Will I provide too much power with this setup?

[Bloooop]

I'm installing a 24,000 BTU AC/DC Hybrid Solar Air conditioner and can't get it to work optimally, so I'm wondering if increasing to a 4s2p from a 3s2p will cause any damage.

Here's the data

Solar AC Unit Requirements:

• Max. Solar Power Input - 3KW
• Max Input Solar DC Voltage - DC 380V
• MPPT Voltage range - DC 100-360V
• Max. Short circuit Current - DC 15A

My Panel Details at STC: 6-8 JA solar 415W (The only thing I could get)

• Pmax - 415
• VOC - 50.41
• VMP - 42.18
• ISC - 10.51
• IMP - 9.84

Details at NOCT

• Pmax - 314
• VOC - 47.16
• Vmp - 39.41
• ISC - 8.41
• Imp - 7.97

The unit requires 1800 W to run at T1 and 1946W at T3 with a Rated Power input(Max) of 2520 W.

The first setup I tried was a series of 6 panels, but that didn't even get the compressor running without shutting off. I assumed I wasn't providing enough amps to power it up fully.

I then opted for a 3s2p which got it to run at 26 degrees C in peak sun conditions since now I'd be giving it close to 20A and 2520W, which should've been perfect. However, that still didn't work. So my assumption is the unit is only working off 15A, which would give it 1890W instead of 2520W.

Now I'm considering doing a 4S2P as that would give it the actual 2,520W at 15A? However, based on the data, wouldn't I be giving it more than 3KW and damage it if I do that?

 

[BradCagle]

What air conditioner is this? You're running it only on solar, no batteries or grid anywhere? If so that seems impractical.

 

[Bloooop]

It's a Superen Hybrid AC/DC Air conditioner with direct PV inputs built in. It can be run directly by the panels, connected to the grid, or both simultaneously.

The manufacturers recommend 7-9 300W panels, each providing 30V connected in Series, but that doesn't seem to work in my case as I've connected up to 7 of the panels mentioned in series, but it doesn't even turn the compressor on for more than 30 seconds.

That's why I ended up going with a 3S2P setup, and it's still not working efficiently.

 

[OffGridInTheCity]

I'm installing a 24,000 BTU AC/DC Hybrid Solar Air conditioner and can't get it to work optimally, so I'm wondering if increasing to a 4s2p from a 3s2p will cause any damage.

Here's the data

Solar AC Unit Requirements:

• Max. Solar Power Input - 3KW
• Max Input Solar DC Voltage - DC 380V
• MPPT Voltage range - DC 100-360V
• Max. Short circuit Current - DC 15A

My Panel Details at STC: 6-8 JA solar 415W (The only thing I could get)

• Pmax - 415
• VOC - 50.41
• VMP - 42.18
• ISC - 10.51
• IMP - 9.84

Details at NOCT

• Pmax - 314
• VOC - 47.16
• Vmp - 39.41
• ISC - 8.41
• Imp - 7.97

The unit requires 1800 W to run at T1 and 1946W at T3 with a Rated Power input(Max) of 2520 W.

The first setup I tried was a series of 6 panels, but that didn't even get the compressor running without shutting off. I assumed I wasn't providing enough amps to power it up fully.

6s would be 6panels * 42.81v = 257v @ 9.84a.
257v * 9.84a = 2529watts.
And that would 100% from 6s panels - not likely. So it's no wonder there wasn't enough power to run it.

I then opted for a 3s2p which got it to run at 26 degrees C in peak sun conditions since now I'd be giving it close to 20A and 2520W, which should've been perfect. However, that still didn't work. So my assumption is the unit is only working off 15A, which would give it 1890W instead of 2520W.

However you do 6s1p or 3s2p - its just not enough power for most of the day based on the numbers here.

Now I'm considering doing a 4S2P as that would give it the actual 2,520W at 15A? However, based on the data, wouldn't I be giving it more than 3KW and damage it if I do that?

4s = 4 * 42.81v = 171v and 2p = 2 x 9.84a = 19.7a.
171v * 19.7a = 3369w @ 100%.
But again, this is 100% PV. My own panels range from 90% at 'perfect conditions' to 65% a lot of the day, up/down in power, due to many reasons.

60% of 3369w = 2021w.... Just not enough. I agree that 60% is arbitrary based on my own operational monitoring... so maybe 70% or 50% - a lot of factors.

But personally, I'd recommend at least 10 panels - 5s2p - for a reasonable shot at running things for 8hrs a day. I'd also recommend monitoring what you're panels produce thru the day to get a correct idea of what you're producing - this will ultimately tell you what you need.

 

[Mattb4]

You will not overpower it. Consider if you were running the AC on utility power. The utility power is considerably higher amount of watts available and yet your appliances do not get overloaded. On solar power you only draw watts depending on load. However it sounds as if you have insufficient amount of power to run your AC from solar.

 

[Bloooop]

But personally, I'd recommend at least 10 panels - 5s2p - for a reasonable shot at running things for 8hrs a day.

Ok, so you're saying that even if I used more panels based on average or even peak daily conditions, I likely won't be producing enough power to damage the unit by exceeding the 3KW?

Also, I'm in the tropics (Jamaica) to be specific, and the temperatures here are constant all year (not including cloud and rain conditions)

 

[TomC4306]

wouldn't I be giving it more than 3KW and damage it if I do that?

Watts are not 'pushed' from the solar panels. They are 'pulled' by the load.
You could connect 10000 watts of panels but the load (air conditioner) will only 'draw' what it needs.

 

[BradCagle]

Yeah, PV panels rarely hit the rated wattage. I usually see avg 75% of the rated.

Still even if you get enough PV on this thing, I think you'll run into problems on days that aren't 100% clear. Think those hot, but chunky clouds rolling by days.

 

[Bloooop]

Got it. Thank you guys for the clarifications! I'll give it a go and if needed add 2 more panels.

 

[AJB]

?

 

[AJB]

Got it. Thank you guys for the clarifications! I'll give it a go and if needed add 2 more panels.

Wondering how those units are working out for you?

 

[Bloooop]

Update

I ended up having to change the 24k unit as it didn't work regardless of the configuration I tried. So I reached out to the company that sold it to me and they replaced it with a different brand called "Solair" which works flawlessly with 7 415w panels connected in series.

The 12k unit works with 4-5 panels fine if I'm getting clear skies but as soon as I a cloud passes anywhere near the compressor goes off while the Solair unit stays own even with the dip in solar power.

Takeaway, the brand matters.

 

[AJB]

It sounds like your seller took care of you, glad to hear that. I also have a 24k unit and it works better then expected, even on half the recommended solar. I plan on getting myself a few more for Christmas.