Using two different brands of 10AWG cables from solar panels to EcoFlow Delta Pro

[tspmdt]

I am relatively new to the solar world and thus the beginner category.

In late November I purchased a kit with two EcoFlow Delta Pro's, 8 Rich 335W panels, Double Voltage Hub and all the associated accessories, including two sets of 50' cables. Given the 150V and 15A limitations of the Delta Pros I plan to configure the panels with two sets of two in series which feed a parallel adapter for each Delta Pro. Since purchasing I have performed a fair amount of testing and am close mounting the panels. There will be two mount locations. One about 100' from the house and the second about 85' from the house.

Most calculators indicate that I should use 8AWG cable, but I tested by combining the included two 50' sets of 10AWG cables for a100' run and the voltage drop was less than 1% (77.4V vs 78V). Therefore I don't see a reason to upgrade to 8 AWG cable. I will use both sets included with the kit for one run to the house and am looking to buy a second a set cables for the second run.

The included cables are 50' of Slocable H1Z2Z2-K 1x6.0mm2. This is tinned copper.

Given that many components of the kit were made in China, I would like to purchase the cable for the second run from a USA manufacturer. A small concession I know. After some searching I discovered that TEMCO has a similar product for a very good price, relatively speaking.

TEMCo 10 AWG Solar Panel Wire

There are of course some differences:

• The Slocable wire is tinned copper where the TEMCo is bare copper.
• I believe the Slocable wire had more strands, but I can't confirm how many. TEMCo appears to have 19 strands.
• Slocable rated at 1000V and manufacturer says 70A but vendor says 40A. TEMCo is rated at 600V and 40A.
• There are differences in insulation as well, but I plan to run in conduit
• Other differences on which I'm getting up to speed

So here are my questions.

• Given the distance and the differences listed above is there any reason to believe that the TEMCo wire will perform significantly different than the Slocable?
• Does tinned copper make a significant difference?
• Any other factors to consider?

Appreciate any feedback.

Thank you!

 

[Bobert]

Any other factors to consider?

The voltage drop depends upon the amperage load on the wire. Did you check your voltage loss under a full load in full sun?

 

[tspmdt]

Thanks for the prompt response and subsequent query "Bobert".

During my testing I captured the input watts via 2Series+2Parallel to the Delta Pro with 0', 50' and 100' extensions, but I discovered that by setting the "AC Charge Speed Switch" to slow or variable, it was also limiting the solar input. According to the manual this switch is used for AC charging, but obviously applies solar as well. So I need to retest at variable lengths without limits.

I was testing under full sun but did not check the voltage under full load. Looks like that is the next test I must run. I think I know what I have planned for mid-day tomorrow. The learning continues....

I'll check back in with results.

 

[Bobert]

Thanks for the prompt response and subsequent query "Bobert".

During my testing I captured the input watts via 2Series+2Parallel to the Delta Pro with 0', 50' and 100' extensions, but I discovered that by setting the "AC Charge Speed Switch" to slow or variable, it was also limiting the solar input. According to the manual this switch is used for AC charging, but obviously applies solar as well. So I need to retest at variable lengths without limits.

I was testing under full sun but did not check the voltage under full load. Looks like that is the next test I must run. I think I know what I have planned for mid-day tomorrow. The learning continues....

I'll check back in with results.

Wire size for solar is usually best determined mathematically. The most important thing is to make sure that you don’t have the potential to overheat your wire under full load. The second factor is how much efficiency you will loose through the wire. For the purpose of safety you want to make sure you don’t pull over 30 amps on a 10 gauge wire. In my application I have more solar than I can use when the panels are in peak production so I was not concerned about efficiency loss. I use my camper in partial shade and cloudy conditions with great frequency and my panels are mounted flat on the roof of my camper. My system is designed for comfortable production at 1/4 of my potential output. At 1/4 output the 10 gauge wire has essentially no loss of efficiency but at full output I will lose somewhere between 2 and 5 percent of my output. I have a relatively short run of wire as the wire gets longer the efficiency loss gets exponentially worse. If panel output efficiency is important in your situation you will want to follow the math. If not be sure you are within “safe” numbers and you are good as long as you have good connections for all your wiring

 

[Browneye]

WAY Long runs - trees in the way?
Tinned wire is just more corrosion resistant - same conductivity. Generally considered marine grade, in many cases has heavier or more durable insulation.

Unless I mis-read, from your panels specified, each delta unit will get 4x335w solar panels, 2s2p - the potential to produce about 11A at 96V give or take. 5.6a each @ 49V, times two in series, times two parallel.

Here's a wire ampacity chart for recommended gauge. A 100' distance is a 200' circuit - 6awg is recommended in the 'non-critical' column. Remember, DC wire runs are round trip. A 150v rated SCC may be suggested. You'll get quite a bit of voltage drop, which is not so critical for PV current - just size accordingly. You MIGHT get by with 8 gauge if your panels don't reach their solar capacity.

Seems like an expensive array and a lot for just wire, for charging a couple of expensive solar battery units. [shrug]
If they're just for backup, and you have grid power, might be better to just plug them in, depending on length of power outages. Or be able to deploy a portable array much closer for a grid-down situation.

 

[tspmdt]

Wire size for solar is usually best determined mathematically. The most important thing is to make sure that you don’t have the potential to overheat your wire under full load. The second factor is how much efficiency you will loose through the wire. For the purpose of safety you want to make sure you don’t pull over 30 amps on a 10 gauge wire. In my application I have more solar than I can use when the panels are in peak production so I was not concerned about efficiency loss. I use my camper in partial shade and cloudy conditions with great frequency and my panels are mounted flat on the roof of my camper. My system is designed for comfortable production at 1/4 of my potential output. At 1/4 output the 10 gauge wire has essentially no loss of efficiency but at full output I will lose somewhere between 2 and 5 percent of my output. I have a relatively short run of wire as the wire gets longer the efficiency loss gets exponentially worse. If panel output efficiency is important in your situation you will want to follow the math. If not be sure you are within “safe” numbers and you are good as long as you have good connections for all your wiring

Thanks for these comments and guidance Bobert. This thread alone has been extremely helpful. It is so beneficial to have knowledgeable and experienced people reviewing other's problems.

As for overheating the wire, I don't think it is possible with the existing 10 gauge wire as the Delta Pros have a 15A limit on the solar input port. Assuming the voltage is close to 80V, then I should max out about 1200W during peak periods.

As for sizing of the wire gauge, I am okay with some loss as my panels will produce more power than the Delta Pros can take. Today I measured two panels in series with 100' of extension cable and also with no extension. This was early afternoon about an hour or hour and a half past peak sun and a fairly clear day. The Delta Pros input indicated 500W with 100' extension and 520W with no extension. So I don't know how easy it is to calculate voltage drop, but power drop is about 3.5%.

Here are the specs for the panels I have.

WAY Long runs - trees in the way?
Tinned wire is just more corrosion resistant - same conductivity. Generally considered marine grade, in many cases has heavier or more durable insulation.

Unless I mis-read, from your panels specified, each delta unit will get 4x335w solar panels, 2s2p - the potential to produce about 11A at 96V give or take. 5.6a each @ 49V, times two in series, times two parallel.

Here's a wire ampacity chart for recommended gauge. A 100' distance is a 200' circuit - 6awg is recommended in the 'non-critical' column. Remember, DC wire runs are round trip. A 150v rated SCC may be suggested. You'll get quite a bit of voltage drop, which is not so critical for PV current - just size accordingly. You MIGHT get by with 8 gauge if your panels don't reach their solar capacity.

Seems like an expensive array and a lot for just wire, for charging a couple of expensive solar battery units. [shrug]
If they're just for backup, and you have grid power, might be better to just plug them in, depending on length of power outages. Or be able to deploy a portable array much closer for a grid-down situation.

Thanks Browneye.

So I am learning from you as well. I wasn't aware that the distance is round trip. So that it very helpful. And I thought I read the tinned wire provide enhanced conductivity (apparently not), but it makes sense to be more corrosion resistant.

The reason for the length is that it is the best location in proximity to our utility hookup. Yes trees are a factor, as is the house. I am attempting to position them so that they get almost all of the morning sun and a majority of the afternoon sun (currently up to 4pm).

Thanks for the table. This certainly helps with sizing.

Given the panel specs above as noted to Bobert, I believe I should be able generate close to 1200W for each set of 4 panels in 2S2P. So do the numbers I produced today give me some indication of voltage drop? I've been getting a bit lost in the calculations. If the wattage provided to the Delta Pros only fell 3.5% (520-500)/520 by testing two panels in series, should I expect that I can generate close to 1200W in 2S2P? (This test did not position the panels in a peak direction). The other day I had one test with 100' extension that had generated 1100W.

As for being an expensive array, I agree. The purchase is multi-purpose though. The two Delta Pros feed a transfer switch to power 8 key circuits in our home (i.e. the typical items: well pump, refrigerators, freezers, technology, etc). Eventually I want to run these circuits solely from the batteries while being charged daily, assuming sun. I am testing as I type. I can run about 12-14 hours currently. This will help with the electric bill and reduce my dependence on utilities. It will also provide continuous power to those items during an outage (and we have them several times a year in this area). And God forbid if all craziness breaks loose, I will have some power without the need for gasoline. One additional benefit is they are portable and I can use them to power equipment away from the house when needed.

Currently I am considering purchasing 8AWG for the 100ft run and using the existing 100ft extension of 10AWG for the 85' run. The 85' would be Slocable and the 100' would be TEMCo.

Appreciate any feedback on these topics.

Apologies if I am misusing or abusing terminology.

Thanks!

 

[Bud Martin]

I am interested in the Slocable.
Are you buying directly from them, price for the 85ft? I do not see how to purchase directly from them.
Thanks.
BTW, all my Solar cables and extensions are from TEMCO (found them through Will's video), and they are in my local Bay area.

 

[tspmdt]

I am interested in the Slocable.
Are you buying directly from them, price for the 85ft? I do not see how to purchase directly from them.
Thanks.
BTW, all my Solar cables and extensions are from TEMCO (found them through Will's video), and they are in my local Bay area.

Hi Bud,

I purchased my kit from shopsolarkits.com. The kit came with Slocable, so I assume the individual cables they sell are Slocable. It doesn't indicate on their web site who the manufacturer is. They don't have an 85' cable, just 70' and 100'. I plan to trim my existing cables to 85' and add connectors.

Just curious, why are you considering Slocable? The TEMCo's are made in the USA and the price difference is minimal. Just need to add MC4 connectors.

Thanks

 

[Bud Martin]

I am just looking for PV wire with fine strands tinned copper wires instead of 19-strand pure copper wires. I can buy then from Bulkwire.com but they only come in Black only, I also want to use them for other projects as well.

https://bulkwire.com/solar-pv-wire-600v-ul-4703

BTW, I just found out that Slocable also sell their products on Amazon.