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Hannes Bester

Solar configuration

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14 hours ago, WayneSi said:

I put my panels on top of my garage as there is no trees. But I put them all flat. Is that a problem although it gets full sunlight till 5pm as photo is showing.

The end of all 4 string seems to be in shade in the photo.

Placing the panels flat means you get worse production in winter when you need the most from them.

Those panels seem to be touching end to end; there should be a gap in both directions (using T clamps), I believe.

The panels seem very close to the garage roof where they will get quite hot. Are there rails under there? I've seen a set of SolarPower panels (a top of the line expensive brand) get ruined by bolting them directly to a metal roof. They need ventilation under them.

14 hours ago, WayneSi said:

Also have a look at new setting as it came back from supplier and think they maybe did a firmware upgrade.

No, 72.70 is not recent firmware. You could update to patched firmware version 73.00e. That will fix the premature float bugs and adds a few other neat features.

14 hours ago, WayneSi said:

We did a V test on all 4 strings separately by pulling all the fuses back.. And all comes up with 125v separately and then push all fuses back and the main comes to 125V.

As has already been noted, open circuit voltage doesn't fully test the panels. I suggest the following.

During the day with at least reasonable sunshine, preferably no clouds for the next ten minutes, with the battery not full, or with a moderate load:

  • Use the Schneider breaker to disconnect all PV (switch it to off).
  • Pull (disconnect) all fuses except for one, say PV1.
  • Reconnect the Schneider breaker (turn it on). Wait a minute or so for PV power to settle. Record the PV power.
  • Connect another PV breaker. Wait a few seconds, and record the PV power.
  • Repeat until you have all 4 fuses in.

Let us see the results. Suppose you see 200, 1200, 1400, 2000 W. Then you can tell that string 2 is doing most of the work (1000 W), and strings 1, 3, and 4 need work (contributing 200, 200, and 600 W respectively).

It might be worth repeating the experiment, doing the panels in the reverse order. That's because there might be something else limiting how much PV power you can use, and it's a good "sanity check" that you are getting reasonably repeatable results.

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8 hours ago, WayneSi said:

So I have another fuse open pv+5 and pv-5 . Can I add another 3 x 330watt  in series to this last row in my fuse box. Will that increase it to over 2 kw.

You should not need to resort to this. That would be 5 kW nominal of panels; if they were working, it would be too much for your inverter, and the overshoots could damage something.

Let's first try and get the panels you have working better.

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5 hours ago, Coulomb said:

The end of all 4 string seems to be in shade in the photo.

Placing the panels flat means you get worse production in winter when you need the most from them.

Those panels seem to be touching end to end; there should be a gap in both directions (using T clamps), I believe.

The panels seem very close to the garage roof where they will get quite hot. Are there rails under there? I've seen a set of SolarPower panels (a top of the line expensive brand) get ruined by bolting them directly to a metal roof. They need ventilation under them.

No, 72.70 is not recent firmware. You could update to patched firmware version 73.00e. That will fix the premature float bugs and adds a few other neat features.

As has already been noted, open circuit voltage doesn't fully test the panels. I suggest the following.

During the day with at least reasonable sunshine, preferably no clouds for the next ten minutes, with the battery not full, or with a moderate load:

  • Use the Schneider breaker to disconnect all PV (switch it to off).
  • Pull (disconnect) all fuses except for one, say PV1.
  • Reconnect the Schneider breaker (turn it on). Wait a minute or so for PV power to settle. Record the PV power.
  • Connect another PV breaker. Wait a few seconds, and record the PV power.
  • Repeat until you have all 4 fuses in.

Let us see the results. Suppose you see 200, 1200, 1400, 2000 W. Then you can tell that string 2 is doing most of the work (1000 W), and strings 1, 3, and 4 need work (contributing 200, 200, and 600 W respectively).

It might be worth repeating the experiment, doing the panels in the reverse order. That's because there might be something else limiting how much PV power you can use, and it's a good "sanity check" that you are getting reasonably repeatable results.

Hi There

I am using the aluminium T clamps between all the panels with a 3 meter metal rail bar where the clamps slides in. So there is enough space under for air to move thru.

Can i upgrade my model to this version 73.00e as it ses below power factor of 1.0 (5 kW / 5 kVA), and look at my model.

Note: This firmware is only compatible with the 48 V models that have a single low-voltage MPPT and a power factor of 0.8 (4 kW / 5 kVA). i.e. the older PIP-4048MS or Axpert MKS 5K-48 that is no longer manufactured, or their equivalent. It is not compatible with those having dual or triple MPPTs or a power factor of 1.0 (5 kW / 5 kVA), or a maximum PV array open circuit voltage greater than 145 V DC

 So i did the test now under 2 kw load and found you were correct. look below.

PV1 string 170 watt

Pv2 string 380 watt

Pv3 string 381 watt

Pv4 string 381 watt

Now i need to find out if its only 1 in the string or all 3 that is faulty. Going up the roof after lunch . Will let you know.

Thanks alot for all your help .

Wayne

20200508_141424_resized.jpg

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11 hours ago, Coulomb said:

Let's first try and get the panels you have working better.

I agree. As calculated earlier I would expect at least 60% worst case scenario due to the lower winter sun and the angle. There appears to be more going on here.

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Posted (edited)
On 2020/05/17 at 9:58 PM, WayneSi said:

I am using the aluminium T clamps between all the panels with a 3 meter metal rail bar where the clamps slides in. So there is enough space under for air to move thru.

The clamping seems highly unconventional to me. The rails should be held off the roof with suitable stands, and the rails should run parallel to the short sides of the panels. It looks to me that you have run them parallel to the long sides. [ Edit: from the photo below, I see that you have that part right. ] The panels should end up about 100 mm above the tops of the roof. Maybe it's the photo, but it seems a lot closer to the roof to me.

Quote

Can i upgrade my model to this version 73.00e as it ses below power factor of 1.0 (5 kW / 5 kVA), and look at my model.

I based this advice on the fact that you have main firmware version 72.70 now. Perhaps this is what happened: the relatively new (Jan 2019) PF1.0 inverter came with main firmware version 74.40 or so, and someone along the chain thought that 72.70 would be an update. So now you actually have a PF0.8 machine; it won't deliver more than 4 kW for more than a few seconds. So in fact, you should update to patched firmware version 74.40e, though you should check that you don't have a 64 V model (check setting 26; try to get the setting up to higher than 58.4 V, but use escape to cancel instead of enter to accept). 

Quote

PV1 string 170 watt

Pv2 string 380 watt

Pv3 string 381 watt

Pv4 string 381 watt

Now i need to find out if its only 1 in the string or all 3 that is faulty. Going up the roof after lunch . Will let you know.

It looks like you are on your way to figuring this out. My guess is that whatever is affecting string 1 is also affecting the others, just to a lesser degree. 

Edited by Coulomb

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9 hours ago, Coulomb said:

The clamping seems highly unconventional to me. The rails should be held off the roof with suitable stands, and the rails should run parallel to the short sides of the panels. It looks to me that you have run them parallel to the long sides. The panels should end up about 100 mm above the tops of the roof. Maybe it's the photo, but it seems a lot closer to the roof to me.

I based this advice on the fact that you have main firmware version 72.70 now. Perhaps this is what happened: the relatively new (Jan 2019) PF1.0 inverter came with main firmware version 74.40 or so, and someone along the chain thought that 72.70 would be an update. So now you actually have a PF0.8 machine; it won't deliver more than 4 kW for more than a few seconds. So in fact, you should update to patched firmware version 74.40e, though you should check that you don't have a 64 V model (check setting 26; try to get the setting up to higher than 58.4 V, but use escape to cancel instead of enter to accept). 

It looks like you are on your way to figuring this out. My guess is that whatever is affecting string 1 is also affecting the others, just to a lesser degree. 

Hi There

 

Here is a pic of how i mounted the panels..

 

I found 1 x panel faulty. Checked all cables and re crimped it.

 

With all 3 x in series =  It gives 140 watt

With 2 x good ones = it gives 330 watt

1 x good and 1 x bad = 140 watts

 

So the bad one brings all 3 down to its level. Will come thru now and drop off the bad one.

Going to take the one back to supplier now. Also waiting to confirm which firmware i must use by supplier rather to be sure .

 

Thanks Wayne

 

 

20200518_104508_resized.jpg

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14 hours ago, Coulomb said:

The clamping seems highly unconventional to me.

There's at least two things wrong with that.

The first is that you never mount stuff in the valley of a corrugated sheet, because 1) water will gather there and cause rust, and 2) it is more prone to leaking. Always mount stuff on the ridge (if you must), because water flows away from there. Also, drill or punch the hole from below (if you can!) because it tends to flare outwards, which again tends to block water rather than catch it. (Source: almost being klapped once by my father after placing a bolt in the valley... "klapped" means slapped for the foreigners).

The second is that I suspect you're too close to the roof sheets. You want to be 100mm away so that there is a large air envelope (which actually insulates against heat transfer) and so they can breathe.

So if you do take the module back to the supplier... don't tell them you technically voided the warranty 🙂

 

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8 hours ago, plonkster said:

There's at least two things wrong with that.

I agree with @plonkster's concerns; you need about four times the clearance under the panels that you have. But I would add that the rail appears to be galvanised steel. The sawn end appears to be rusting slightly already. So there is the longevity concern.

But also, the clamps and frame are presumably aluminium, and the bolts hopefully stainless steel. This will create a dissimilar metal problem, and you may end up with corrosion.

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10 hours ago, Coulomb said:

I agree with @plonkster's concerns; you need about four times the clearance under the panels that you have. But I would add that the rail appears to be galvanised steel. The sawn end appears to be rusting slightly already. So there is the longevity concern.

But also, the clamps and frame are presumably aluminium, and the bolts hopefully stainless steel. This will create a dissimilar metal problem, and you may end up with corrosion.

Hi There

Thanks for that. I did the firmware update this morning. All went well.

Supplier also swopped my panel out today. But it looks almost the same. better than 140 watt but the sun is more clear today.

I think the next best thing is to lift the panels and get it out of the shade.

 

PV1 = 280 watts

PV2-  440 watts

PV3 = 440 watts

PV4-  440 watts

Thanks Wayne

20200519_104949_resized.jpg

20200519_104953_resized.jpg

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49 minutes ago, WayneSi said:

Thanks for that. I did the firmware update this morning. All went well.

Well done.

49 minutes ago, WayneSi said:

Supplier also swopped my panel out today. But it looks almost the same. better than 140 watt but the sun is more clear today.

I think the next best thing is to lift the panels and get it out of the shade.

Perhaps just unclamp the one that got replaced, which we're suspecting of having the most shade, and move it temporarily into such a position that it gets full sun and perhaps is pointing more towards the sun (as long as that doesn't shade other panels, or at least not string 4, so you have something to compare it to). Hopefully you can do that without having to re-wire anything. Then see how string 1 compares with string 4 after that. Then at least you'll know if it's a shading issue, or something else (I can't think what else it might be off hand, but still).

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22 hours ago, Coulomb said:

Well done.

Perhaps just unclamp the one that got replaced, which we're suspecting of having the most shade, and move it temporarily into such a position that it gets full sun and perhaps is pointing more towards the sun (as long as that doesn't shade other panels, or at least not string 4, so you have something to compare it to). Hopefully you can do that without having to re-wire anything. Then see how string 1 compares with string 4 after that. Then at least you'll know if it's a shading issue, or something else (I can't think what else it might be off hand, but still).

Hi There

Me and my friend went up and lifted 2 panels in the PV1 string that has been giving me  such a little power.

It went to over 500 watt and beat all the other strings . So i definitely will have to lift the panels. Thanks for that.

 

Do you know of the cheapest place i can get this 30 degree brackets from to lift the panels .

 

Thanks Wayne

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54 minutes ago, WayneSi said:

Do you know of the cheapest place i can get this 30 degree brackets from to lift the panels .

I used Renusol framing for mine (when I still had my panels on a flat roof). Probably doesn't qualify as cheap but I found it fairly affordable. You can then also use the proper fixings for a corrugated roof, they have a really nice bracket that sits on the ridge of the profile, and (if I recall) they have a rubber underside to help seal it.

The way that I judge the cost of the frame evolved somewhat over the years. Back in 2013 there wasn't much choice. The local guys wanted to sell me a Schletter modular frame, which cost almost as much as the three panels I wanted to put up (which back then was R10/watt). So I welded my own, painted it and installed it. That worked well, except rust is an eventual problem.

So the second frame I made from aluminium angle that I bought at a local shop. The material cost twice what the steel was, but it took so much less time to make the frame (and no painting and waiting for it to dry!), so I swore I would never bother with a steel frame again.

When the next time rolled around (replacing the rusted steel frame), I found out that the Renusol is just a little more expensive than the material cost of my previous frame... I mean maybe 20% or so. And even faster to put together...

So now, I'd rather work a bit harder to pay of the credit card than sit in the sun on the roof building custom frames 🙂

 

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