Newb with questions... Grounding & Charge controller amperage

[Mike90250]

....
..... these panels are rated at 5.95a Isc (35.7a total) and 5.49a Imp (~33a total). Am I ok with the C35 (35 amp) controller? .......

Will the charge controller handle 6 panels? Its a 35a charge controller... the panels should produce around 34a but that's at charge voltage. I have looked at quite a few manufacturers... some say it's within spec.. others say it's not. (midnight solar, morning star, etc... all had different answers when using their calculators). I know for a fact that the panels are not going to produce rated power with my installation... so can anyone give some input? Should I just hook it up and clamp test it to see what it is actually producing?

Thanks for the HELPFUL input.

You are at the borderline edge with 33A feeding into a 35A rated controller. I expect you to blow a couple 35A fuses, simply because they slowly fatigue and go bad when run close to their limit. The FET inside - if you keep the controller in a cool place, where it does not let the FET overheat, it should be OK..
It's not going to instantly burst into flame just from being so close to the limits.

[Mike90250]

So it would be wise to use 5 panels instead of 6 with that controller. I don't want to be on the edge.. I want to have some wiggle room. I'll plan to use 5 panels for the time being.

Good

Now If I wanted to have a slightly larger battery bank (12 215ah 6v batteries)... 2 controllers and 10 panels. That would be more then enough to supply all I'm asking out of it more then likely.

This is BAD (covered later) **

Also... yes please send me the information on sizing the bond wire for the ground rods, etc.

You pasted the answer in the image of the manual of the inverter -
a). Xantrex recommends the grounding conductor be the same size as the DC wires

And you cant use fine strand wire, supposed to be solid wire - in your case, copper rod !

** BAD design - 6 parallel batteries. Great if you have $$ to spend on replacing batteries much more often than needed . Current sharing in parallel banks is poor, one set takes most of the load, till it weakens, then the next best set, and so on as it cascades to an early death.
And then you have the fuses to install to protect the rest of the bank from the bad string when it fails.
Inverter: A 12V 2Kw inverter (180A) seldom has the heavy wire internally, required to maintain good performance, I feel better that you are using Xantrex - a name brand and much more likely to have built it correctly. Many imports use 8 ga wire internally to carry 200 A, or they use 1oz PCB instead of 5oz PCB and parts melt off the PCB as the inverter is running, They last because the voltage drop in the wire & batteries usually trips the low volt disconnect and it never fully heats up.

[Sunking]

And no... he deleted his original post because how he first said it made no sense. The 2nd time he posted it (after he deleted the original) did make sense.

Look back, I deleted all my post. I did so because you do not understand basic fundamentals. Installing Car Toys does not make you an electrician. You do not even know what article 250, 760, and 690 means. Three books you need to have memorized to do what you want safely and legally. You do not even know what UL 1741 means.

Take note no one here is answering your questions anymore. There is a good reason for that. We want no part of you getting hurt. You do not understand by using a 2000 watt Inverter in a home requires everthing in front of it is required to support it to the fullest extent. That means by code and all rules you have to use the 12 volt 1600 AH battery that weighs 1100 pounds, two very expensive 80 amp charge controllers, and 1500 to 2000 watts of panels to support the battery and Inverter. No Engineer, Electrician, FD, or Insurance Investigator gives a damn what you intend to use it for. It is the fact of what it is capable of doing. Non eof those professionals who license and reputation is going to give you a nod or make you feel good. Only salesman, DIY, and those vested will tell you what you want to hear.

FWIW the Forum can and will be held responsible for its content good or bad. The mods and owners are not going to allow you to receive bad advice.At least not without WARNING. Go to Northern AZ Wind and Sun Forum and get all the dangerous advice you seek. Just Google it. They do not give a damn about you over there. They have not been sued yet.

[Sunking]

Something I don't understand about what the xantrex manual states. It recommends 0awg for the dc wiring... then specs 6awg for the case ground... (then shows that it suggests using the same wire size for the case ground as the DC cables. Why not just spec the right size ground from the get go instead of making it a side note?

OK I will answer that question. Because it exceds minimum requirements, and assumes longer cable runs in a mobile application which result in high voltage losses. Exact same reason you overkilled 12 volt Car Toy stereos. You just never knew why. Codes are minimum safety requirements. No problem exceeding them, you just have to meet the minimum.

With low voltages like 12, 24, and 48 volts minimums have to be met. Example a 6 AWG Marine Grade 105 degree conductor with super flex tinned conductors is good to 105 amps in free air. However if longer than 5-feet 1-way the voltage loss exceeds 3%. So if longer than 5 feet 1-way you would upgrade to 4 AWG that gets you out to 15 feet. In a home you should not need to go more than 5-feet 1-way. No tso in mobile applcations.

So here is my last piece of advice to you and all DIY's. The largest Charge Controller you can buy is 80 to 100 amps. At 12 volt limits input to 1000 watts, 24 @ 2000 watts, and 48 volts @ 4000 watts. All can be donne with 6 AWG wire which just happens to be the largest wire a DIY can handle with Garage tools and single-hole connectors. Larger than that requires special hydraulic tooling using 2-hole compression connectors, proper use of anti-oxidant, and frequent Torque Wrench inspections. Lastly no one cares if you burn your Truck or RV up from foolishness and ignorance. You cross a line when you put things in your home and the rules get real strict.

So Xantrex covered their arses with over kill and unnecessary expense. If you used 4/0 AWG, and a fire happened, they can prove beyond any reasonable with any expert was your fault. No question about it, you improperly terminated the cable or let it get loose. All that heavy cable on a single hole or mechanical connector worked it way loose and you failed to exercise proper workmanship and maintenance. A licensed pro that was hired or city Inspector has no place to hide and is liable. DIY and you have no defense.

Good luck.

[Sunking]

You say 100amp charge controller is the largest you can buy so 1kw is the largest system you can go with (12v system)... why not multiple controllers? Never heard from anyone that multiple controllers would be an issue either...

Yes some may require multiple controllers. Example, lets say we have 2000 watt panel array with 12 volt battery. That would take two very expensive 80 amp charge controllers at $600 for each unit or $1200 worth of controllers. That would most likely be a very foolish mistake. Why you ask? Real simple the operator made a huge stuck inside a 12 box mistake. They did not know if they had selected 24 volt battery would only require one controller and much smaller wire between battery and load. If they were really experienced would use 48 volt battery and a single bring cost way down. Not to mention 24 and 48 volts systems are exponentially more efficient than 12 volts. Today you can go up to 120 volt battery and with say a 100 amp controller means panel wattage of 12,000 watts. So unless you need more than 12,000 watts, there is no justification using two or more charge controllers. No one on this forum would tell you two charge controllers is OK. You would have to have some very niche application to justify doing that like an RV. which cannot hold 1000 watts of panels.

The only place I have ever heard of limits placed on what you could power at certain voltage levels... which is why I've been somewhat blunt about it. When you read and hear from 100 different sources that this way is OK... but you have one source tell you it's not... you become skeptical of that one source... do you not?

Those so called 100 people you are referring to not likely professionals with 40 years experience. My bet is on You Tube or DIY sites. In other words they do not have a clue.

Look I am a PE (professional engineer) with just about 40 years experience and have deigned/built hundreds of commercial off grid battery systems. I come from the Electrical Power Generations and Telecom sector. I have worked with every major battery manufacture in the world, contributing author to IEEE Pb battery standards written dozens of while papers for professional media and trade magazines, and sat on NEC code panel 9 for 6 years which organization is who writes NEC code requirements.

From my POV I am a medical doctor and you are my patient. As my patient you are trying to tell me smoking is not bad for or dangerous because 100 people told you so. The only way I would approve of you smoking is when you are lying in your death bed and want to smoke. To late to quit now. Smokem if you gotem until you cough up your lungs with you last breath of air. All I could do is to offer to light your cigarette, or give you a gun with one bullet that has your name written on it. As a PE, like a doctor, I am sworn to do no harm or put your life in danger. As a PE I am liable for my work and recommendations just like a doctor.

[Sunking]

See.. this is what I mean. I ask for your input on a proper system... suggestion on a quality inverter... controller... etc... and this is the bs you come back with..

You asked why no more than 1 Controller. I answered you. Then you asked why 100 wannabes say the opposite of what I and others here repeat or concur. I answered you.

Now you rant because I did not answer what are good Inverters and controllers to use. That has been answered many time already along with a comprehensive list of all the manufactures that make Inverters approved for premises wiring. Take your pick

Like I said you do not understand what you are being told, and if you did, forgot it the next moment.

[Mike90250]

Wires
many find strands of wire rot and corrode away quickly, which is why solid or coarse braid is required for grounding applications,

Inverter
Somewhere, I missed what your load is, a fridge, lights, cell phone chargers ?? A fridge, with any sine wave inverter, is going to need at least 1100watt inverter to reliably start the compressor motor. After that motor has started it's running on less than 200w, but that big inverter still sucks a lot of power just to keep it all warmed up !
Victron makes some nice ones, https://www.victronenergy.com/inverters
and also Samlex, Xantrex, Exceltech
Varrying price points, sizes, surge capability,

[SunEagle]

Also.. I have a DIY idea in mind for a fused combiner box.

For safety's sake, I want to fuse each panel. I'm thinking about building a combiner box using a small sealed enclosure and something like this...

https://www.amazon.com/OLS-10-Way-Blade-Indicator-Protection/dp/B00QMTAZ1W/ref=sr_1_1?s=automotive&ie=UTF8&qid=1485538206&sr=1-1&th=1

A universal automotive fuse block. The block itself is rated for 100a total. Each circuit is rated for 30a. I want to use it backwards... positive output of each panel to a fuse "output" on the block. 7amp fuse (or less) then the main output would be the "input stud" on the block. 6awg running from the stud to the controller with a large fuse between the block and controller.

In total, it would make a nice little sealed/fused combiner for under $20

Would you see an issue doing something like that?

Be careful using automotive DC components. They may not have the voltage rating that they would see from the PV panels. Especially if you series wire them.

I built a combiner box using fused switches. The box came from Home Depot but the fused switches, terminal blocks and fuses were purchased either through Amazon or eBay. I do not remember what I spend altogether but it was not cheap. It dose work for me and can handle up to 5 panels.

Attached is a picture of that box.

[SunEagle]

This would be just for the small 12v setup (fuse block in question is rated to 32v) . I'd have to go a different route come time to go 24v+. I've got one of these little blocks laying around at the moment.. but I'll price out building one to handle my future plans from the get-go. If it is cost effective, I'll go on and build it that way to keep from having to do the work twice.

Thanks

The 32vdc rating should work if you wire your panels all in parallel and their Voc < 32v.

I just thought I would bring it up because I have seen other people try to use similar auto fuse blocks only to hit them with about 55vdc (3 x Vmp = 18.5v battery panels wired in series). The block did not like that higher voltage.

[littleharbor]

You sound like a DIY kind of guy. Building your own Combiner box is a fun and satisfying project. Use PV rated fuses and appropriate fuse holders. DIY combiner box.jpg

[SunEagle]

I see that bussman offers class h fuse holders rated at 125vdc/250ac. Found a bunch of them on ebay.. 3 gang for ~$7 each. NON - 10 amp class H fuses (rated at 250v) for cheap as well. Would that do the trick? Wouldn't be as clean as the single block with single lug... but should still fit the bill if I'm thinking correctly.

Haven't look into anything PV specific yet but will.

If you look close at my box you will I have 2 x 2 pole AB switches and a single pole made by Shawmut. They are all rated 600V 30A and accept type CC fuses. I think I have 8 amp fuses for each of my panels. Those bussman should work. Just don't open the fuses while the panels are producing. The fuse holders do not have a way of eliminating any arc.

[SunEagle]

You sound like a DIY kind of guy. Building your own Combiner box is a fun and satisfying project. Use PV rated fuses and appropriate fuse holders. DIY combiner box.jpg

You would be surprise of how much stuff I have DIY over the years. My two small solar/battery systems are just the tip of the ice-burg.

I could tell you about a home I helped rewire and some of the 480volt control panels I built for an industrial plant. All done per code and using the best parts money can buy.

[littleharbor]

The one I built used these fuses which go in touch safe fuse holders. I also incorporated MC-4 connectors into it so connecting panel strings is super easy without having to open the combiner box. The unused MC-4 connectors are capped with blank connectors. You can use a typical buss bar for the neutral connections. . These are generic pictures just as examples. My setup is in Baja and I don't have any pictures of it. It is also a bit larger. Ground buss bar.jpgPV fuse.jpgTouch safe fuse holders.jpgCombiner box.jpg

[SunEagle]

I assume covering the panels prior to removing/installing the fuses would do the trick?

Either that or when it is dark out.

Figure those fuses are only needed access when they blow. So it is De-energized when you open the circuit.

Of course if you blow one and it has two others on the mechanism you end up needed to wait until the sun is not there or you could get shocked or the holders could fail.

[Sunking]

Like I said, no longer need your input. Thanks anyways.

You do not have that choice.

As for fuses between panels and Controller are NOT REQUIRED or NEEDED provided you keep the panels strings to 2 or less. No one has told you that either. I just saved you money. But don't listen to me.

There are also a lot better battery fuse options. You want the fuses bolted to the battery Term Post. One facing the controller, and another inverter to save your dumb ass. They did not teach you that at Car Toys did they? No one else told you that either and less expensive than your dangerous ways. Again just saved you a lot more money and a fire.