Chloe Posted October 15, 2020 Share Posted October 15, 2020 It sounds like your "installer" used the wrong tipes of cable we would normally recommend 6mm solar cable and 70mm battery cable that's tipictly the size of your car's battery cable if you want to compare. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 You would have huge losses and a potential fire risk if those cables are incorrect. Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 13 minutes ago, Chloe said: It sounds like your "installer" used the wrong tipes of cable we would normally recommend 6mm solar cable and 70mm battery cable that's tipictly the size of your car's battery cable if you want to compare. If 6mm is equivalent to about 8 gauge car sound cable, then installer did in fact use that. Also the battery cable is about 4 gauge thick, while i think my car battery cable is about 0/1 gauge. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 15 minutes ago, profa said: If 6mm is equivalent to about 8 gauge car sound cable, then installer did in fact use that. Also the battery cable is about 4 gauge thick, while i think my car battery cable is about 0/1 gauge. Did a quick check online and it seem your solar cable should be ok but there's still the question about them feeling warm??? But your battery cable is incorrect for the batteries you are using it should be the same size as in your car. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 According to that calculation you should have at least a 2 gauge cable or 35mm on your batteries. Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 (edited) 17 minutes ago, Chloe said: Did a quick check online and it seem your solar cable should be ok but there's still the question about them feeling warm??? But your battery cable is incorrect for the batteries you are using it should be the same size as in your car. Could you share the calculations (voltage, amps, distance) you used to determine that the solar cable is OK? Edited October 15, 2020 by profa Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 1 minute ago, Vassen said: With a 3000w inverter at 24V, the max amps should be 125A. That translates to 35mm cable as far as I know. You can however use any size cable you want to as long as you have a fuse on the cable that is rated for the max current carrying capability of the cable. 35mm is battery cable correct? Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 1 minute ago, Vassen said: With a 3000w inverter at 24V, the max amps should be 125A. That translates to 35mm cable as far as I know. You can however use any size cable you want to as long as you have a fuse on the cable that is rated for the max current carrying capability of the cable. That's why I said it should be at least 35mm. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 5 minutes ago, profa said: Could you share the calculations (voltage, amps, distance) you used to determine that the solar cable is OK? I used a simple online calculater which converts gauge to mm to mm2. You don't have 20 panels so 4 mm2 solar cable should have been fine for your set-up. Unless you are refuring to this type of cable. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 20 minutes ago, Vassen said: Okay sorry. I thought for some reason you said 70mm cable. Guess I read wrong I said I prefer 70mm but he should at least have a 35mm. Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 8 minutes ago, Vassen said: Remember, he said he’s got 6 panels in parallel and each rated 8.7A at max power. So that’s 52A theoretical max. I can’t really find a proper site that specifies the max rating of dc cable. Different sites have different values. Chart in this thread is blurry but is what you want, no? Here Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 30 minutes ago, Chloe said: I used a simple online calculater which converts gauge to mm to mm2. You don't have 20 panels so 4 mm2 solar cable should have been fine for your set-up. Unless you are refuring to this type of cable. I think we are talking past each other here. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 Ok missed that one then 6mm would be under rated as well thats only 54amp. That leaves him with 10mm solar cable rated at 75amp. That means all his cabling is incorrect. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 8 minutes ago, profa said: I think we are talking past each other here. Yip sorry I missed the parallel so it seems all your cables are incorrect. profa 1 Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 3 minutes ago, Vassen said: yes. I've seen others like this as well. Even this shows that for 50A, at 15m, you would need 21mm2. so more or less the size of the current battery cable? Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 Just now, Chloe said: Yip sorry I missed the parallel so it seems all your cables are incorrect. worst part is, as i am having this conversation with the forum, im sharing all these facts with the installer, and am getting the "but these are the same cables we install on all our installations" story and basically no willingness to take responsibility for the massive oversight/screw up! Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 1 minute ago, profa said: worst part is, as i am having this conversation with the forum, im sharing all these facts with the installer, and am getting the "but these are the same cables we install on all our installations" story and basically no willingness to take responsibility for the massive oversight/screw up! Yes basically your solar cables should be the size of your current battery cable and the battery cable about 3 times that. As for the installer... always the case... I've even seen guys use 1mm housewire. Yellow Measure 1 Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 4 minutes ago, Vassen said: that seems excessive. I will try to find the sans regulations to see if anything is mentioned. The 6mm is definitely wrong as its getting warm which is an immediate sign that something is wrong. It's not 6mm solar cable. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 3 minutes ago, Vassen said: that's also a possibility. @profacan you maybe post a picture of the cable. All of the solar cables ive seen have some sort of description on them. He said it looks more like speaker cable but I da agree with a photo of the cables otherwise we're just speculating! Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 23 minutes ago, Chloe said: He said it looks more like speaker cable but I da agree with a photo of the cables otherwise we're just speculating! with all due respect, i never said that. i said its about as thick as 8 gauge car audio cable which is more than adequate for a 4 channel amplifer drawing 20-40 amps at 12v. speaker cable is between 10-14 gauge. Quote Link to comment Share on other sites More sharing options...
Chloe Posted October 15, 2020 Share Posted October 15, 2020 8 minutes ago, profa said: with all due respect, i never said that. i said its about as thick as 8 gauge car audio cable which is more than adequate for a 4 channel amplifer drawing 20-40 amps at 12v. speaker cable is between 10-14 gauge. Sorry not that clued up on car audio but its still not the right type of cable. I know some guys use battery cable. I've used some thick speaker cable as specially if you're running a few big speakers. Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 53 minutes ago, Vassen said: that's also a possibility. @profacan you maybe post a picture of the cable. All of the solar cables ive seen have some sort of description on them. pictures attached. battery cable is 25mm2 and solar panel cable definitely 6mm2 (picture i know isn't too clear, but i could make out its a 6) Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 1 hour ago, Vassen said: I would rather go with 2x 6mm2 cables. Probably cheaper, more common and easier to work with than 10mm2. actually was thinking the same thing. but i would really prefer a single cable as my OCD would bug the hell out of me with 4 cables where there should be only 2. Quote Link to comment Share on other sites More sharing options...
Bloubul7 Posted October 15, 2020 Share Posted October 15, 2020 58 minutes ago, profa said: actually was thinking the same thing. but i would really prefer a single cable as my OCD would bug the hell out of me with 4 cables where there should be only 2. 2x 6mm2 cables would allow you greater flexibility in the future. Believe me, the bug will get stuck and you will most likely upgrade your inverter in the near future. Quote Link to comment Share on other sites More sharing options...
profa Posted October 15, 2020 Author Share Posted October 15, 2020 19 minutes ago, Vassen said: I totally agree with this. You can also easily isolate part of the string if you need to. As I said, 6mm is more common, probably cheaper and easier to work with.... and you are getting 12mm2 instead of 10mm2 You also don’t waste the cable that you have. Use the cash towards the other missing elements in your system. according to this using 31v, 48amp, 15m length both ways (30m total) and 3% voltage drop, I need 50mm2? so even 12mm2 is hopelessly inadequate? Quote Link to comment Share on other sites More sharing options...
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