Frequency changed

[CRenner]

I know I bought the wrong inverter but I can't afford another, so I need to make this work.

Since I want to be totally off grid at times, this is what I hooked up:
My batteries feed the inverter which feeds the main panel through the AC Output, and that should start the Enphase.
When I turn this on, the inverter showed discharging the batteries at about 10-12 amps for the first 5 minutes.
Then the discharge went to zero but it never charged. Instead, the battery voltage climbed to 56 in about two minutes and the Enphase shut off and the discharge resumed.
I then connected a 12/3 cable from the main panel back to the AC Input on the inverter.
With this connected the AC Output was 60hz but the AC Input showed 52hz and the Enphase never started.

Why would the hertz change?

 

[sunshine_eggo]

I know I bought the wrong inverter but I can't afford another, so I need to make this work.

If you did not purchase an inverter capable of AC coupling, you can't make it work. Period.

The AC coupled grid forming inverter must exceed the power output of your Enphase array.

Sounds like you need to remove the enphase and simply wire the panels to the MPPT.

Hopefully, you didn't damage the Sungoldpower unit.

 

[DIYrich]

I know I bought the wrong inverter but I can't afford another, so I need to make this work.

Since I want to be totally off grid at times, this is what I hooked up:
My batteries feed the inverter which feeds the main panel through the AC Output, and that should start the Enphase.
When I turn this on, the inverter showed discharging the batteries at about 10-12 amps for the first 5 minutes.

Enphase may have a delay in detecting AC power before it starts producing.

Then the discharge went to zero but it never charged. Instead, the battery voltage climbed to 56 in about two minutes and the Enphase shut off and the discharge resumed.

Were batteries fully charged? 56v is about full.

If you are off grid, there needs to be some headroom in the battery for the AC PV (enphase) to be turned on. It needs the buffer incase a large load shuts off, and the power has to go somewhere (the battery).

I then connected a 12/3 cable from the main panel back to the AC Input on the inverter.

What? Main panel connected to Input and Output of the Inverter?

With this connected the AC Output was 60hz but the AC Input showed 52hz and the Enphase never started.

Why would the hertz change?

Inverter uses frequency shifting to control the Enphase. However, it shifts frequency up to turn it off. 52hz seems more like a 50hz nominal system.

 

[timselectric]

I know I bought the wrong inverter but I can't afford another, so I need to make this work.

Since I want to be totally off grid at times, this is what I hooked up:
My batteries feed the inverter which feeds the main panel through the AC Output, and that should start the Enphase.
When I turn this on, the inverter showed discharging the batteries at about 10-12 amps for the first 5 minutes.
Then the discharge went to zero but it never charged. Instead, the battery voltage climbed to 56 in about two minutes and the Enphase shut off and the discharge resumed.
I then connected a 12/3 cable from the main panel back to the AC Input on the inverter.
With this connected the AC Output was 60hz but the AC Input showed 52hz and the Enphase never started.

Why would the hertz change?

Several scary statements.
You can't force incompatible equipment to work.
Your only saving grace is that the equipment is smart enough to keep you from burning your house down. (So far)

 

[CRenner]

If you did not purchase an inverter capable of AC coupling, you can't make it work. Period.

The AC coupled grid forming inverter must exceed the power output of your Enphase array.

Sounds like you need to remove the enphase and simply wire the panels to the MPPT.

Hopefully, you didn't damage the Sungoldpower unit.

The IP6048 was sold as having the ability to AC Couple. It has a setting that allows AC Coupling saying the AC Out will be bidirectional.
The Enphase can produce 22 amps, with some used by the house load before feeding back to the inverter.
I had hoped that this would charge the batteries.

Enphase is suppose to have a 5 minute delay to see if the grid is stable before starting.
The batteries were at 51 volts when I started this.

This inverter does not frequency shift. That is part of the problem.

Do I need a wall charger?

 

[sunshine_eggo]

This inverter does not frequency shift. That is part of the problem.

Then it can't be AC coupled.

Do I need a wall charger?

Maybe. I don't even understand the context of this question.

What's stopping you from pulling the micro inverters off the panels and wiring the panels to the MPPT?

 

[CRenner]

I guess cost and difficulty.
My array is ground mounted so the wires are buried underground. I can't use the same cable so would have to dig it all up.
I would have to buy optimizers and sell the IQ8+'s.

 

[timselectric]

The cost should be minimal. Because you are just removing the micro inverters.
The wiring should not need to be replaced. Unless you have a very low voltage SCC.
Difficulty should be low, because it's a ground mount. You can access the wiring without removing the panels.
You don't need optimizers, unless the location is horrible with shading.

 

[CRenner]

I was just looking in the Inverters for Sale section and saw no Enphase stuff.
Is this forum the wrong place to sell this?
They are about 6 months old, any idea what I could sell them for?

 

[hwy17]

Is this forum the wrong place to sell this?

You can sell it here but there is very little interest in grid tied hardware.

They are about 6 months old, any idea what I could sell them for?

Up to half price on craigslist. You're up against the fact that anyone can get 30% tax credit on new hardware.

 

[sunshine_eggo]

The IP6048 appears to allow up to 550Voc (need to allow for cold temp margins) on the PV, so the wiring losses will be LESS than the enphase if suitably configured.

The only issue I see is that you may need a second pair of conductors if you only have one pair. You'll need a pair for each MPPT.

 

[timselectric]

The IP6048 appears to allow up to 550Voc (need to allow for cold temp margins) on the PV, so the wiring losses will be LESS than the enphase if suitably configured.

The only issue I see is that you may need a second pair of conductors if you only have one pair. You'll need a pair for each MPPT.

I don’t think it would be a problem.
The Enphase system is running at 240v. And most likely 20a circuits.
With the increased voltage on DC, the existing conductors should be more than adequate.

 

[CRenner]

I have 18 400 watt panels. I don't know the voltage. I can look tonight.
The micro inverters are 1.21 amps each, so that is 21.78. Would that be a 20 or 30a breaker?

 

[sunshine_eggo]

I have 18 400 watt panels. I don't know the voltage. I can look tonight.

You may actually get more out of your panels going direct to MPPT. Microinverters are often over-paneled a bit.

The micro inverters are 1.21 amps each, so that is 21.78. Would that be a 20 or 30a breaker?

1.25X current, round up.

20A breaker on a circuit needing 21.78A means... you'd trip the breaker.

None of this matters now as you need to rewire, and your panel specs will now dictate requirements.

What gauge and how many wires do you have between the array and the inverter?

 

[CRenner]

The two arrays of 9 are combined at the rack and only one set is run underground.

 

[CRenner]

I don't know the gauge.
I can look tonight.

 

[timselectric]

The two arrays of 9 are combined at the rack and only one set is run underground.

It should be more than sufficient.
Need the specs and conductor size to confirm.

 

[CRenner]

When you say specs, is that of the panel?
Voc = 45.3

 

[timselectric]

When you say specs, is that of the panel?
Voc = 45.3

Yes,
And the SCC.
All specs for both.

 

[sunshine_eggo]

Need

Voc
Vmp
Isc
Imp


Pretty sure the MPPT is up to 550Voc, 15A Imp and 21A Isc.