[RE-wrenches] UPS disturbance with SMA Inverters
Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
How about disabling one inverter at a time when the disturbances are happening? That might narrow it down to it being a single inverter. Through the process of elimination you may be able to find out if it is a single inverter or a combination of inverters that makes it do it. It might be a specific inverter or it might be a specific combination of inverters I have seen APC UPS units click but not activate, in that case it was one inverter off grid and one UPS. Somewhat irritating, I put it where I couldn't hear it to make the problem go away so to speak ! Later, Bob ellison Bob Ellison On Aug 4, 2014, at 10:29 AM, Carl Adams swingjun...@gmail.com wrote: Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
Is it possible that the inverters are raising line voltage high enough to make the UPS respond by clicking, but not high enough to have them actually trip? I'm not familiar enough with UPS control structure, but it might run a quick test (the click) when the voltage gets close to its high voltage trip off. Just a crazed monday morning idea. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 8/4/2014 8:50 AM, RE Ellison wrote: How about disabling one inverter at a time when the disturbances are happening? That might narrow it down to it being a single inverter. Through the process of elimination you may be able to find out if it is a single inverter or a combination of inverters that makes it do it. It might be a specific inverter or it might be a specific combination of inverters I have seen APC UPS units click but not activate, in that case it was one inverter off grid and one UPS. Somewhat irritating, I put it where I couldn't hear it to make the problem go away so to speak ! Later, Bob ellison Bob Ellison On Aug 4, 2014, at 10:29 AM, Carl Adams swingjun...@gmail.com wrote: Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
I wonder if the UPS is grumbling about high voltage as the inverters push back current... Glenn -Original Message- From: Carl Adams swingjun...@gmail.com Sent: 8/4/2014 10:29 To: RE-wrenches re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] UPS disturbance with SMA Inverters Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[RE-wrenches] Ct Utility test requirement?
Wrenchers, The Ct Utility company CLP requires the following as part of the verification test. Because this is a three-phase service, the witness test must also demonstrate that the inverter shuts down upon loss of each individual phase Any recommendations on how to do this test safely? Al Frishman AeonSolar (917) 699-6641 - cell (888) 460-2867 www.aeonsolar.com ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Ct Utility test requirement?
Al, I have witnessed this test in NC several times, but with medium voltage connected systems, not systems connected to a building service. A medium voltage subcontractor used a disconnect stick to open one phase at a time at the fused cutout point of delivery to the distribution network (on the high side of the transformers) . We learned to do the test early in the morning with the array divided in subsections to keep the current as low as possible at the POD because there is an arc pulled when one phase is opened. The phase current was being monitored during the test to insure that the inverters stopped exporting current to the other two phases when one phase was lost. It's been awhile, so there may be a better/safer way to do this test for MV connected systems now that I'm not aware of...would be happy to hear about it if so. If this is a PV system connected to a building service this wouldn't be the way to do this test. Cheers, Rebekah Hren On Mon, Aug 4, 2014 at 11:24 AM, Allen Frishman amfr...@aeonsolar.com wrote: Wrenchers, The Ct Utility company CLP requires the following as part of the verification test. Because this is a three-phase service, the witness test must also demonstrate that the inverter shuts down upon loss of each individual phase Any recommendations on how to do this test safely? *Al Frishman* AeonSolar *(917) 699-6641 %28917%29%20699-6641 - cell* *(888) 460-2867 %2%29%20460-2867* *www.aeonsolar.com http://www.aeonsolar.com/* ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Tel: 336.266.8800 NABCEP Certified Solar PV Installation Professional™ 091209-85 NC Licensed Electrical Contractor ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
Bob, Ray, Glenn, Thanks for the responses. We could cycle through the inverters and see if it is one, or some combinations of inverters, which is causing the problem. This results in a minimum of 6 trials. If it is a combination of inverters many more. Any feedback on the idea of monitoring the AC circuits; computer feed and combined inverter output? Seems to me this might provide a one step correlation between the event and the cause. Just not sure what equipment to suggest for this. Could be there is some other cause, unrelated to the inverters. AC unit kicking on, etc. Though they do not see any lights dimiming/brightening, or any other notable change in electrical equipment at the sight. On Mon, Aug 4, 2014 at 1:03 PM, Glenn Burt glenn.b...@glbcc.com wrote: I wonder if the UPS is grumbling about high voltage as the inverters push back current... Glenn -- From: Carl Adams swingjun...@gmail.com Sent: 8/4/2014 10:29 To: RE-wrenches re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] UPS disturbance with SMA Inverters Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
Hello Carl, The egauge may be a good monitoring unit for this application. You can monitor 12 CT's at a time, and everything is time-stamped. The egauge is actually its own server, so it can be monitored remotely or on a site computer on the same network. It can give you power factor, phase voltage, line voltage among other parameters. It does require that all of the monitored lines are relatively close spatially (or you can get more egauges). I am curious, does the clicking that they hear from the UPS indicate the UPS is taking the load momentarily, or is it something else? Good luck On Mon, Aug 4, 2014 at 3:11 PM, Carl Adams swingjun...@gmail.com wrote: Bob, Ray, Glenn, Thanks for the responses. We could cycle through the inverters and see if it is one, or some combinations of inverters, which is causing the problem. This results in a minimum of 6 trials. If it is a combination of inverters many more. Any feedback on the idea of monitoring the AC circuits; computer feed and combined inverter output? Seems to me this might provide a one step correlation between the event and the cause. Just not sure what equipment to suggest for this. Could be there is some other cause, unrelated to the inverters. AC unit kicking on, etc. Though they do not see any lights dimiming/brightening, or any other notable change in electrical equipment at the sight. On Mon, Aug 4, 2014 at 1:03 PM, Glenn Burt glenn.b...@glbcc.com wrote: I wonder if the UPS is grumbling about high voltage as the inverters push back current... Glenn -- From: Carl Adams swingjun...@gmail.com Sent: 8/4/2014 10:29 To: RE-wrenches re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] UPS disturbance with SMA Inverters Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Mac Lewis *Yo solo sé que no sé nada. -Sócrates* ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
Is it possible that the UPS issue is raised voltage, causing the UPS voltage regulator to switch settings? A large amount of solar on a circuit can raise the voltage in the system at full sun. I would rent a Fluke Energy Analyzer and leave it in place for a number of days to see how the voltage, current and power factor varies with the inverter output. On Mon, Aug 4, 2014 at 5:11 PM, Carl Adams swingjun...@gmail.com wrote: Bob, Ray, Glenn, Thanks for the responses. We could cycle through the inverters and see if it is one, or some combinations of inverters, which is causing the problem. This results in a minimum of 6 trials. If it is a combination of inverters many more. Any feedback on the idea of monitoring the AC circuits; computer feed and combined inverter output? Seems to me this might provide a one step correlation between the event and the cause. Just not sure what equipment to suggest for this. Could be there is some other cause, unrelated to the inverters. AC unit kicking on, etc. Though they do not see any lights dimiming/brightening, or any other notable change in electrical equipment at the sight. On Mon, Aug 4, 2014 at 1:03 PM, Glenn Burt glenn.b...@glbcc.com wrote: I wonder if the UPS is grumbling about high voltage as the inverters push back current... Glenn -- From: Carl Adams swingjun...@gmail.com Sent: 8/4/2014 10:29 To: RE-wrenches re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] UPS disturbance with SMA Inverters Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Chris Mason NABCEP Certified Solar PV Installer™ Solar Design Engineer Generac Generators Industrial technician www.cometsolar.com http://www.cometenergysystems.com 264.235.5670 869.662.5670 Skype: netconcepts ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UPS disturbance with SMA Inverters
It would be good to put a volt meter at the input to the UPS confirm input voltage is within range at the time there is an issue. If volts are high there is a problem between that location and as far as the transformer. A scope would help to see noise on the AC side but an old AM radio may do the same to detect noise on the line. On Aug 4, 2014 1:30 PM, Chris Mason cometenergysyst...@gmail.com wrote: Is it possible that the UPS issue is raised voltage, causing the UPS voltage regulator to switch settings? A large amount of solar on a circuit can raise the voltage in the system at full sun. I would rent a Fluke Energy Analyzer and leave it in place for a number of days to see how the voltage, current and power factor varies with the inverter output. On Mon, Aug 4, 2014 at 5:11 PM, Carl Adams swingjun...@gmail.com wrote: Bob, Ray, Glenn, Thanks for the responses. We could cycle through the inverters and see if it is one, or some combinations of inverters, which is causing the problem. This results in a minimum of 6 trials. If it is a combination of inverters many more. Any feedback on the idea of monitoring the AC circuits; computer feed and combined inverter output? Seems to me this might provide a one step correlation between the event and the cause. Just not sure what equipment to suggest for this. Could be there is some other cause, unrelated to the inverters. AC unit kicking on, etc. Though they do not see any lights dimiming/brightening, or any other notable change in electrical equipment at the sight. On Mon, Aug 4, 2014 at 1:03 PM, Glenn Burt glenn.b...@glbcc.com wrote: I wonder if the UPS is grumbling about high voltage as the inverters push back current... Glenn -- From: Carl Adams swingjun...@gmail.com Sent: 8/4/2014 10:29 To: RE-wrenches re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] UPS disturbance with SMA Inverters Hello Wrenches, I have a site which is experiencing nuisance disturbance of the computer UPS systems at the site. The site owner suspects this is due to the PV system which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance disturbance is a clicking noise in the UPS units. The disturbance is not enough to cause the UPS to engage, so it seems to be a small disturbance on the AC power. The site owner suspects the inverters are the source of this disturbance since 1) It seems to only occur when we have a good solar day. 2) If the inverters are shut down the problem goes away, and if you start up the inverters the problem exhibits again. The site was commissioned in March of 2012 and has had no problems till this issue last month. In reviewing the event log on Sunny Portal there are no inverter anomalies. SMA tech support had not run into this issue and had no ideas, they too agree the inverters are not reporting any anomalies. The problem is not persistent but rather intermittent making this harder to troubleshoot. So my questions are 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy inverters. 2) Can you recommend an AC power monitoring tool which would support frequency and voltage monitoring on the AC line. Perhaps one data set on the circuit feeding the computers and another on the inverter output circuit. For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds into the building main distribution panel. The service is 240V single phase. With Regards Carl Adams, SunRock Solar NABCEP Certified PV Installer ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Chris Mason NABCEP Certified Solar PV Installer™ Solar Design Engineer Generac Generators Industrial technician www.cometsolar.com http://www.cometenergysystems.com 264.235.5670 869.662.5670 Skype: netconcepts ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings:
Re: [RE-wrenches] Ct Utility test requirement?
If you using a AC disconnect shut off power to it install a jumper on two of the legs just testing once inverter is back on line pull the switch and see what happens. Swap jumper location and tetest, once you tesy all legs remove jumper wires. On Aug 4, 2014 7:43 AM, Rebekah Hren rebekah.h...@gmail.com wrote: Al, I have witnessed this test in NC several times, but with medium voltage connected systems, not systems connected to a building service. A medium voltage subcontractor used a disconnect stick to open one phase at a time at the fused cutout point of delivery to the distribution network (on the high side of the transformers) . We learned to do the test early in the morning with the array divided in subsections to keep the current as low as possible at the POD because there is an arc pulled when one phase is opened. The phase current was being monitored during the test to insure that the inverters stopped exporting current to the other two phases when one phase was lost. It's been awhile, so there may be a better/safer way to do this test for MV connected systems now that I'm not aware of...would be happy to hear about it if so. If this is a PV system connected to a building service this wouldn't be the way to do this test. Cheers, Rebekah Hren On Mon, Aug 4, 2014 at 11:24 AM, Allen Frishman amfr...@aeonsolar.com wrote: Wrenchers, The Ct Utility company CLP requires the following as part of the verification test. Because this is a three-phase service, the witness test must also demonstrate that the inverter shuts down upon loss of each individual phase Any recommendations on how to do this test safely? *Al Frishman* AeonSolar *(917) 699-6641 %28917%29%20699-6641 - cell* *(888) 460-2867 %2%29%20460-2867* *www.aeonsolar.com http://www.aeonsolar.com/* ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Tel: 336.266.8800 NABCEP Certified Solar PV Installation Professional™ 091209-85 NC Licensed Electrical Contractor ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Ct Utility test requirement?
If you are using a load center to aggregate the inverter outputs, swap the 3 pole breaker for three single poles. Hopefully you can demonstrate only one inverter works. If the UL listing tests and certifies for this, why do they need to do it in the field? Next they will want you to set up a full lab test suite. On Mon, Aug 4, 2014 at 8:56 PM, Jerry Shafer jerrysgarag...@gmail.com wrote: If you using a AC disconnect shut off power to it install a jumper on two of the legs just testing once inverter is back on line pull the switch and see what happens. Swap jumper location and tetest, once you tesy all legs remove jumper wires. On Aug 4, 2014 7:43 AM, Rebekah Hren rebekah.h...@gmail.com wrote: Al, I have witnessed this test in NC several times, but with medium voltage connected systems, not systems connected to a building service. A medium voltage subcontractor used a disconnect stick to open one phase at a time at the fused cutout point of delivery to the distribution network (on the high side of the transformers) . We learned to do the test early in the morning with the array divided in subsections to keep the current as low as possible at the POD because there is an arc pulled when one phase is opened. The phase current was being monitored during the test to insure that the inverters stopped exporting current to the other two phases when one phase was lost. It's been awhile, so there may be a better/safer way to do this test for MV connected systems now that I'm not aware of...would be happy to hear about it if so. If this is a PV system connected to a building service this wouldn't be the way to do this test. Cheers, Rebekah Hren On Mon, Aug 4, 2014 at 11:24 AM, Allen Frishman amfr...@aeonsolar.com wrote: Wrenchers, The Ct Utility company CLP requires the following as part of the verification test. Because this is a three-phase service, the witness test must also demonstrate that the inverter shuts down upon loss of each individual phase Any recommendations on how to do this test safely? *Al Frishman* AeonSolar *(917) 699-6641 %28917%29%20699-6641 - cell* *(888) 460-2867 %2%29%20460-2867* *www.aeonsolar.com http://www.aeonsolar.com/* ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Tel: 336.266.8800 NABCEP Certified Solar PV Installation Professional™ 091209-85 NC Licensed Electrical Contractor ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Chris Mason NABCEP Certified Solar PV Installer™ Solar Design Engineer Generac Generators Industrial technician www.cometsolar.com http://www.cometenergysystems.com 264.235.5670 869.662.5670 Skype: netconcepts ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
