good enough. It charges the car just fine.

Of course it is confusing! It should describe as being 240VAC rated maximum with capabilities of outputting 120VAC & 240VAC.
Also, I asked the question here because obviously I don't know and perhaps one of you guys know the inverter and can give me more detailed explanation about it. However, I don't need you grief, you did not answer my question at this time, so I'll appreciate if you don't answer my questions with your BS. Your are not helpful at all, you are no one, you don't know anything.

They do NOT have the capability of outputing 120V AC. They output 240V AC and the power company balances it to you. There are inverters capable of doing 120V ac, I have one by OutBack with a single 120V inverter and a transformer to get to 240V for my well pump.


I design solar for all over the US and in southern CA I have yet to see a single home with a 120V feed. They are all 240V. Yes your outlets are 120V but your electric stove, air conditioning, hot tub, clothes dryer, etc. are all 240V.

[SunEagle]

208 is any 2 legs of a 3 phase system, which is generally commercial but also in some condos and apartments.

I agree with you. The Utility pole may have a 3 phase 120/208v transformer but can provide only 2 phase legs (208v single phase) to the customers main panel.

The problem with that is keeping the 3 phase transformer balanced by sending a different 208v single phase to 3 different panels.

IMO that is not a good practice for a 3 phase transformer to be unbalanced but maybe SMA may has a design for 3 of those inverters to be used on a 3 phase 208/120v electrical service.

[john95]

Do you guys know what's the difference between the Sunny Boy 3000 TL-US and the 4000 TL-US?

[Naptown]

Do you guys know what's the difference between the Sunny Boy 3000 TL-US and the 4000 TL-US?

One is 3000 watts
The other is 4000 watts

[Naptown]

I agree with you. The Utility pole may have a 3 phase 120/208v transformer but can provide only 2 phase legs (208v single phase) to the customers main panel.

The problem with that is keeping the 3 phase transformer balanced by sending a different 208v single phase to 3 different panels.

IMO that is not a good practice for a 3 phase transformer to be unbalanced but maybe SMA may has a design for 3 of those inverters to be used on a 3 phase 208/120v electrical service.

You almost never see 3 phase in residential. I have seen it exactly once in 35 years. That was in a 8000 square foot house with electric radiant heat and a 1200amp service.
The well pump was rated 50A 208 3 phase.
I could almost guarantee that the service in his house is 240 single phase or split phase which is a different way of saying it

[SunEagle]

You almost never see 3 phase in residential. I have seen it exactly once in 35 years. That was in a 8000 square foot house with electric radiant heat and a 1200amp service.
The well pump was rated 50A 208 3 phase.
I could almost guarantee that the service in his house is 240 single phase or split phase which is a different way of saying it

I agree. It seems that SMA makes single phase inverters rated 208/240V so there must be somewhere the 208v connection can be used. It is probably for a small business or farm which uses 3 phase loads.