Re: [RE-wrenches] On demand WH
Hi Bill, et al, There are two major categories of tankless water heaters-natural draft (which work very similar in control aspect to a conventional tank i.e.. no electric required, some form of pilot light) and power vented (all power vented machines have need for at least a fan, most a computer with some form of display included - if your own body is incapable of telling you if the water is sufficiently hot). Of the Big Five (major players in the tankless market) all manufacture one or more models of power vented tankless. Today, only Bosch markets a natural draft tankless. Bosch offers more than one model of natural draft tankless, standing pilot and intermittent pilot. If you like simple, trouble free, and low life cycle cost, you have but one choice. http://www.bosch-climate.us/files/201304181918370.520PN_English_06.2011.pdf What must be properly addressed with _any_ tankless is intake and exhaust venting, gas line sizing, and water quality. Since this isn't a tank, the pilot flame does almost nothing in terms of freeze prevention. Some manufacturers state flow rate for their heaters without also providing temp rise. Flow rate without temp rise is meaningless. The above is a 117,000 BTU/h machine. Sometimes winter ground water temperatures are significantly colder than summertime temps. If you want hot water in the winter, too, make sure you use the appropriate temp rise. Hardness is the biggest issue with water quality, if you scale the heat exchanger you won't get the performance advertised. If you have hard water, a water softener or descaling _as required_ is necessary. I am a big fan of tankless and have been since '89 when I was first introduced to them as a user. Today, I install and troubleshoot all five major manufacturers. Co-located with the load, tankless provides you not only endless hot water but also instant hot water. Good luck, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 On Sat, Sep 28, 2013 at 10:19 PM, frenergy wrote: Off-grid Wrenches, I'm working on a load sheet and am having a hard time finding standby and while firing electrical usage for a propane-fired on demand water heater. Do they some/all have standing pilots, glow bars, something else? I'm guessing the standby power needs are very low but we all know how even 10-15 watts adds up over 24 hrs when you're off-grid. If any body has some actual numbers rather than just pdf.specs (though manus specs might help some), I would be most grateful. Thanks in advance. Bill Feather River Solar Electric -- ___ List sponsored by Home Power magazine ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] On demand WH
As concerns standby loss, I can't speak to the others, but the Rinnai has a simple on/off button on the front of the unit. A remote controller is available which also provides the switch. It does take afew seconds for the unit to boot up. Up to three remotes may be installed, making the on /off operation and temperature adjustment fairly convenient. Been using a Rinnai here, on grid for 10 years or so. It works. We like it. I understand a pilot uses a significant amount of gas over the course of a year. Just sayin'. Dick Ratico Solarwind Electric --- You wrote: If its a Rinai, I measured one once that was 30 watts AC standby, and jumped a bit higher when firing. It also needed pure sine. The customer swapped it for a regular hot water tank. Some Bosches and old Palomas, etc. had either a piezo ignition or pilot, but took no power. I'm working on a system with one now that needs 12vdc at about 5 watts. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 --- end of quote --- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] On demand WH
Hi Bill, I'm still running an Aquastar 125BS (original French model, before Bosch bought them) that I installed in 1990. I've had to rebuild the water valve once (after a freeze up; it's in an unheated outside closet on the north side of my house), the high-temp sensor once, and I needed to replace the thermocouple a few times when I was just using a small propane tank to run it. I installed a 250 gallon propane tank in the late nineties and haven't had to replace the thermocouple since. The Aquastar still works great, even when my incoming water temp is near freezing. I just have to use less cold-water mix during the winter. Are you finding the new Bosch models to be this reliable? Brian Teitelbaum AEE Solar -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Loesch Sent: Monday, September 30, 2013 5:00 AM To: RE-wrenches Subject: Re: [RE-wrenches] On demand WH Hi Bill, et al, There are two major categories of tankless water heaters-natural draft (which work very similar in control aspect to a conventional tank i.e.. no electric required, some form of pilot light) and power vented (all power vented machines have need for at least a fan, most a computer with some form of display included - if your own body is incapable of telling you if the water is sufficiently hot). Of the Big Five (major players in the tankless market) all manufacture one or more models of power vented tankless. Today, only Bosch markets a natural draft tankless. Bosch offers more than one model of natural draft tankless, standing pilot and intermittent pilot. If you like simple, trouble free, and low life cycle cost, you have but one choice. http://www.bosch-climate.us/files/201304181918370.520PN_English_06.2011.pdf What must be properly addressed with _any_ tankless is intake and exhaust venting, gas line sizing, and water quality. Since this isn't a tank, the pilot flame does almost nothing in terms of freeze prevention. Some manufacturers state flow rate for their heaters without also providing temp rise. Flow rate without temp rise is meaningless. The above is a 117,000 BTU/h machine. Sometimes winter ground water temperatures are significantly colder than summertime temps. If you want hot water in the winter, too, make sure you use the appropriate temp rise. Hardness is the biggest issue with water quality, if you scale the heat exchanger you won't get the performance advertised. If you have hard water, a water softener or descaling _as required_ is necessary. I am a big fan of tankless and have been since '89 when I was first introduced to them as a user. Today, I install and troubleshoot all five major manufacturers. Co-located with the load, tankless provides you not only endless hot water but also instant hot water. Good luck, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 On Sat, Sep 28, 2013 at 10:19 PM, frenergy wrote: Off-grid Wrenches, I'm working on a load sheet and am having a hard time finding standby and while firing electrical usage for a propane-fired on demand water heater. Do they some/all have standing pilots, glow bars, something else? I'm guessing the standby power needs are very low but we all know how even 10-15 watts adds up over 24 hrs when you're off-grid. If any body has some actual numbers rather than just pdf.specs (though manus specs might help some), I would be most grateful. Thanks in advance. Bill Feather River Solar Electric -- ___ List sponsored by Home Power magazine ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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 Change email address 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] On demand WH
Brian; I have had that same aquastar 125 here since 1998. All I've had to do is clean out the air filter every 3 years or so, and replace the magnetic temp sensor switch once. I have clients up in Canada who have 5-6 of the Bosch units at a remote fly-in fishing campmost are actually mounted outdoors on showerhouses etc. No problems if you drain them for the winter. BUT standing by for a satellite service call from themsomething is clogged. My guess is they have a sediment problem. The internal sediment sieve in the Bosch is very fine mesh. My main observation on the Bosch vs aquastar is that the new Bosch pilot is MUCH easier to light and keep lit. Dan Fink, Executive Director; Otherpower Buckville Energy Consulting Buckville Publications LLC NABCEP / IREC accredited Continuing Education Providers 970.672.4342 On Mon, Sep 30, 2013 at 10:39 AM, Brian Teitelbaum bteitelb...@aeesolar.com wrote: Hi Bill, I'm still running an Aquastar 125BS (original French model, before Bosch bought them) that I installed in 1990. I've had to rebuild the water valve once (after a freeze up; it's in an unheated outside closet on the north side of my house), the high-temp sensor once, and I needed to replace the thermocouple a few times when I was just using a small propane tank to run it. I installed a 250 gallon propane tank in the late nineties and haven't had to replace the thermocouple since. The Aquastar still works great, even when my incoming water temp is near freezing. I just have to use less cold-water mix during the winter. Are you finding the new Bosch models to be this reliable? Brian Teitelbaum AEE Solar -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto: re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Loesch Sent: Monday, September 30, 2013 5:00 AM To: RE-wrenches Subject: Re: [RE-wrenches] On demand WH Hi Bill, et al, There are two major categories of tankless water heaters-natural draft (which work very similar in control aspect to a conventional tank i.e.. no electric required, some form of pilot light) and power vented (all power vented machines have need for at least a fan, most a computer with some form of display included - if your own body is incapable of telling you if the water is sufficiently hot). Of the Big Five (major players in the tankless market) all manufacture one or more models of power vented tankless. Today, only Bosch markets a natural draft tankless. Bosch offers more than one model of natural draft tankless, standing pilot and intermittent pilot. If you like simple, trouble free, and low life cycle cost, you have but one choice. http://www.bosch-climate.us/files/201304181918370.520PN_English_06.2011.pdf What must be properly addressed with _any_ tankless is intake and exhaust venting, gas line sizing, and water quality. Since this isn't a tank, the pilot flame does almost nothing in terms of freeze prevention. Some manufacturers state flow rate for their heaters without also providing temp rise. Flow rate without temp rise is meaningless. The above is a 117,000 BTU/h machine. Sometimes winter ground water temperatures are significantly colder than summertime temps. If you want hot water in the winter, too, make sure you use the appropriate temp rise. Hardness is the biggest issue with water quality, if you scale the heat exchanger you won't get the performance advertised. If you have hard water, a water softener or descaling _as required_ is necessary. I am a big fan of tankless and have been since '89 when I was first introduced to them as a user. Today, I install and troubleshoot all five major manufacturers. Co-located with the load, tankless provides you not only endless hot water but also instant hot water. Good luck, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 On Sat, Sep 28, 2013 at 10:19 PM, frenergy wrote: Off-grid Wrenches, I'm working on a load sheet and am having a hard time finding standby and while firing electrical usage for a propane-fired on demand water heater. Do they some/all have standing pilots, glow bars, something else? I'm guessing the standby power needs are very low but we all know how even 10-15 watts adds up over 24 hrs when you're off-grid. If any body has some actual numbers rather than just pdf.specs (though manus specs might help some), I would be most grateful. Thanks in advance. Bill Feather River Solar Electric -- ___ List sponsored by Home Power magazine ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
Re: [RE-wrenches] Using legacy modules on micro-inverters
Nick: What is the upper voltage limit for the M250? What happens when that voltage is exceeded? I am trying to use Siemens SP75 modules (two in series) and Shell SQ-150-PC. Below are the specs. Note that two SP75s in series, if you multiply the voltages by two, is identical to the SQ-150 except for the temperature compensation. I am not sure what to do with the temperature compensation value if I put two SP175s insereis. Do you know? Qty Watts Ext Watts Pmax Vpmax Ipmax Isc Voc Temp Coefficient of Voc Siemens PC4JF (Same as the SP75?) 12 75 900 75 75 17 4.4 4.8 21.7 -0.077 Shell SQ-150 3 150 450 150 150 34 4.4 4.8 43.4 -0.161 Our record low is -10 C and average high is 38C. If I enter the data for the Shell, the calculator shows they are compatible with the M250. Entering the data for two SP75s using -0.077 for Temp Comp (SP75) the tool says not. If I use double (-0.154), then the two SP75s are compatible. What is your determination? Thanks, William From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Nick Soleil Sent: Monday, September 30, 2013 9:56 AM To: RE-wrenches Subject: Re: [RE-wrenches] Using legacy modules on micro-inverters Hi wrenches, The M250 is not limited to 60 cell modules only. The M250 has an expanded voltage window which will allow for it to be paired with a wider range of modules. Enphase has an online module compatibility calculator which can be used for checking a specific pairing in a specific location, at: http://enphase.com/module-compatibility-calculator-m250-update/. Keep in mind that many of the high efficiency, higher voltage, 72 cell modules will not be compatible. On Sat, Sep 28, 2013 at 6:45 AM, Jay Peltz j...@asis.com wrote: Hi Bill Is there a new M250? Enphase shows the 250 at 48vdc max and states 60 cell only modules. That would be nice if it did both Jay Peltz power. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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-wrenches] Generator automatic disconnect
Wrenches, I want to use the Ecogen 6kW generator on a large off grid system. The location has very few overcast or rainy days and the generator will rarely be needed. My concerns is nuisance tripping the generator output breakers if the household load exceeds 6kW. The power system control has a feature for reducing the AC current used to charge the batteries but does not have a feature for disconnecting the AC input based on input load. Does anyone have a solution for monitoring AC load from the generator and disconnect it if overloaded? It must automatically reconnect after a short timeout. Thank you, Larry Crutcher ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] Using legacy modules on micro-inverters
Hi Wiliam, The max voltage rating of the M250 is 48V. When you ran the compatibility checker, did you use 154mv/°C? You can either input the mV/°C or the %/°C. You will need to be sure that you convert the 0.154 to 154mV. On Mon, Sep 30, 2013 at 12:24 PM, William Miller will...@millersolar.comwrote: Nick: ** ** What is the upper voltage limit for the M250? What happens when that voltage is exceeded? ** ** I am trying to use Siemens SP75 modules (two in series) and Shell SQ-150-PC. Below are the specs. Note that two SP75s in series, if you multiply the voltages by two, is identical to the SQ-150 except for the temperature compensation. I am not sure what to do with the temperature compensation value if I put two SP175s insereis. Do you know? ** ** ** ** *Qty* *Watts* *Ext* *Watts* *Pmax* *Vpmax* *Ipmax* *Isc* *Voc* *Temp Coefficient of Voc* Siemens PC4JF (Same as the SP75?) 12 75 900 75 75 17 4.4 4.8 21.7 -0.077 Shell SQ-150 3 150 450 150 150 34 4.4 4.8 43.4 -0.161 ** ** Our record low is -10 C and average high is 38C. ** ** If I enter the data for the Shell, the calculator shows they are compatible with the M250. Entering the data for two SP75s using -0.077 for Temp Comp (SP75) the tool says not. If I use double (-0.154), then the two SP75s are compatible. What is your determination? ** ** Thanks, ** ** William ** ** ** ** ** ** *From:* re-wrenches-boun...@lists.re-wrenches.org [mailto: re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Nick Soleil *Sent:* Monday, September 30, 2013 9:56 AM *To:* RE-wrenches *Subject:* Re: [RE-wrenches] Using legacy modules on micro-inverters ** ** Hi wrenches, The M250 is not limited to 60 cell modules only. The M250 has an expanded voltage window which will allow for it to be paired with a wider range of modules. Enphase has an online module compatibility calculator which can be used for checking a specific pairing in a specific location, at: http://enphase.com/module-compatibility-calculator-m250-update/. Keep in mind that many of the high efficiency, higher voltage, 72 cell modules will not be compatible. ** ** ** ** On Sat, Sep 28, 2013 at 6:45 AM, Jay Peltz j...@asis.com wrote: Hi Bill ** ** Is there a new M250? Enphase shows the 250 at 48vdc max and states 60 cell only modules. ** ** That would be nice if it did both ** ** Jay ** ** Peltz power. ** ** ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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 -- Cordially, *Nick Soleil* *Field Applications Engineer * *Enphase Energy* Mobile: (707) 321-2937 ** *Enphase Commercial Solar.* *Limitless.*http://www.enphase.com/commercial?utm_source=emailutm_medium=sigutm_campaign=Comm2012 * *http://www.enphase.com/commercial?utm_source=emailutm_medium=sigutm_campaign=Comm2012 1420 North McDowell Petaluma, CA 94954 www.enphase.com http://www.enphaseenergy.com/ P: (707) 763-4784 x7267 F: (707) 763-0784 E: nsol...@enphaseenergy.com [image: nabcep logo] Certified Solar PV Installer #03262011-300 “Don’t get me wrong: I love nuclear energy! It’s just that I prefer fusion to fission. And it just so happens that there’s an enormous fusion reactor safely banked a few million miles from us. It delivers more than we could ever use in just about 8 minutes. And it’s wireless! .” - William McDonough This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message in error, please contact the sender by reply email and destroy all copies of the original message. image002.jpg___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] On demand WH
All, We are finding, with rare exception, that despite claims by On Demand manufactures of their units being, solar compatible most do not reach the common sense definition of being so. I would suggest anyone installing a solar preheat tank before an on demand talk to no less than two people from the manufacture to confirm the nature of the solar compatibility and get a plumbing diagram from them as well. We like the Takagi as it seems to be truly solar compatible. Many of our clients have light switches installed to facilitate easily turning the unit on or off so in the summer they can get rid of needless short cycling or any phantom load. But, honestly, for conventional homes we have moved away from advocating for on demands thinking standby heat loss for an occupied homes is so little that the expense of the 'maybe energy saving device', by and large does not warrant its use in these situations. Thanks, Andrew Koyaanisqatsi President Solar Energy Solutions, Inc. Since 1987, Moving Portland and Beyond to an Environmentally Sustainable Future. 503-238-4502 http://www.solarenergyoregon.com/ Better one's House too little one day than too big all the Year after. From: Brian Teitelbaum bteitelb...@aeesolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Monday, September 30, 2013 9:39 AM Subject: Re: [RE-wrenches] On demand WH Hi Bill, I'm still running an Aquastar 125BS (original French model, before Bosch bought them) that I installed in 1990. I've had to rebuild the water valve once (after a freeze up; it's in an unheated outside closet on the north side of my house), the high-temp sensor once, and I needed to replace the thermocouple a few times when I was just using a small propane tank to run it. I installed a 250 gallon propane tank in the late nineties and haven't had to replace the thermocouple since. The Aquastar still works great, even when my incoming water temp is near freezing. I just have to use less cold-water mix during the winter. Are you finding the new Bosch models to be this reliable? Brian Teitelbaum AEE Solar -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Loesch Sent: Monday, September 30, 2013 5:00 AM To: RE-wrenches Subject: Re: [RE-wrenches] On demand WH Hi Bill, et al, There are two major categories of tankless water heaters-natural draft (which work very similar in control aspect to a conventional tank i.e.. no electric required, some form of pilot light) and power vented (all power vented machines have need for at least a fan, most a computer with some form of display included - if your own body is incapable of telling you if the water is sufficiently hot). Of the Big Five (major players in the tankless market) all manufacture one or more models of power vented tankless. Today, only Bosch markets a natural draft tankless. Bosch offers more than one model of natural draft tankless, standing pilot and intermittent pilot. If you like simple, trouble free, and low life cycle cost, you have but one choice. http://www.bosch-climate.us/files/201304181918370.520PN_English_06.2011.pdf What must be properly addressed with _any_ tankless is intake and exhaust venting, gas line sizing, and water quality. Since this isn't a tank, the pilot flame does almost nothing in terms of freeze prevention. Some manufacturers state flow rate for their heaters without also providing temp rise. Flow rate without temp rise is meaningless. The above is a 117,000 BTU/h machine. Sometimes winter ground water temperatures are significantly colder than summertime temps. If you want hot water in the winter, too, make sure you use the appropriate temp rise. Hardness is the biggest issue with water quality, if you scale the heat exchanger you won't get the performance advertised. If you have hard water, a water softener or descaling _as required_ is necessary. I am a big fan of tankless and have been since '89 when I was first introduced to them as a user. Today, I install and troubleshoot all five major manufacturers. Co-located with the load, tankless provides you not only endless hot water but also instant hot water. Good luck, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 On Sat, Sep 28, 2013 at 10:19 PM, frenergy wrote: Off-grid Wrenches, I'm working on a load sheet and am having a hard time finding standby and while firing electrical usage for a propane-fired on demand water heater. Do they some/all have standing pilots, glow bars, something else? I'm guessing the standby power needs are very low but we all know how even 10-15 watts adds up over 24 hrs when you're off-grid. If any body has some actual numbers rather than just pdf.specs (though manus specs might help some), I would be most grateful. Thanks in advance. Bill
Re: [RE-wrenches] Generator automatic disconnect
Larry: Maybe a better approach might be to use an inverter with Gen-support. That is unless a system already exists that does not have this feature. Plan B: use the gen start signal to disable one or more of the larger loads. I know this is not what you asked for, just trying inject some different ideas. William -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Larry Crutcher, Starlight Solar Power Systems Sent: Monday, September 30, 2013 1:02 PM To: RE-wrenches Subject: [RE-wrenches] Generator automatic disconnect Wrenches, I want to use the Ecogen 6kW generator on a large off grid system. The location has very few overcast or rainy days and the generator will rarely be needed. My concerns is nuisance tripping the generator output breakers if the household load exceeds 6kW. The power system control has a feature for reducing the AC current used to charge the batteries but does not have a feature for disconnecting the AC input based on input load. Does anyone have a solution for monitoring AC load from the generator and disconnect it if overloaded? It must automatically reconnect after a short timeout. Thank you, Larry Crutcher _ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] Generator automatic disconnect
Why not utilize the Generac Smart switch and load management module? It will disconnect up to four circuits based on load. On Mon, Sep 30, 2013 at 4:02 PM, Larry Crutcher, Starlight Solar Power Systems la...@starlightsolar.com wrote: Wrenches, I want to use the Ecogen 6kW generator on a large off grid system. The location has very few overcast or rainy days and the generator will rarely be needed. My concerns is nuisance tripping the generator output breakers if the household load exceeds 6kW. The power system control has a feature for reducing the AC current used to charge the batteries but does not have a feature for disconnecting the AC input based on input load. Does anyone have a solution for monitoring AC load from the generator and disconnect it if overloaded? It must automatically reconnect after a short timeout. Thank you, Larry Crutcher ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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 -- Chris Mason President, Comet Systems Ltd www.cometenergysystems.com Cell: 264.235.5670 Skype: netconcepts ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] Generator automatic disconnect
3rd option would be to have a separate charger (IOTA) that just runs from the generator. No pass through loads to the generator. 4th option would be to use a larger Kohler for backup. My experience is that even if they don't think they'll need it, they eventually will actually use it. Large off grid systems tend to creep ever larger. I'd look at all the scenarios with pricing, and pros and cons. You'll see what makes sense. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 9/30/2013 5:14 PM, William Miller wrote: Larry: Maybe a better approach might be to use an inverter with Gen-support. That is unless a system already exists that does not have this feature. Plan B: use the gen start signal to disable one or more of the larger loads. I know this is not what you asked for, just trying inject some different ideas. William -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Larry Crutcher, Starlight Solar Power Systems Sent: Monday, September 30, 2013 1:02 PM To: RE-wrenches Subject: [RE-wrenches] Generator automatic disconnect Wrenches, I want to use the Ecogen 6kW generator on a large off grid system. The location has very few overcast or rainy days and the generator will rarely be needed. My concerns is nuisance tripping the generator output breakers if the household load exceeds 6kW. The power system control has a feature for reducing the AC current used to charge the batteries but does not have a feature for disconnecting the AC input based on input load. Does anyone have a solution for monitoring AC load from the generator and disconnect it if overloaded? It must automatically reconnect after a short timeout. Thank you, Larry Crutcher _ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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 Change email address 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] Using legacy modules on micro-inverters
William, PV temperature coefficient of voltage is a function of the number of cells in series. For 72 cell PV (or two 36-cell PV in series), the coefficient is 2X that of 36 cells. Two SP75 in series, in an ambient temperature environment of -10C, and presuming a cell temperature of -10C at reduced light and a low solar altitude to minimize cell heating, would exhibit nominally 45.4Voc, and 35.6Vmpp respectively. Two SP75 in series, in an ambient temperature environment of 38C, and presuming 1000 W/m^2 orthogonal to the PV module at solar noon, would yield nominally 36.6Voc, and 28.7Vmpp respectively. Nominal cell temperature under the latter circumstances would be 69.3C, presuming a rooftop mount, 6-8 above the roof surface, with 1.5 m/s or less wind speed, and perfectly orthogonal to the sun at solar zenith. Two SQ150 under the identical cold ambient conditions would exhibit 44.4 Voc, and 34.8Vmpp. Two SQ150 under the identical hot ambient conditions would exhibit 36.1Voc, and 28.3Vmpp. Nominal cell temperature for the SQ150 under the latter circumstances would be 70.5C, with the same presumptions as above. Very slight differences exist between two SP75 in series, and one SQ150, but as you alluded to below, they're close enough to be considered essentially identical. Regards, Dan On Mon, 9/30/13, William Miller will...@millersolar.com wrote: Subject: Re: [RE-wrenches] Using legacy modules on micro-inverters To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Date: Monday, September 30, 2013, 2:24 PM Nick: What is the upper voltage limit for the M250? What happens when that voltage is exceeded? I am trying to use Siemens SP75 modules (two in series) and Shell SQ-150-PC. Below are the specs. Note that two SP75s in series, if you multiply the voltages by two, is identical to the SQ-150 except for the temperature compensation. I am not sure what to do with the temperature compensation value if I put two SP175s insereis. Do you know? Our record low is -10 C and average high is 38C. If I enter the data for the Shell, the calculator shows they are compatible with the M250. Entering the data for two SP75s using -0.077 for Temp Comp (SP75) the tool says not. If I use double (-0.154), then the two SP75s are compatible. What is your determination? Thanks, William From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Nick Soleil Sent: Monday, September 30, 2013 9:56 AM To: RE-wrenches Subject: Re: [RE-wrenches] Using legacy modules on micro-inverters Hi wrenches,The M250 is not limited to 60 cell modules only. The M250 has an expanded voltage window which will allow for it to be paired with a wider range of modules. Enphase has an online module compatibility calculator which can be used for checking a specific pairing in a specific location, at: http://enphase.com/module-compatibility-calculator-m250-update/. Keep in mind that many of the high efficiency, higher voltage, 72 cell modules will not be compatible. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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] Generator automatic disconnect
Larry, one other consideration: My own Ecogen appears to be able to produce well over its rating. I have never had an amp-clamp with me when I have observed this, but it appears to be quite able to do so. My Magnum 4024 will charge at 114A (as measured on a TriMetric 2025) at 28V DC, or 3,200 watts after efficiency losses, while at the same time passing through both microwave and toaster, which are both being run directly off of the gennie as pass-through loads, as the TM's amps in doesn't diminish significantly. Note that this is at 6,700' elevation, which would suggest about a 23% derating, or about 4,600 watts available. I'm sorry to not be more precise - I really should test it. But the point is that you may have more headroom than you think. My output breaker is 50A 1P, so I assume the 240V option would be 25A 2P. You might consider increasing this to 30A if your concern is nuisance tripping. Also, the QO breakers have a trip curve to allow minor surges. Allan Allan Sindelar al...@positiveenergysolar.com NABCEP Certified PV Installation Professional NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder, Positive Energy, Inc. A Certified B CorporationTM 3209 Richards Lane Santa Fe, New Mexico 87507 505 424-1112 office 780-2738 cell www.positiveenergysolar.com On 9/30/2013 5:38 PM, Ray Walters wrote: 3rd option would be to have a separate charger (IOTA) that just runs from the generator. No pass through loads to the generator. 4th option would be to use a larger Kohler for backup. My experience is that even if they don't think they'll need it, they eventually will actually use it. Large off grid systems tend to creep ever larger. I'd look at all the scenarios with pricing, and pros and cons. You'll see what makes sense. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 9/30/2013 5:14 PM, William Miller wrote: Larry: Maybe a better approach might be to use an inverter with "Gen-support." That is unless a system already exists that does not have this feature. Plan B: use the gen start signal to disable one or more of the larger loads. I know this is not what you asked for, just trying inject some different ideas. William -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Larry Crutcher, Starlight Solar Power Systems Sent: Monday, September 30, 2013 1:02 PM To: RE-wrenches Subject: [RE-wrenches] Generator automatic disconnect Wrenches, I want to use the Ecogen 6kW generator on a large off grid system. The location has very few overcast or rainy days and the generator will rarely be needed. My concerns is nuisance tripping the generator output breakers if the household load exceeds 6kW. The power system control has a feature for reducing the AC current used to charge the batteries but does not have a feature for disconnecting the AC input based on input load. Does anyone have a solution for monitoring AC load from the generator and disconnect it if overloaded? It must automatically reconnect after a short timeout. Thank you, Larry Crutcher _ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings:
Re: [RE-wrenches] Using legacy modules on micro-inverters
Dan: Thanks very much for the detailed analysis. So the short answer is that a 48 v micro-inverter will be compatible with either module. I am old school and like a little more head room than that, especially since we have not learned yet if inverter damage will occur on overvoltage. I am anxious to try the Power One units. Anyone else tried these yet? William -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Exeltech Sent: Monday, September 30, 2013 6:01 PM To: RE-wrenches Subject: Re: [RE-wrenches] Using legacy modules on micro-inverters William, PV temperature coefficient of voltage is a function of the number of cells in series. For 72 cell PV (or two 36-cell PV in series), the coefficient is 2X that of 36 cells. Two SP75 in series, in an ambient temperature environment of -10C, and presuming a cell temperature of -10C at reduced light and a low solar altitude to minimize cell heating, would exhibit nominally 45.4Voc, and 35.6Vmpp respectively. Two SP75 in series, in an ambient temperature environment of 38C, and presuming 1000 W/m^2 orthogonal to the PV module at solar noon, would yield nominally 36.6Voc, and 28.7Vmpp respectively. Nominal cell temperature under the latter circumstances would be 69.3C, presuming a rooftop mount, 6-8 above the roof surface, with 1.5 m/s or less wind speed, and perfectly orthogonal to the sun at solar zenith. Two SQ150 under the identical cold ambient conditions would exhibit 44.4 Voc, and 34.8Vmpp. Two SQ150 under the identical hot ambient conditions would exhibit 36.1Voc, and 28.3Vmpp. Nominal cell temperature for the SQ150 under the latter circumstances would be 70.5C, with the same presumptions as above. Very slight differences exist between two SP75 in series, and one SQ150, but as you alluded to below, they're close enough to be considered essentially identical. Regards, Dan ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address 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
