Need help with inverter

[Livin4us]

We have been struggling tirelessly with our inverter to get it wired correctly. We have a WFCO t-57r transfer switch. The inverter is a sungold power 4000W. There is no diagram explaining where we connect the power for the inverter to on the transfer switch. So, my question, does it just connect to the shore power in the transfer switch? Any help will really be appreciated. The company can’t even properly answer my questions.

 

[jackiemac]

Hopefully someone can help you out. Welcome to the forum.

 

[Yoshi]

Hi,

I found this. Do you have it?

I connected my inverter to the generator terminals. The shore power is the wire from your shore power plug. Load goes to your AC panel for your branch circuits.

https://www.rvupgradestore.com/v/vspfiles/assets/pdf/T-57-Manual.pdf

 

[Livin4us]

Hopefully someone can help you out. Welcome to the forum.

Thank you Jackie!

 

[Yoshi]

Hi @Lou Schneider , I apologize if I gave incorrect info. . I was thinking the inverter was powered by the coach battery (s) and hard wired into the transfer switch. Then the transfer switch prioritzes either inverter input (when on) or shore power input for the load side. That is how mine works.

Edit; I don't know what happen to the responce I was replying to.

 

[Livin4us]

Hi,

I found this. Do you have it?

I connected my inverter to the generator terminals. The shore power is the wire from your shore power plug. Load goes to your AC panel for your branch circuits.

https://www.rvupgradestore.com/v/vspfiles/assets/pdf/T-57-Manual.pdf

View attachment 162340

Thank you, we have a

Hi @Lou Schneider , I apologize if I gave incorrect info. . I was thinking the inverter was powered by the coach battery (s) and hard wired into the transfer switch. Then the transfer switch prioritzes either inverter input (when on) or shore power input for the load side. That is how mine works.

Ok so, inverter output goes to shorepower input in the transfer switch and output from transfer switch to input of inverter. My transfer switch has inputs for shorepower, and generator. Priority is to generator. So do I hook up the inverter with the shore power?

 

[Livin4us]

@Lou Schneider I believe you have answered my question. My inverter is a sungold power split phase 4000w inverter. It has its own transfer switch in it. So I can hook it up on the same terminals as our shore power, making it loop through the inverter? Is that correct?

 

[Lou Schneider]

If you put it on the shore power input to the switch, you won't be able to charge the batteries from the generator since it won't be able to supply voltage to the charger portion of the inverter. I'd put it on the output of the existing transfer switch so both the generator or shore power can supply voltage to it.

 

[Gary RV_Wizard]

It depends on what you are trying to achieve by using the inverter. There is no need to hook the inverter to the shore/generator transfer switch at all. In fact, since it has its own internal transfer switch, the most effective method would be to have the output from the shore/generator transfer feed IN to the inverter's 120v input and the inverter output feed into the load center (breaker box) or some subset it. That way the inverter passes thru power from shore or generator when available and inverts from battery when there is no external power.

Note: You probably also have a separate converter/charger for the house batteries. Make sure to disable that charger when the inverter is operating from battery power. That avoids a "power loop" in which the inverter draws power from the batteries to run the charger to put power back in the batteries. That loop would quickly deplete the batteries.

 

[Livin4us]

If you put it on the shore power input to the switch, you won't be able to charge the batteries from the generator since it won't be able to supply voltage to the charger portion of the inverter. I'd put it on the output of the existing transfer switch so both the generator or shore power can supply voltage to it.

 

[Livin4us]

So we should wire from the output of the inverter to the control switch input on the transfer switch, then output control switch to input inverter?

 

[Gary RV_Wizard]

So we should wire from the output of the inverter to the control switch input on the transfer switch, then output control switch to input inverter?

Not sure I understand what you are proposing, but my gut says no.

What is the "control switch input"? The RV auto transfer switches I'm familiar with don't have separate control inputs. Instead they sense which of the two power sources has adequate live voltage and switch to that one. If both sources have power, one is given priority over the other. in an RV, usually the generator side has priority over shore power.

Please explain what is currently wired to that auto transfer switch (ATS), e.g. is it the typical shore power cord plus a generator? And is it a 30A/120v ATS or a 50A/240v ATS?

Also, does the Sungold 4000 have a charger built-in? Perhaps this model? If so, you can eliminate the existing converter/charger and let the new inverter handle charging as well as inverting.

Are you expecting everything in the RV to work from the inverter the same as it does from shore or genset power? That's not going to happen for practical reasons, but it can be wired such that it could work that way if you have enough battery power available to meet demand. A 4000W inverter draws around 350A at full load, so you need a huge battery bank to come even close to that amount for more than a few seconds.

 

[Yoshi]

Hi @Livin4us ,

As a suggestion, it maybe helpful if you can draw up your proposed wiring diagram for your shore power, inverter and transfer switch. It may help to follow your plan. Also, do you have a generator in addition to the inverter.

Thank you,

 

[Livin4us]

Not sure I understand what you are proposing, but my gut says no.

What is the "control switch input"? The RV auto transfer switches I'm familiar with don't have separate control inputs. Instead they sense which of the two power sources has adequate live voltage and switch to that one. If both sources have power, one is given priority over the other. in an RV, usually the generator side has priority over shore power.

Please explain what is currently wired to that auto transfer switch (ATS), e.g. is it the typical shore power cord plus a generator? And is it a 30A/120v ATS or a 50A/240v ATS?

Also, does the Sungold 4000 have a charger built-in? Perhaps this model? If so, you can eliminate the existing converter/charger and let the new inverter handle charging as well as inverting.

Are you expecting everything in the RV to work from the inverter the same as it does from shore or genset power? That's not going to happen for practical reasons, but it can be wired such that it could work that way if you have enough battery power available to meet demand. A 4000W inverter draws around 350A at full load, so you need a huge battery bank to come even close to that amount for more than a few seconds.

Ok so we have a WFCO t-57r transfer switch. It’s hooked up to the generator as primary, shore power is secondary, and the control panel whose output goes to our breaker panel 120/240. The inverter is a split phase and we would like to be able to run anything, but we know not at the same time. We have solar and 695Ah total battery storage. My understanding is I need to create a loop of power between the inverter and transfer switch. I have already deleted the charger on the trailer. The inverter has a charger, transfer switch, and can prioritize battery power over shore power using DIP switches.

 

[HueyPilotVN]

Lou Schneider helped me design my Solar power system.

My invertor gets the AC input from a point just after the output of the transfer switch where it goes thru a circuit breaker before it enters the invertor. The AC automatically, passes through when there is AC power from either the shore power connection or the generator.

The main power panel is supplied with AC from the invertor only, either by the pass thru AC or the battery supplied AC output from the invertor.

This is not the normal setup, however with 1,200 Amp hours of Lithium I can use the batteries as an alternate 110 volt power source.

The original 12 volt system is completely independent of the main solar system and therefore it can be charged by the convertor charger as if it were powered by any AC source without any closed loop considerations.

I have not connected to shore power since the system became operational and it mostly stays at full SOC due to 1,600 watts of solar panels.

When the heat of summer comes, we shall see how long the Air Conditioner will run on only the batteries supplied by solar.

 

[Livin4us]

It depends on what you are trying to achieve by using the inverter. There is no need to hook the inverter to the shore/generator transfer switch at all. In fact, since it has its own internal transfer switch, the most effective method would be to have the output from the shore/generator transfer feed IN to the inverter's 120v input and the inverter output feed into the load center (breaker box) or some subset it. That way the inverter passes thru power from shore or generator when available and inverts from battery when there is no external power.

Note: You probably also have a separate converter/charger for the house batteries. Make sure to disable that charger when the inverter is operating from battery power. That avoids a "power loop" in which the inverter draws power from the batteries to run the charger to put power back in the batteries. That loop would quickly deplete the batteries.

We tried this and it didn’t work. We took the feed that went from the control panel output to the input of the inverter and from the output of the inverter to the sub panel. The generator would not charge the batteries at all, the inverter kept turning off when it should have been transferring power, it was all a mess. This is a 120/240v 4000w split phase inverter.

 

[Gary RV_Wizard]

My understanding is I need to create a loop of power between the inverter and transfer switch.

I can't imagine why.

I see nothing in the Sunpower 4000 spec about 240v power or split phase.

Inverter Output:
*Continuous Output Power: 4000W
*Surge Rating: 12000W (20 Seconds)
*AC Output: 120VAC
*AC Input: 120VAC
*Output Wave: Pure Sine Wave (bypass mode)
*Typical Transfer Time: 10ms (MAX)
*Nominal Efficiency: >88%

The generator does NOT charge batteries itself. If merely provides 120v power to whatever charger is installed, in this case the Sunpower. You have to wire the Sunpower DC output to the battery bank to get charging.

If you have a 50A/240v ATS, it has two hots and a neutral at each input & output. The Sunpower has only a single hot (line) terminal, so I don't see how you can wire pass-thru for full power to the main load center.
You mentioned a subpanel? Where is that?

 

[Livin4us]

Lou Schneider helped me design my Solar power system.

My invertor gets the AC input from a point just after the output of the transfer switch where it goes thru a circuit breaker before it enters the invertor. The AC passes through when there is AC power from either the shore power connection or the generator.

The main power panel is supplied with AC from either the pass thru AC or the battery supplied AC output from the invertor.

This is not the normal setup, however with 1,200 Amp hours of Lithium I can use the batteries as an alternate 110 volt power source.

The original 12 volt system is completely independent of the main solar system and therefore it can be charged by the convertor charger as if it were powered by any AC source without any closed loop considerations.

I have not connected to shore power since the system became operational and it mostly stays at full SOC due to 1.600 watts of solar panels.

When the heat of summer comes, we shall see how long the Air Conditioner will run on only the batteries supplied by solar.

@Lou Schneider i am getting more confused. These are my diagrams.

 

[Livin4us]

I can't imagine why.

I see nothing in the Sunpower 4000 spec about 240v power or split phase.


The generator does NOT charge batteries itself. If merely provides 120v power to whatever charger is installed, in this case the Sunpower. You have to wire the Sunpower DC output to the battery bank to get charging.

If you have a 50A/240v ATS, it has two hots and a neutral at each input & output. The Sunpower has only a single hot (line) terminal, so I don't see how you can wire pass-thru for full power to the main load center.
You mentioned a subpanel? Where is that?

 

[Livin4us]

Here are my diagrams for the inverter and the transfer switch