Help!

Re: Help!

Basically the same product, your 5V looks to not have as a robust leak proof seam as standing seam would

http://www.gulfcoastsupply.com/product_5v.htm

vs.

http://www.gulfcoastsupply.com/product_seam-dbl-lock-panel.html


Regardless, let the professionals handle this, make sure your selected installer knows the construction and be prepared to have to have your roofer come back ... your doing this all backwards .. I.E. you should have had the racking and mounts designed, approved and permitted before you had the new roof installed.

One other thought, if you have the land, its easier on the cost and permits to have ground mounting .. if it turns into to much costs or concerns mounting to the roof, ground mount is all around a better choice, better performance, easy to clean and maintain and doesn't require PE approved mounts which means lower costs

Re: Xantrex XW GT Connection

Time for Solar Source to learn the XW stuff ... Since your looking at a pair of XW-6048's I assume your going to just have charge controllers for the Solar to battery regulation and the XW's for GT and backup. Its a very clean install when you use the Xantrex accessories and probably 10-15K lower cost.

You can buy all the stuff from sunelec in miami on the XW's , pretty sure all the solar related stuff is tax exempt

I would never use the SMA stuff, ridiculously over priced and doesn't even do split-phase in a single SI. I think there are 4-5 of us on the forum from Florida that have XW-6048's ... a great and flexible inverter/charger

Re: Xantrex XW GT Connection

CaptTurbo wrote: »

Thank you for your thoughts. That is how I hope to go but Solar Source really isn't comfortable with doing either battery based grid tie system. I'm a little surprised since they make a big point of having been in this business for 26 years.

Well GT has only been around for a few years, I was the first permitted system in central Florida in 2003, SS has been in business what they advertise but in Florida, its few and far between for generic GT installations and for what your thinking about I doubt there is more than a couple ( if any ) system installed in Florida that does AC coupling ( Sunny Island )

Solar Source is 100% doing the right thing in saying they will have to hire an engineer to design and they will install a custom system that is pretty complex, thats probably the first honest and correct answer you have gotten from a company since you started your project.

Battery systems are a huge pain as it requires custom or expensive racking for the battery's, lots of custom high amperage wiring , breakers, enclosures, dealing with charge controllers and 4-6X more wiring on the Array side, likely the building department won't have a clue which means lots of extra hours for your installer teaching the building department whats right and wrong.

If your looking at dual XW-6048's you'll need at least a 1000ah battery bank and it also going to get messy with you current service panels as loads will have to be moved from the service panel to a new sub panel at output of the XW's

I can offer suggestions;

1) Define on paper what you want exactly, what is a want vs a need as well.
2) Listen to the professionals and they can properly build to what you want
3) Open your wallet, this will be a very expensive installation .. in general terms a turnkey job is 2X the parts costs, and you haven't bought all the parts yet

At some point to go any further, you will have to invest significant funds to continue. No Installer will start do a plan with out being paid for the system design work.

If you do go with Solar Source, you can tell Wayne the owner he can contact me if he has questions specific to the Xantrex products, they are best available, Wayne uses SMA because his distributor stocks them and with the volumes so low in Florida it makes no business sense to use more than one manufacture for PV, unless someone like you comes along and needs a very specialized system


In other trades, refrigeration as an example, the manufactures require you have a license to purchase there products, its to prevent unqualified people from damaging the equipment or themselves.

A person with basic electric skill could probably wire GridTie and get it working, battery based systems have the real potentional of being leathal, no BS ... a 48V battery bank with unlimited short circuit current is probably the most deadly thing I have ever worked on.

I have no connection with Solar Source except of having professional met the owner a few times, everything I have heard when I meet people in the business is nothing but complements on the business he runs.

I hope this gives you some honest guidance on how to proceed and if anyone makes it sound easy, don't believe a single word they say, they will be just like the place you bought the parts from, all they want is your money.

Re: Help!

A couple of thoughts on your battery size;

Your T105's are golf cart battery's, ~200ah , which means they would under ideal condition provided 5ah for 20hours ... that ~475 watt-hour load. You really shouldn't use the battery much below 50% if regularly discharged and 80% ever or you will quickly kill the battery's

You mentioned you want to be able to run the AC if the power is out, a 4.5 ton unit thats a typical Seer 10 will pull about 5kw steady state and probably more than 12kw on the start-up surge. So your asking a battery pack thats rated for 5ah per hour to supply 250 amps on start-up surge.

Batterys have whats called internal resistance, as you increase the amp draw the voltage drops and this drop is INTERNAL to the battery's, meaning the voltage drop times the current is turned into heat, not energy that can provided energy to the load. If you load these little battery's with start-up surges or even steady state loads, they will last less than 1 hour and even if you manage to get the AC started when fully charged, 10-15 minutes later they couldn't even do that as when the AC kicks in the inverter will shutdown with a under voltage fault. I know this as I have first hand tried to start and run my 4 ton AC with the same amount of battery's you have.

Even if you AC Couple, the XW has to burden the majority of the load to maintain UL1741 quailty frequency and voltage otherwise the GT inverters will trip ( 3 bad 60hz cycles or about 50ms ) and shutdown. There is no way around having a large battery bank to run multi kilowatt inductive loads

One last suggestion, the battery place in Lakeland has racks and racks of used or date code expired battery's ( I'm sure you can find one near you, look in the yellow pages ) They might only have 20-50% of new capacity, but its dirt cheap. When I bought my AGM's, they had 12V 100ah, 2 year old never used AGMs for 25 bucks each. I didn't get them and wish I had, but there is always something laying around they will sell cheap, forklift battery's are another source of low cost. Maybe not a good choice of daily cycling, but great for the once a year outage. For a few hundred you should be able to have a 1000ah 48V pack going this route

Oh and stick to AGM if you can, wetcells, especially if they just float all the time will use lots of water and you need to check them weekly for the levels in the battery's. Number one failure of wetcell in this configuration is people don't check the water level and the plates get exposed, short out and die.

Hope some of this helps!

Re: Help!

Solar Guppy wrote: »

I helped out submarathon3 when he did his system last year in Bartow

My rule is if you help someone, then next time, its there turn to help the next fellow

Good luck!

Wow, I don't know how I missed this thread for two weeks. But Solar Guppy is 100% correct, without his help, the equipment would probably still be sitting in the garage. He is EXTREMELY knowledgeable and I am extremely fortunate that I live within running distance of him and he would spend the time showing me around his setup. So hopefully I can help out here.

It is somewhat the same situation I had with the installer/electrician, who was supposed to be a good friend and also an expert on solar. He was able to sell me the equipment, but after that he was hard to find. I stayed up until 3 a.m. many nights figuring out about this.

I too have the XW6048 with battery backup. I figured out the system and I figured out the wiring layout and I pulled the permit myself. Once again, this was supposed to help since the "installer/electrician" wouldn't have to do it.

Now, many times they say "Go against Solar Guppy's advice at your own peril." I tried to keep that motto in mind as I proceeded. I did choose a Rolls-Surrette battery over his suggested AGM battery. I got the batteries at a good price though from DC Batteries in Miami. Part of the reasoning was as it combined with the Federal 30% solar rebates, it was much better buying an expensive 15-year battery as opposed to an AGM 7-year battery.

I would also strongly suggest contacting Cauley Electric here in Bartow. You can visit their website at: http://www.cauleyelectrical.net/ They go all over the state of Florida, and even into Georgia and Alabama I think. The owner, Mr. Cauley, and Brett and the crew know about PV and Xantrex inverters. They also listened to what I wanted and did it. When I said I wanted to oversize the wiring by several sizes, they didn't make any remarks like "we've never done that before, that's ridiculous," instead they said they would be happy to do it and it would definitely reduce losses. Also, the price they charged for the work was definitely fair, and they will stand behind what they install.

Now the roofing, that was a fiasco. The roofer who put the roof on the house had me contact one of his roofers as a side job. This guy was supposed to have done several installs, and he was a real nice guy talking to him. However, when he started putting the brackets up on the roof, I wondered why he hadn't snapped a chalk line. He said he knew what he was doing. Well, the first dozen were pretty straight, and then they started to vary slightly. By the time he was on the 80th one, the rows looked like a sidewinder snake in Arizona. So I had to get up on the roof and loosen the misaligned ones and get them in line as best I could. It turned out to be a pretty fair job considering what I started out with. I also found out that the rails can take a bit of flex, they don't have to be perfect like I would have had them if I had done it myself.

He was supposed to come back and put the panels up on the rails, since he had only been paid to put the brackets in up until that point. I waited and waited and waited and then he didn't show up. I guess the rest of the money wasn't worth the time he would have to spend finishing the job. So finally, after waiting a month I was desperate. Remember, simultaneously I was having a major problem getting the installer/electrician to come out too. So one day I got the ladder, leaned it up against the house, and lifted the 21 panels up to the roof myself. I think if they had even weighed a pound more or been an inch bigger I wouldn't have been able to do it. It was a real challenge with the wind too, even with just a slight breeze it would catch the panel as I was going backward up the ladder holding the panel. But now they are up there perfectly aligned because I spent the extra time doing it.

Now the installer/electrician was another story. First, to fill out the rebate you need his license number. I figured I would save everybody some time, just go on the computer and get it. Well, that was interesting. It said "Inactive." OOOH, that can't be good. So I called him about it and he said, "Wow, I didn't think I had to renew it for another year or so." OK, so then everything has to stop, because for Florida it must be a certified electrician installing it, and now technically he wasn't and I couldn't risk being denied the rebate because of him. Now, he didn't seem too worried about it, and within a month he had taken care of that. So finally he could come out and start installing the conduit, a basic task for an electrician. So he gets here, looks at the conduit I had bought, and starts trying to figure out what angles to bend it so it could be installed. Then he says the ominous statement, "Wow, I haven't done this in awhile." Then he says he didn't bring the right tool and we'd have to figure out another time. In the mean time, the guys down at the electrical supply store where I'm buying all the conduit and wiring are telling me, "Fire the electrician." So finally I didn't know what to do. Once again Solar Guppy came through with great advice, saying "Just move forward every day and don't worry about everything. If you do it wrong, it isn't a disaster, just go back and do it again." So that gave me the bit of courage I needed, and started doing it myself. And I did a relatively good job for a non-certified electrician with installing the conduit. However, another BIG mistake. The NEC book said the conduit could serve as the Equipment Grounding Conductor. Solar Guppy said that probably wouldn't work, and I better talk to the local head inspector. He also said that there must be an EGC, just conduit wouldn't be acceptable. That was a major disaster because I had done all the calculations and didn't have enough room in the conduit for another wire and still be within the NEC rules. At that point, I figured I better get somebody who can help figure this out, or I'd be working on it for another 6 months.

The guys at Cauley Electric came out, looked at it, and jumped right on it. The crew wired the solar panels up on the roof, figured out about getting the wiring into the attic, which I couldn't, and did very professional work with all the wiring and running another set of conduit. So since there were now two sets of conduit, I could really upsize the wiring, which they were able to pull through without any problems, another task I figured that I couldn't do myself.

So yes, after all of this I ended up with the great system. But I had to get through a bit of ridiculousness with some of the people I dealt with. But really, I have been so thankful that so many people on this forum have been very helpful.

Re: Help!

The biggest issue is startup of the compressor, almost 100% of the surge has to be handled by the XW-6048, if it sags, the GT's drop off line within 50ms and its all on that wimpy little battery pack to push out 12kw+

Re: Help!

If your only connecting 2.5kw thru a single charge controller, your 200ah battery should be OK, that about the limit for 200ah bank

I assume the other 7.5k will be pure GT

It was the talk about going 100% to the battery's then GT from dual XW-6048's that would require more Ah, but that also could be handled with cost effective used battery's

Re: Help!

CaptTurbo wrote: »

Actually it's a bit confusing for me SG. Hard to describe in this back and forth but I'm trying. Solartron sold me a system with a SunnyBoy5000 GT inverter, a PVP2500 GT inverter, XW60-150 CC, and the XW-6048.

Of the 44 230 watt panels, 12 were to be sent through the CC to the battery bank / XW-6048. The rest were to be sent to the GT inverters.

It seems like a very overly complicated system to me too. Because the XW6048 will accomplish everything you are trying to do without having any GT inverter. Solar Guppy is very enthusiastic about the XW inverter, and now that I have one too I can also say it works great. Also, what do those two other GT inverters add up to? It is probably much more than another XW6048.

I too wanted to have backup power, so I went with the battery system. In my opinion, it didn't add that much complexity to things. The one problem was that the wire had to be so big because of 48V instead of 480V with a GT system. Some say that you lose 50% of the PV output when you've got batteries, but I don't find that to be true at all. The power output of the PV is at about 83% of the system rating, at least from what I can tell. Also, I don't know about a big expense for the battery enclosure. I went to Lowe's, got several 2x8s and built the enclosure. It even turned into a table instead of wasted space.

So if it going to be a 10kw system, you should be able to return the unused GT inverters to the place you bought them from. Yes, there is a shipping cost, but in the long run that is just a bit of an added expense to gain a bit of knowledge. In my opinion, I would make a complaint about their sales tactics just for suggesting an XW6048 for 2.5kw of PV. It is like driving a Ferrari three blocks to work in bumper to bumper traffic. Why do it?

Also, I was able to get the permit myself here in Polk County. I did all the research, got advice from Solar Guppy on some of the more complicated issues, had a little drawing showing everything in detail, including the wire guage between each connection. I did it that way because the first time I went to get the permit they said they wanted a "detailed" explanation and sent me away. So they got what I think is the most detailed version I could come up with for my second trip in. But then they stopped me again because even though the roof mounting system was certified by the manufacturer, Conergy, it wasn't certified here in Florida. So luckily Solar Guppy sent me to the great PE, Robert Haug, and he got it figured out and certified. I still think Conergy should have reimbursed me for that expense though, I wonder if they are using the certification I paid for on other systems they are selling here in Florida. So as far as the permit goes, yes it cost me a bit of time, but to pay somebody else to do it would have been expensive and I wouldn't have learned what I did.

One other thing that I found out after having the system for awhile is that a very large percentage, maybe even more than 80%, is used here instead of feeding back to the electric company. And if I really tried, I could probably set things up to have none feeding back, but of course this is with a 5kw system. So you might be able to set up one subpanel that would use 100% of the output of one XW6048, a "mini-off-grid," and backfeed the main panel with the other XW6048. For running an AC unit, it is possible to get what they call a "hard start" but I call a "gentle start" which would reduce the few seconds of high demand at the startup.