Re: [RE-wrenches] Three-phase off-grid
Ray, The nice thing about the Exeltech (and what made me decide to use them) is that they are not large. They are simply an array of 1 kw inverters, allowing for multiple redundancy. Essentially, a 30 kw three phase inverter is 31 small inverters, which, with the removal of two nuts, can be swapped out in case of failure with the system running and replaced. I, too, liked the idea of a separate charging system and we will be splitting the system into 20 kw of PV charging to each of three battery banks, one for each phase. Daryl HI Allan; I haven't tried the large Exeltech inverters, but I could see some advantages to having a separate charging system, and keeping the inverters supplying stable power. Everytime a generator coughs or switches from one source to another, it seems to cause trouble. The generator could be sized smaller, since it wouldn't need any surge capability. It would always run the same charger, and the inverters would always run the same loads. I'd at least take another look at it for my next large project, but cost might be a limiting factor. Here's a Cummins diesel DC generator, just to think about: http://www.cumminspowerproducts.com/DCgensets/Other/1500.pdf Ray On 10/21/2011 4:56 PM, Gary Willett wrote: Alan: Thanks for setting me straight about 3-phasing the Outback Radian - I was not aware they are limited to parallel single phase applications. Regards, Gary Willett On 10/21/2011 15:29, Allan Sindelar wrote: Gary, I was surprised by this information, as I had presumed that both units were for single-phase only. So I checked. Mary Raub in tech support at Outback told me that the Radian works only in 120/240 single-phase, although they are stackable in parallel. Someone in Schneider tech support told me that the XW can be used in three-phase, up to six units (36 kW). Setup instructions are in Appendix D of the XW installation guide, found online at http://www.global-download.schneider-electric.com/85257849002EB8CB/all/5CC689CC3CB7FD10852578BF005EA759/$File/xw-hybrid-inverter-charger_installation-guide%28975-0239-01-01_rev-e%29.pdf. Thanks, Allan *Allan Sindelar* _Allan@positiveenergysolar.com_ mailto:al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician *Positive Energy, Inc.* 3201 Calle Marie Santa Fe, New Mexico 87507 *505 424-1112* _www.positiveenergysolar.com_ http://www.positiveenergysolar.com/ On 10/21/2011 2:01 PM, Gary Willett wrote: Allan: Also, you might consider using six to nine Schneider/Xantrex XW6048 inverters, or six to nine Outback Radian GS8048 inverters, in a 3-phase configuration, with a common battery bank. Also, Schneider/Xantrex has an 80A 600V charge controller that may be advantageous depending on the distance from the PV arrays to the inverters. Regards, Gary Willett, PE Icarus-Engineering LLC Icarus Solar Services LLC On 10/21/2011 10:17, Allan Sindelar wrote: Wrenches, We have been asked for a design for an off-grid system to reduce generator runtime for a mountain resort. Initial projections (consumption measurement results not yet available) suggest 15-20 kW of PV and around 30 kW of inverter capacity. However, the generators and existing wiring are three-phase 120/208. My assumption is that our only options are a set of six Sunny Islands, or 9-12 Outback GVFX3648s. Are there any other options or approaches that I'm missing? Thank you, Allan -- *Allan Sindelar* _Allan@positiveenergysolar.com_ mailto:al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician *Positive Energy, Inc.* 3201 Calle Marie Santa Fe, New Mexico 87507 *505 424-1112* _www.positiveenergysolar.com_ http://www.positiveenergysolar.com/ ___ List sponsored by Home Power magazine List Address:RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive:http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings:
Re: [RE-wrenches] intermittent battery problem
Ron, I don't think it was the water. It was probably the 10 hours they ran the generator that brought them up a bit. If the water is low, the electrolyte is more concentrated and will make the s.g seem higher. Adding water to the proper level will make the reading more accurate. I still think they are pretty sulfated. When they said they reached 29 volts in 5 minutes every morning with a charge of less than 30 amps (an assumption, since they are running a 2500 watt generator), that sounds like a battery with very little capacity. The fact that they stayed at 25.7 all day was probably because of the 800 watt PV array and light loads. It would be interesting to do a real equalization and a capacity test to see what is left of the batteries. David David Katz CTO Founder AEE Solar Inc P: 707 825-1200 F: 707 825-1202 dk...@aeesolar.com www.aeesolar.com From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ron Young Sent: Friday, October 21, 2011 11:39 AM To: RE-wrenches Subject: Re: [RE-wrenches] intermittent battery problem Hi Maverick everyone, I visited the site a couple of days ago and load tested the batteries, checked individual voltages in the string of six Surrette 4KS25's (4.3v each), checked all connections etc. The client told me that when they would go to bed battery volts read 25.7. Through the night this would seem to stay steady. About 4 a.m. as far as they could tell the voltage would drop to about 24.5. This happened without a load present and with no charging present (calm, no wind, no sun). They would start up the generator for five minutes in the morning and see the voltage come up to just above 29v then turn off the generator (a small Honda 2500) and the voltage would settly at 25.7 and remain there most of the day even when using their light loads, some lights, phone system, laptop and the Sunfrost. When checking the batteries I noticed they needed watering and mentioned this to the customer. The electrolyte was just over the plastic screen above the plates by about 1/4 inch. He said he had just watered them and always kept them filled. I replied that they were low and when he looked he said no, that's where I keep them! When I checked the specific gravity reading it was very rich reading around 1.275 - 1.280. I topped them up properly to about 1/4 inch below the bottom of the cell channel which took about 5 cups per each battery. Of course as soon as I topped them up the s.g. dropped to around 1.175. I told him to put the generator on for about ten hours and call me in the morning. I heard from the client today and in the last two days the voltage has only dropped from 25.6 to 25.4 overnight and s.g. reading is at 1.260 or better so problem seems to be solved. So it appears the battery was under watered for several years. I'm still not sure why this would result in a sudden voltage drop, especially in the middle of the night with no loads present and no charging. Any additional thoughts appreciated. Best Regards, Ron Young earthRight Products - Solareagle.comhttp://Solareagle.com On 2011-10-21, at 5:18 AM, maver...@mavericksolar.commailto:maver...@mavericksolar.com wrote: Ron, Just curious what the outcome was? Thank you, Maverick Maverick Brown BSEET, NABCEP Certified Solar PV Installer (r) President CEO Maverick Solar Enterprises, Inc. Office: 512-919-4493 Cell:512-460-9825 Sent from my HondaJet! On 2011-10-11, at 12:11 PM, Maverick Brown [Maverick Solar] wrote: Ron, Sounds like you might have a voltage drop in the system at point of measurement. A large voltage drop can happen for a few valid reasons. 1. High current demand. Trimetric or better yet PentaMetric can show this demand. 2. Poor Cable connection. Visual / Thermal inspection or local Vdc measurement along the cable chain. 3. Low to moderate current demand with low SOC. Check the MX60 Logging function to see when the last day Float happened, i.e. how many minutes of Float in the last 60 days, etc. If there are none or few, then you still might be at a low SOC. (Trimetric or better yet PentaMetric can show the SOC as well). Of course, not sure what happened to the Sunfrost, but a DC Clamp meter, might determine if it is normal now. good luck, Maverick From: re-wrenches-boun...@lists.re-wrenches.orgmailto:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ron Young Sent: Tuesday, October 11, 2011 2:00 PM To: RE-wrenches Subject: Re: [RE-wrenches] intermittent battery problem Wrenches, I received some additional info from the customer this morning. They have asked me to hold off my visit until they get a few more clues but some of what they are telling me doesn't necessarily jive with a sulphated battery. Would appreciate comments - here's a quote from their email: Hi Ron Still having
Re: [RE-wrenches] intermittent battery problem
I have been following this topic over the past couple of weeks. What Dave Katz said matches up with what I have seen over the years. Although it can be difficult to diagnose battery issues from long distance there has been a fair amount of information that points to sulfation. I think Mr. Katz is right on the money. David Palumbo Independent Power LLC 462 Solar Way Drive Hyde Park, VT 05655 www.independentpowerllc.com NABCEP Certified PV Installer Vermont Solar Partner 23 Years Experience, (802) 888-7194 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Katz Sent: Saturday, October 22, 2011 11:01 AM To: RE-wrenches Subject: Re: [RE-wrenches] intermittent battery problem Ron, I don't think it was the water. It was probably the 10 hours they ran the generator that brought them up a bit. If the water is low, the electrolyte is more concentrated and will make the s.g seem higher. Adding water to the proper level will make the reading more accurate. I still think they are pretty sulfated. When they said they reached 29 volts in 5 minutes every morning with a charge of less than 30 amps (an assumption, since they are running a 2500 watt generator), that sounds like a battery with very little capacity. The fact that they stayed at 25.7 all day was probably because of the 800 watt PV array and light loads. It would be interesting to do a real equalization and a capacity test to see what is left of the batteries. David David Katz CTO Founder AEE Solar Inc P: 707 825-1200 F: 707 825-1202 dk...@aeesolar.com www.aeesolar.com From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ron Young Sent: Friday, October 21, 2011 11:39 AM To: RE-wrenches Subject: Re: [RE-wrenches] intermittent battery problem Hi Maverick everyone, I visited the site a couple of days ago and load tested the batteries, checked individual voltages in the string of six Surrette 4KS25's (4.3v each), checked all connections etc. The client told me that when they would go to bed battery volts read 25.7. Through the night this would seem to stay steady. About 4 a.m. as far as they could tell the voltage would drop to about 24.5. This happened without a load present and with no charging present (calm, no wind, no sun). They would start up the generator for five minutes in the morning and see the voltage come up to just above 29v then turn off the generator (a small Honda 2500) and the voltage would settly at 25.7 and remain there most of the day even when using their light loads, some lights, phone system, laptop and the Sunfrost. When checking the batteries I noticed they needed watering and mentioned this to the customer. The electrolyte was just over the plastic screen above the plates by about 1/4 inch. He said he had just watered them and always kept them filled. I replied that they were low and when he looked he said no, that's where I keep them! When I checked the specific gravity reading it was very rich reading around 1.275 - 1.280. I topped them up properly to about 1/4 inch below the bottom of the cell channel which took about 5 cups per each battery. Of course as soon as I topped them up the s.g. dropped to around 1.175. I told him to put the generator on for about ten hours and call me in the morning. I heard from the client today and in the last two days the voltage has only dropped from 25.6 to 25.4 overnight and s.g. reading is at 1.260 or better so problem seems to be solved. So it appears the battery was under watered for several years. I'm still not sure why this would result in a sudden voltage drop, especially in the middle of the night with no loads present and no charging. Any additional thoughts appreciated. Best Regards, Ron Young earthRight Products - Solareagle.com On 2011-10-21, at 5:18 AM, maver...@mavericksolar.com wrote: Ron, Just curious what the outcome was? Thank you, Maverick Maverick Brown BSEET, NABCEP Certified Solar PV Installer R President CEO Maverick Solar Enterprises, Inc. Office: 512-919-4493 Cell:512-460-9825 Sent from my HondaJet! On 2011-10-11, at 12:11 PM, Maverick Brown [Maverick Solar] wrote: Ron, Sounds like you might have a voltage drop in the system at point of measurement. A large voltage drop can happen for a few valid reasons. 1. High current demand. Trimetric or better yet PentaMetric can show this demand. 2. Poor Cable connection. Visual / Thermal inspection or local Vdc measurement along the cable chain. 3. Low to moderate current demand with low SOC. Check the MX60 Logging function to see when the last day Float happened, i.e. how many minutes of Float in the last 60 days, etc. If there are none or few, then you still might be at a low SOC. (Trimetric or better yet PentaMetric can show the SOC as well). Of
[RE-wrenches] Shell solar module question
Wrenches, I received the letter below from Photon magazine. I am posting it hear because it seems like a great way to get an answer: Hi David, Over the past year, Photon magazine's German publication has been reporting on significant delamination/hotspot problems reported with Shell Solar modules (RSM and S series) in Germany, and the customer-unfriendly response of Solarworld (which inherited the warranties when it acquired Shell Solar in 2006). Now, I am trying to figure out if similar problems are happening in North America -- e.g., how many of these defective modules were sold in North America and who are some of the main installers and system owners that are potentially affected. Can you recommend any sources that can help answer some of these questions? These panels were probably sold sometime between 2000 and 2006. Thank you for your assistance, Mike Michael D. Matz PHOTON USA Corp. 514 Bryant Street San Francisco, California 94107, USA David Katz CTO Founder AEE Solar Inc P: 707 825-1200 F: 707 825-1202 dk...@aeesolar.com www.aeesolar.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Push-in Wire Connectors
Other examples of NEMA 3R enclosures are virtually all meter bases, outdoor service boxes, pole mounted disconnects, air conditioner and other roof mounted disconnects as well as wiring enclosures for changing wiring methods from underground conduits to building interiors, which generally make the connections with standard wire nuts. Electricians use NEMA 3R enclosures a lot, and don't use sealed connectors inside. As William points out, NEMA 3R may be superior to gasket sealed boxes in that 3R allows for any condensation to evaporate readily. Drake Chamberlin ATHENS ELECTRIC LLC OH License 44810 CO license 3773 NABCEP Certified PV ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] intermittent battery problem
I've seen behavior like that from Series 5000 Rolls that were only a year old, but chronically under charged. (20 amp load and the inverter would reach low shut off in minutes, 30 amp charge and it hit high voltage and quit charging) Any other battery, and I would assume its capacity was gone. It seems to be something about their slightly different alloy in the plates, but I don't know for sure. Enough time held at high enough voltage, and they seem to recover, but its definitely concerning to have a 1000 AH battery behave like a 10 AH battery. I found that if the voltage is held at the high side, that the charging amps would actually increase over time, which is opposite of other batteries. It must have a coating of sulfation on the plates that initially keeps the battery from working right, then with enough time it knocks that layer off to expose the actual plates and begin actual charging. (just a guess) I'll actually set the charge amps down, and the voltage up at first, then when I see it start taking more amps, I set it back to normal charge parameters. Ray On 10/22/2011 9:01 AM, David Katz wrote: When they said they reached 29 volts in 5 minutes every morning with a charge of less than 30 amps (an assumption, since they are running a 2500 watt generator), that sounds like a battery with very little capacity. David Katz ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] intermittent battery problem; ...Battery Sulfation
Hi Ron, As many on this list have suggested, it sounds like a sulfated battery condition. In your last message you revealed something to me that absolutely confirms this but perhaps you didn't recognize it. Battery voltage readings are deceiving because they do not indicate capacity. 25.7 volts sounds like a fully charged 24 volt bank, but is it? Only if the battery was at rest for 5-6 hours could you have some confidence that the bank was full at this voltage. But this is not the case because the bank is in daily use, always charging or discharging. However, there is one useful indication that voltage can be used for: detecting a sulfated battery. You mentioned that the the battery drops to 24.5 in the early AM without any heavy loads on. For the 4KS25 battery this equates to about 800AH at the 72 hour rate. Then you said that the customer ran a 2500 watt generator for 5 minutes and drove the voltage up to 29 volts. Here's the Ah-Ha moment: That is EXACTLY the behavior of a heavily sulfated battery bank. A fast rise in voltage indicates sulfation. It is impossible for that tiny generator, or any charge source they own for that matter, to replace the hundreds of AH it would take to drive a healthy battery up to the absorb voltage of 29 volts. The bank is about 45,000 watt hours (72h rate). There would have to be over 20,000 Wh removed to be at that voltage. How many Wh's are replaced in 5 minutes by a 2500 watt genny? I'm sure you are getting the picture. Why did this happen to these expensive batteries? Glad you asked. Battery plates are not uniformly efficient in the electrochemical process leaving some portions with lead sulfate even after 8 hours of charging. Unless these portions are cleared off regularly by achieving 100% SoC and occasional, thorough equalization, the amorphous sulfate will convert to a crystalline form and grow. 99% charge, if not corrected in time, will always cause premature battery failure. Undersized RE charging systems, or perhaps oversized batteries, is the culprit that contributes to this all too frequent phenomenon of chronic undercharging. I say contribute because there are other factors. Fact: it can take 10-12 hours to fully charge a lead acid battery. Fact: The time element of battery charging is a highly misunderstood part. With only a few daily sun-hours to work with, how do we get a battery charged with PV solar? Properly sizing the PV array to the battery AND consumption is critical. One method I think is essential for nearly all PV systems is use a generator and charger, appropriately sized to the battery. By bulk charging early in the AM you can reduce the finish time to perhaps 5-6 hours of constant voltage charging, something easily done with a PV system. Ron, you might be able to recover some capacity in this bank if the sulfate has not formed hard crystals by now. You can try a very long charge time, up to 24 hours, at high voltage, about 31 volts. You will need a larger generator. Monitor the temperature and reduce current if they get up to 125F internal. In our shop I have recovered sulfated batteries with high voltage charging, as much as 3Vpc (do not do this with any loads connected), at reduced current, about C*.05, and a 1 kHz pulser that I built. My findings over the years is the current will begin to rise very slowly, peak then drop if the recovery is working. Sorry that this post is getting so long. There's just so much. OK, one last thing. In my last post to you I recommended a battery AH monitor. This problem could have been detected and perhaps prevented if they had one. Larry Crutcher Starlight Solar Power Systems On Oct 21, 2011, at 11:39 AM, Ron Young wrote: Hi Maverick everyone, I visited the site a couple of days ago and load tested the batteries, checked individual voltages in the string of six Surrette 4KS25's (4.3v each), checked all connections etc. The client told me that when they would go to bed battery volts read 25.7. Through the night this would seem to stay steady. About 4 a.m. as far as they could tell the voltage would drop to about 24.5. This happened without a load present and with no charging present (calm, no wind, no sun). They would start up the generator for five minutes in the morning and see the voltage come up to just above 29v then turn off the generator (a small Honda 2500) and the voltage would settly at 25.7 and remain there most of the day even when using their light loads, some lights, phone system, laptop and the Sunfrost. When checking the batteries I noticed they needed watering and mentioned this to the customer. The electrolyte was just over the plastic screen above the plates by about 1/4 inch. He said he had just watered them and always kept them filled. I replied that they were low and when he looked he said no, that's where I keep them! When I checked the specific gravity reading it was very rich reading
