EG4 24k hybrid in grid shared mode does not see solar panels

[allinson]

Solar array not detected by unit. Unit is EG4 24k hybrid and connected to the grid and solar panels. Solar array connected to factory installed MC4 plugs on the unit and array is putting out 135 vDC. EG4 unit does not see the solar panels. EG4 is working fine using grid power but doesn’t see the solar input. Could use some help.

 

[sunshine_eggo]

IMHO, your array voltage is too low to power the unit at high demand. Yes, it says 90V min, but it also says 12A max from PV, so you're limited to about 1300W output from the array, and that unit can easily draw > 2000W.

Note the EER rating of 11.7. That means at 24000BTU/h output, you need 24000/11.7 = 2051W of PV power, and you can't deliver that with your low voltage array.

 

[EG4_Jarrett]

Solar array not detected by unit. Unit is EG4 24k hybrid and connected to the grid and solar panels. Solar array connected to factory installed MC4 plugs on the unit and array is putting out 135 vDC. EG4 unit does not see the solar panels. EG4 is working fine using grid power but doesn’t see the solar input. Could use some help.

What orientation are your panels in (how many in series/parallel), and what are their VOC and ISC?

 

[sunshine_eggo]

Now that I look at it more closely, that's an Isc limit, so the unit can't even pull 12A from the array - closer to 10A

That means your Vmp needs to be close to 300V to ensure you have enough power to run the unit at full load.

In looking at these specifications, I'm deeply disappointed with this unit's PV capability. It's pretty pathetic. For a temperature margin, you need to have Voc down around 315V. That puts your Vmp down around 252Vmp. With about 10A (maybe 11A) of actual draw from the array, that puts you at about 2600W max theoretical array. Unfortunately with hot temperature effects on PV voltage, you're going to be closer to 227Vmp. At that level, if you're not pumping 10-11A (1000W/m^2), you can't supply the needed power to the unit to run at full blast.

I was seriously considering this unit with the idea that I could over-panel it for extended high load running from PV from like 10a-2p. Now that I see the PV capabilities are so marginal, I can't consider the two ton unit AT ALL. It's PV capabilities are at the minimum.

This is a crap design. VERY disappointing. Going to have to look to other options.

OP, sorry you got suckered.

 

[allinson]

Excellent information.
I am running unit in shared mode with AC limiter enabled. I have Emporium monitoring system monitoring grid power consumption for unit and the EG4 Phone app shows that peak grid watts of 1000. So what I expected to be able to see is a balance between solar and grid on the EG4 app … however all I see on the app is grid demand even though 135 vDC is available from solar panels.

 

[DaveF]

View attachment 221228

Now that I look at it more closely, that's an Isc limit, so the unit can't even pull 12A from the array - closer to 10A

That means your Vmp needs to be close to 300V to ensure you have enough power to run the unit at full load.

In looking at these specifications, I'm deeply disappointed with this unit's PV capability. It's pretty pathetic. For a temperature margin, you need to have Voc down around 315V. That puts your Vmp down around 252Vmp. With about 10A (maybe 11A) of actual draw from the array, that puts you at about 2600W max theoretical array. Unfortunately with hot temperature effects on PV voltage, you're going to be closer to 227Vmp. At that level, if you're not pumping 10-11A (1000W/m^2), you can't supply the needed power to the unit to run at full blast.

I was seriously considering this unit with the idea that I could over-panel it for extended high load running from PV from like 10a-2p. Now that I see the PV capabilities are so marginal, I can't consider the two ton unit AT ALL. It's PV capabilities are at the minimum.

This is a crap design. VERY disappointing. Going to have to look to other options.

OP, sorry you got suckered.

Thanks for highlighting the crucial calculation to make when looking at these specs.

I just installed the 12K unit, and if my calculations are correct my 1800W array should have enough oomph to output the full 13k BTUs under good illumination.

13K BTU needs 13,000/13.04 BTU/W = 997W

Nominal output (measured) for my system (33.3Vmp) would be
220V * 10amp * 13.04BTU/W = 28,688 BTU

Now I'm glad I bought the smaller unit!