Re: [RE-wrenches] NEC compliant solar labels
Hi Joel, I believe AEE sells them as well, jay peltz power On Nov 21, 2008, at 12:42 PM, Joel Davidson wrote: Tyco makes solar labels. See www.tycoelectronics.com/AboutUs/news/getpdf.asp?id=1363&f=solar_labels_flyer_final.pdf At least one reseller offers the labels. See http://store.altenergystore.com/Enclosures-Electrical-and-Safety/NEC-Compliant-Safety-Labels/NEC-Compliant-Grid-Tie-Safety-Labels/p6618/ ___ 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
Re: [RE-wrenches] DC Rating of Disconnects
The only thing I am aware of wrt to fused DC discos is the notion that PV runs that penetrate a building shell need over current protection. The City of Santa Monica used to (and may still) have this requirement. The (non) issues as I understand them: (1) PV modules should be treated as any other independent source, regardless of the fact that they are inherently current limited. It would be straightforward to determine whether or not the wire used has the adequate ampacity. (2) Inverters may be capable of back-feeding the PV array . Manufacturers that continue to sell and market a specific inverter model, are usually willing to write a letter to the effect that back-feeding will not occur. The only mfgr that I know of that demurred is Sharp wrt their JH-3500, and it is no longer sold in the US. Of course the use of an unfused disco makes good sense, prior to penetrating building shell. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ASAP POWER! 2 Sent: Friday, November 21, 2008 10:47 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] DC Rating of Disconnects In 2008, we have had to replace our standard Sq. D HU361RB used since our beginnings, with the Sq. D H361RB (U stands for unfused). Was there some sort of code change NEC or CBC maybe that made most jurisdictions in So Cal suddenly start requiring fused DC disconnects? Typically, we fill the fused Sq. D. box with 15A 5" fuses. Peter D. _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Miller Sent: Friday, November 21, 2008 9:43 AM To: RE-wrenches Subject: Re: [RE-wrenches] DC Rating of Disconnects Peter: I am resending, the first version inexplicably deleted some text: An arc is created in the process of disconnecting any current under load. DC circuits have an enhanced ability to sustain that arc. PV circuits exacerbate this problem as a short or load is disconnected because they can sustain a short but the voltage rises drastically as a circuit is disconnected. This all justifies the added expense of a DC rated disconnect. We use the Square D HU361 without hesitation. There are few alternatives available and none with any significant cost savings. In selecting a disconnect, a design-build contractor must use the highest Voc possible. Make sure you are entering the 690.7 table with the record low temperature for the location. If we used a disconnect without the correct rating we would open ourselves to unacceptable liability exposure and, worse yet, would not experience that pleasant feeling one gets when you know you've done the job right. William Miller At 09:11 AM 11/21/2008, you wrote: _ From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesnt come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. >From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President ___ 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] NEC compliant solar labels
Ahhh yes... I love this NEC signage requirement. It goes a long way toward re-assuring inspectors and others that the inverter does a reliable job disconnecting if the grid goes down. I will put this at the top of my 690 improvement list. Along the same lines: we oughta sell lightbulb base stoppers to keep all those electrons from leaking out of lamps without bulbs! ;-) Have great weekends all my fellow wrenches! Its a cold but clear day here and I'm gonna go home and cut firewood and play guitar hero with my kids. For a brighter energy future, Geoff Greenfield Founder and CEO Third Sun Solar & Wind Power Ltd. 340 West State Street, Unit 25 Athens, OH 45701 740.597.3111 Fax 740.597.1548 www.Third-Sun.com Clean Energy - Expertly Installed - "Joel Davidson" <[EMAIL PROTECTED]> wrote: > > Tyco makes solar labels. See www. tyco electronics.com/AboutUs/news/getpdf.asp?id=1363&f= solar _ labels _flyer_final.pdf At least one reseller offers the labels. See http://store.altenergystore.com/Enclosures-Electrical-and-Safety/NEC-Compliant-Safety-Labels/NEC-Compliant-Grid-Tie-Safety-Labels/p6618/ > ___ 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
[RE-wrenches] NEC compliant solar labels
Tyco makes solar labels. See www.tycoelectronics.com/AboutUs/news/getpdf.asp?id=1363&f=solar_labels_flyer_final.pdf At least one reseller offers the labels. See http://store.altenergystore.com/Enclosures-Electrical-and-Safety/NEC-Compliant-Safety-Labels/NEC-Compliant-Grid-Tie-Safety-Labels/p6618/___ 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] grid-tie inverters & generators
In a message dated 11/20/2008 9:57:54 A.M. Pacific Standard Time, [EMAIL PROTECTED] writes: It opens when the genny is on) might be easier than a NO relay on the grid-side. Anyone do it this way? Kelly, I would do this and sleep at night. Don **One site has it all. Your email accounts, your social networks, and the things you love. Try the new AOL.com today!(http://pr.atwola.com/promoclk/10075x1212962939x1200825291/aol?redir=http://www.aol.com/?optin=new-dp %26icid=aolcom40vanity%26ncid=emlcntaolcom0001) ___ 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-wrenches] DC Rating of Disconnects
If the inverter will not backfeed currents from the grid, and if you have less than 3 strings I do not see why you would need to use fuses in the DC disco (assuming 15 amp series fuse rating). If you are at more than three strings it seems to me that the fuses in the combiner would take care of the fusing requirements. Jeff Blick PV installer Sunlight Solar Inc. 4 NW Franklin Bend, OR 97701 direct: 541-306-4196 fax: 541-322-1911 [EMAIL PROTECTED] www.sunlightsolar.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Friday, November 21, 2008 11:04 AM To: re-wrenches@lists.re-wrenches.org Subject: RE-wrenches Digest, Vol 1, Issue 349 Send RE-wrenches mailing list submissions to re-wrenches@lists.re-wrenches.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org or, via email, send a message with subject or body 'help' to [EMAIL PROTECTED] You can reach the person managing the list at [EMAIL PROTECTED] When replying, please edit your Subject line so it is more specific than "Re: Contents of RE-wrenches digest..." When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message. Today's Topics: 1. Re: DC Rating of Disconnects (ASAP POWER! 2) -- Message: 1 Date: Fri, 21 Nov 2008 10:47:12 -0800 From: "ASAP POWER! 2" <[EMAIL PROTECTED]> Subject: Re: [RE-wrenches] DC Rating of Disconnects To: "'RE-wrenches'" Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii" In 2008, we have had to replace our standard Sq. D HU361RB used since our beginnings, with the Sq. D H361RB (U stands for unfused). Was there some sort of code change NEC or CBC maybe that made most jurisdictions in So Cal suddenly start requiring fused DC disconnects? Typically, we fill the fused Sq. D. box with 15A 5" fuses. Peter D. _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Miller Sent: Friday, November 21, 2008 9:43 AM To: RE-wrenches Subject: Re: [RE-wrenches] DC Rating of Disconnects Peter: I am resending, the first version inexplicably deleted some text: An arc is created in the process of disconnecting any current under load. DC circuits have an enhanced ability to sustain that arc. PV circuits exacerbate this problem as a short or load is disconnected because they can sustain a short but the voltage rises drastically as a circuit is disconnected. This all justifies the added expense of a DC rated disconnect. We use the Square D HU361 without hesitation. There are few alternatives available and none with any significant cost savings. In selecting a disconnect, a design-build contractor must use the highest Voc possible. Make sure you are entering the 690.7 table with the record low temperature for the location. If we used a disconnect without the correct rating we would open ourselves to unacceptable liability exposure and, worse yet, would not experience that pleasant feeling one gets when you know you've done the job right. William Miller At 09:11 AM 11/21/2008, you wrote: _ From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesnt come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. >From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President -- next part -- An HTML attachment was scrubbed... URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachme nts/20081121/5ee8b648/attachment.html> -- ___ 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-wrench
Re: [RE-wrenches] DC Rating of Disconnects
In 2008, we have had to replace our standard Sq. D HU361RB used since our beginnings, with the Sq. D H361RB (U stands for unfused). Was there some sort of code change NEC or CBC maybe that made most jurisdictions in So Cal suddenly start requiring fused DC disconnects? Typically, we fill the fused Sq. D. box with 15A 5" fuses. Peter D. _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Miller Sent: Friday, November 21, 2008 9:43 AM To: RE-wrenches Subject: Re: [RE-wrenches] DC Rating of Disconnects Peter: I am resending, the first version inexplicably deleted some text: An arc is created in the process of disconnecting any current under load. DC circuits have an enhanced ability to sustain that arc. PV circuits exacerbate this problem as a short or load is disconnected because they can sustain a short but the voltage rises drastically as a circuit is disconnected. This all justifies the added expense of a DC rated disconnect. We use the Square D HU361 without hesitation. There are few alternatives available and none with any significant cost savings. In selecting a disconnect, a design-build contractor must use the highest Voc possible. Make sure you are entering the 690.7 table with the record low temperature for the location. If we used a disconnect without the correct rating we would open ourselves to unacceptable liability exposure and, worse yet, would not experience that pleasant feeling one gets when you know you've done the job right. William Miller At 09:11 AM 11/21/2008, you wrote: _ From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesnt come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. >From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President ___ 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] DC Rating of Disconnects
Yes we have T-corrected the Voc. One of the nice things we have going for us in the LA area, is the moderating influence of the ocean. 90% + of our systems never see record cold temperatures below 14 def F. You are correct about the Vdc rising upon disconnection (from Vmp to Voc) and DC arcs being a different beast than AC arcs. It is perhaps this latter reason which so few medium duty discos have a DC rating. Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Miller Sent: Friday, November 21, 2008 9:43 AM To: RE-wrenches Subject: Re: [RE-wrenches] DC Rating of Disconnects Peter: I am resending, the first version inexplicably deleted some text: An arc is created in the process of disconnecting any current under load. DC circuits have an enhanced ability to sustain that arc. PV circuits exacerbate this problem as a short or load is disconnected because they can sustain a short but the voltage rises drastically as a circuit is disconnected. This all justifies the added expense of a DC rated disconnect. We use the Square D HU361 without hesitation. There are few alternatives available and none with any significant cost savings. In selecting a disconnect, a design-build contractor must use the highest Voc possible. Make sure you are entering the 690.7 table with the record low temperature for the location. If we used a disconnect without the correct rating we would open ourselves to unacceptable liability exposure and, worse yet, would not experience that pleasant feeling one gets when you know you've done the job right. William Miller At 09:11 AM 11/21/2008, you wrote: Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] _ From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesnt come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. >From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President ___ 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] DC Rating of Disconnects
Peter: I am resending, the first version inexplicably deleted some text: An arc is created in the process of disconnecting any current under load. DC circuits have an enhanced ability to sustain that arc. PV circuits exacerbate this problem as a short or load is disconnected because they can sustain a short but the voltage rises drastically as a circuit is disconnected. This all justifies the added expense of a DC rated disconnect. We use the Square D HU361 without hesitation. There are few alternatives available and none with any significant cost savings. In selecting a disconnect, a design-build contractor must use the highest Voc possible. Make sure you are entering the 690.7 table with the record low temperature for the location. If we used a disconnect without the correct rating we would open ourselves to unacceptable liability exposure and, worse yet, would not experience that pleasant feeling one gets when you know you've done the job right. William Miller At 09:11 AM 11/21/2008, you wrote: Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] -- From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesn't come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President ___ 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] DC Rating of Disconnects
Peter: An arc is created in the process of disconnecting any current under load. DC circuits have an enhanced ability to sustain that arc. PV circuits exacerbate this problem as a short or load is disconnected because they can sustain a short but the voltage rises drastically as a circuit is disconnected. This all justifies the added expense of a DC rated disconnect. We use the Square D HU361 without hesitation. There are few alternatives available and none with any significant cost savings. In selecting a disconnect, a design-build contractor must use the highest Voc possible. Make sure you are entering the If we used a disconnect without the correct rating we would open ourselves to unacceptable liability exposure and, worse yet, would not experience that pleasant feeling one gets when you know you've done the job right. William Miller At 09:11 AM 11/21/2008, you wrote: Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] -- From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesn't come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President ___ 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] DC Rating of Disconnects
Peter, Many general duty safety switches, such as the Siemens GNF321R, are rated for 250 volts dc. They usually require the use of two switch poles. Kent Osterberg Blue Mountain Solar Peter Parrish wrote: Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] *From:* Peter Parrish [mailto:[EMAIL PROTECTED] *Sent:* Friday, November 21, 2008 9:10 AM *To:* 'RE-wrenches' *Cc:* 'Peter Parrish' *Subject:* DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesn’t come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] ___ 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] DC Rating of Disconnects
Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] _ From: Peter Parrish [mailto:[EMAIL PROTECTED] Sent: Friday, November 21, 2008 9:10 AM To: 'RE-wrenches' Cc: 'Peter Parrish' Subject: DC Rating of Disconnects I am looking into using the PV Powered PVP2000 inverter for some small, low voltage designs. The string Voc will be around 200 Vdc, worst case. Since the PVP2000 doesn't come with a DC disconnect, I am wondered what other wrenches who install the PVP2000 have been doing about this. I hate to spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the means of disconnection. I believe that the 240 V AC discos such as the SD DU221RB have no DC rating. >From an academic point of view, I wonder why the smaller discos are not dual rated, since we all know that the real-time voltage difference in a 240 V AC system can be 41% greater than 240 V. In any event, any Code-compliant solutions would be greatly appreciated. - Peter Peter T. Parrish, President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] ___ 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] box fill calcs
I believe you would just determine the size of the J-Box based on the largest sized conduit entering and leaving the box. Code: 314.28 A 1&2 Carl Hansen___ 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] box fill calcs
At 05:40 AM 11/21/2008, you wrote: I brought this subject up in class. Chuck says he doesn't think there's anything in the code about it. the closest thing I could come up with was clamps -- so you'd relate it to the largest conductor in the box. But I'm a baby too. i like over sized boxes. db The Code doesn't cover every possible aspect. The size of the splicing devices does not seem to be covered. You could have a minimum sized junction box, and connect the wires with big blue wire nuts and have trouble getting it all in. I'm also a believer in oversized boxes. The code minimum size box is the smallest box that everything can be stuffed into. Labor saved will usually be more than money spent on a bit more comfortable fit. Drake Chamberlin Athens Electric OH License 44810 CO License 3773 740-448-7328 740-856-9648 ___ 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] box fill calcs
I brought this subject up in class. Chuck says he doesn't think there's anything in the code about it. the closest thing I could come up with was clamps -- so you'd relate it to the largest conductor in the box. But I'm a baby too. i like over sized boxes. db Dan Brown President Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.com NABCEP #092907-44 ** One site has it all. Your email accounts, your social networks, and the things you love. Try the new AOL.com today!(http://pr.atwola.com/promoclk/10075x1212962939x1200825291/aol?redir=http://www.aol. com/?optin=new-dp%26icid=aolcom40vanity%26ncid=emlcntaolcom0001) ___ 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] Shoes
The Amish builders in our area swear by "Faded Glory" from Walmart. Cheap in price and best for traction, especially on steel roofs. Mark Original Message Subject: [RE-wrenches] ShoesFrom: "Mark Frye" <[EMAIL PROTECTED]>Date: Thu, November 20, 2008 4:29 pmTo: "'RE-wrenches'" Any thoughts on the best type of shoe for working on comp shingle roof? Good traction, least wear and tear on shingles? Has anyone tried a felt soled fishing boot? Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com ___List sponsored by Home Power magazineList Address: RE-wrenches@lists.re-wrenches.orgOptions & settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.orgList-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.orgList rules & etiquette:www.re-wrenches.org/etiquette.htmCheck 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
Re: [RE-wrenches] grid-tie inverters & generators
How close is the transfer panel from the main panel? If the distance is not to far then actuate the relay (nc) from the generator source NOT the utility. Generator running the relay is opened, only need to switch one leg of the SMA stuff as the reduced input voltage would keep it from connecting. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kelly Keilwitz, Whidbey Sun & Wind Sent: Thursday, November 20, 2008 12:31 PM To: RE Wrenches listserve Subject: Re: [RE-wrenches] grid-tie inverters & generators Jay, Drake, Don, Jeff & Wrenches, The relay seems like a reasonable solution. However, if the main panel is entirely backed up by the genny, to power the relay from the grid (only) requires a line-side tap, yes? Is there a simple solution that I¹m missing? We have another, similar system completed, just waiting for 2009 to commission. So, I'd like to know if it's really needed, and the best procedure, before investing the time and cost to go back. There must be many Wrenches who have encountered such generator backup systems. Come on, how many of you, besides Don, have connected the inverter to the gen-tran main panel (with no disconnection relay) without a problem? Anyone else had a bad experience, like Jeff? Thanks, -Kelly Kelly Keilwitz, P.E. Whidbey Sun & Wind, LLC Renewable Energy Systems NABCEP Certified PV Installer 987 Wanamaker Rd, Coupeville, WA 98239 PH & FAX 360-678-7131 [EMAIL PROTECTED] On 11/19/08 9:21 PM, "Jay Peltz" <[EMAIL PROTECTED]> wrote: > Hi Kelly > > I think what happens if the inverter backfeeds the genny, the > generator voltage will go up, if it goes up enough, it will go outside > the window of the inverter and the inverter will drop out, voltage > will them return to normal, inverter will reconnect and repeat. > > But I sure wouldn't want to fix the generator. A relay powered from > the grid will take care of the problem. > > jay > > peltz power ___ > On 11/19/08 8:52 PM, "Drake Chamberlin" <[EMAIL PROTECTED]> wrote: > It is recommended to use a relay to disconnect the inverter when the > panel is being fed by the generator. ___ On 11/19/08 7:28 PM, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: >That is the way I see it. I have tested systems with gens and had no >issues. The Sunny Boy would not boot to a gen source. However, you can >understand what the official position must be. There exist gensets with >accuracy or it might just happen by chance. Low probability, but not >zero. > > Don Loweburg ___ On 11/19/08 9:42 PM, "Jeff Clearwater, Village Power Design" <[EMAIL PROTECTED]> wrote: > > We burnt up a gen set's voltage regulator on an off-grid system sunny > island/sunny boy system when we took the sunny island's off-line but > didn't shut off the sunny boy. So the SB backfed the genny and fried > the very expensive voltage regulator on a 30 KW system. SMA had us > install a relay to tell the SB to shut down as soon as the AC > reference from the SI was gone. Same situation as grid-tie really in > terms of your question. > > Jeff ___ 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
