Peter and all, LADWP used to do a more comprehensive test. Off the record, an inverter did fail that test because the manufacturer violated their listing (AEI--no longer in business). To this person's knowledge may be correct. The problem was addressed properly, but we don't want to get on our high haunches and make blanket statements because we want them to be true.
The primary justification for removing the disconnect requirement for residential is that the utility already has an isolation point with their serving meter (called a self-contained meter). This is unique to smaller services of 200-amps or less. Although we would like the requirement to be removed in general, removing the requirement would actually require redefining PV inverters as non-sources. The National Electrical Safety Code (NESC) requires an isolation device with a visible break for all sources of electricity--we have to get an exception to that or the utility would be in violation of their code that they are legally required to uphold. By requesting that utilities remove the requirement for customers served by self-contained meters, the utility meets their obligations, and we get what we want. Solving this for larger systems will require an NESC change. Bill. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Peter Parrish Sent: Sunday, October 05, 2008 9:50 AM To: [EMAIL PROTECTED]; 'RE-wrenches' Subject: Re: [RE-wrenches] Utility Dis-connect Wrenches who toil in LADWP-land. Why can't we bring our collective intellect and force to bear on this redundant, unnecessary and costly requirement? I believe that the Los Angeles Department of Water and Power Solar Incentive office has at least five years of data on anti-islanding: every PV system that applies for a rebate at LADWP undergoes an anti-islanding test. I can describe the test for anyone who wants to know the details, but in summary the inverter is verified to turn OFF when the grid is disconnected (but a load is still provided to the inverter) and verified to turn back ON after 300 secs when the grid is re-connected. I spoke to a field engineer back in 2006 and he commented that not a single inverter ever failed this test to his knowledge. Could this data set be used to support the removal of this requirement? What would be the venue to engage the Department on this? - 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] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Glenn Burt Sent: Saturday, October 04, 2008 3:25 PM To: [EMAIL PROTECTED]; 'RE-wrenches' Subject: Re: [RE-wrenches] Utility Dis-connect Here in NY, the State Public Service Commission is proposing the lockable AC disconnect requirement be removed for systems below 15kW. This from a recently circulated New York State Standard Interconnection Requirements proposal: 4. The use of external disconnect switch has proven to be redundant and unnecessary in small residential systems using inverters that meet relevant Underwriters Laboratories (UL) and Institute of Electrical and Electronics Engineers (IEEE) standards. Therefore, Staff proposes to eliminate the external disconnect switch requirements for systems 15 kW or less that meet UL 1741 (November 2005 revision). There may be hope yet! -Glenn Burt -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Yago Sent: Saturday, October 04, 2008 9:25 AM To: RE-wrenches Subject: Re: [RE-wrenches] Utility Dis-connect I know installing the totally useless exterior lock-able dis-connect has been a bone of contention for us all, but was a necessary evil to get many utilities to sign onto net metering in their state back in the late 90's. However, now that we have had a few years of showing these are never used, are not needed, linemen would not know if there were in their work area, and are a waste of money, has there been any states or utilities that are giving up on this requirement? If not, any interest in trying to make this requirement go away? Jeff Yago _____________________________________________________________ Netscape. Just the Net You Need. _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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: [email protected] 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: [email protected] 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: [email protected] 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
