DelightedInYahweh
Member
- Location
- Lake Charles, La
The old thread has since been closed so I started up a new one to give an update and hopefully verify my line of thinking here.
http://forums.mikeholt.com/showthread.php?t=146292
Above is the previous thread if anyone wants to get caught up on the specifics which I will not give in this update.
Up to this point I had not yet been to the home to really do any investigation of the system. But yesterday the boss calls me and says that one of the inverters has a fault message and if I could go take a look at the system. So I surveyed the inverter, got the fault code from it so I could research it online. While I was there I decided to investigate the whole system further.
Previously I had read that 300V was the operating voltages PV inverters and that if the system was not set up correctly once the arrays began to be irradiated that the voltage would drop below these parameters. So I started checking voltages on the DC side. It was about 9:00 a.m. and only about 15 of the arrays were fully irradiated the other 10 were in the shadow of a tree, but the sun was still low. My voltages on the four inverters ranged from 305-325Vdc. No help there, or so I thought.
In the system there is a standby generac gen-set with and ATS. So I remove the cover, take off the cover to the AC PV panel, trough, and disconnects. I wanted to really look in to what had been done in the installation and what was going on. At about 10:00 the inverter displays were up to about 1500w. I grabbed my meter and read the DC voltage again......275v!!!!! I thought Aha!!! But the displays were still registering so I clamped my meter on to each circuit coming in to the AC PV panel. 6.5-7 amps on every line except the faulted inverter which I had taken off line due to the fault. Now I'm really scratching my head.
By 11 the inverter displays were up to about 1900w, and I was getting around 9amps on each individual conductor 16-18 amps on each feeder conductor that left the AC PV panel and went up to the trough were it is combined with the utility and residence AC system. I had to get to class so I closed everything up.
I did research on what I had found and the Fronius inverter that I am dealing with actually has a minimum operating voltage of 230v. Well, that explains that, but I am no further along in knowing why the homeowner is still not seeing any greater benefit from the system than they are. I go back to the system this morning and of course today is cloudy!! But the inverters are still at about 900w. I went there to finish troubleshooting out the fault in inverter 4 since I discovered that the 443 code dealt with hardware/software issues. As soon as I opened the power conversion side of the inverter I could smell the distinct smell of burnt components. I started looking and sure enough at the very top of the board was a connector that had a gaping whole in it, was charred and the wires were a bit melted. Time to call tech support!
While I was on the phone giving them the information regarding the faulted inverter I spoke with them about this issue. They gave me a few leads to follow regarding customer usage and utility metering. At this point everything is leading me more and more to the utility meter. But this was discussed in the last post. I called the utility company a few years back and they said it was indeed a net meter on the residence.
I decide to check my amp draws again. Of course the sun was going in and out behind the clouds, but the inverters were fluctuating between 900w and 2500w. As I watched my clamp on amp meter around phase A of the utility side I noticed that when the sun would come out the amp reading would drop by about 8-9 amps sometimes more. I clamped on to the feeder from the AC pv panel and got around 11 amps or more. Same was taking place on phase B and C. I put my meter back on phase A. It was reading about 12 amps. I went to the AC disconnects for the inverters and shut them down. The meter rose to 26 amps and held between 26 and 35 amps.
So I close the AC disconnects and wait for the three inverters to go through the start up process. Meanwhile I am observing the meter and it is holding at no lower that 26 amps. As soon as the three inverters initiate my reading drops to around 14-16amps and fluctuates as the clouds cover the sun and then the sun is revealed again. The same thing happens on all three phases.
At this point I am thinking that all issues now point to the fact that the meter is simply not properly set up. Is there anything in all of this that you all would think differently? Anything that may have opened up with the added information I have been able to give you all? Or is it that a 25 array 4 inverter system with each inverter registering 2600-2800w on good days is only truly making a $5 a month difference in the customers utility bill???
Thanks again guys
http://forums.mikeholt.com/showthread.php?t=146292
Above is the previous thread if anyone wants to get caught up on the specifics which I will not give in this update.
Up to this point I had not yet been to the home to really do any investigation of the system. But yesterday the boss calls me and says that one of the inverters has a fault message and if I could go take a look at the system. So I surveyed the inverter, got the fault code from it so I could research it online. While I was there I decided to investigate the whole system further.
Previously I had read that 300V was the operating voltages PV inverters and that if the system was not set up correctly once the arrays began to be irradiated that the voltage would drop below these parameters. So I started checking voltages on the DC side. It was about 9:00 a.m. and only about 15 of the arrays were fully irradiated the other 10 were in the shadow of a tree, but the sun was still low. My voltages on the four inverters ranged from 305-325Vdc. No help there, or so I thought.
In the system there is a standby generac gen-set with and ATS. So I remove the cover, take off the cover to the AC PV panel, trough, and disconnects. I wanted to really look in to what had been done in the installation and what was going on. At about 10:00 the inverter displays were up to about 1500w. I grabbed my meter and read the DC voltage again......275v!!!!! I thought Aha!!! But the displays were still registering so I clamped my meter on to each circuit coming in to the AC PV panel. 6.5-7 amps on every line except the faulted inverter which I had taken off line due to the fault. Now I'm really scratching my head.
By 11 the inverter displays were up to about 1900w, and I was getting around 9amps on each individual conductor 16-18 amps on each feeder conductor that left the AC PV panel and went up to the trough were it is combined with the utility and residence AC system. I had to get to class so I closed everything up.
I did research on what I had found and the Fronius inverter that I am dealing with actually has a minimum operating voltage of 230v. Well, that explains that, but I am no further along in knowing why the homeowner is still not seeing any greater benefit from the system than they are. I go back to the system this morning and of course today is cloudy!! But the inverters are still at about 900w. I went there to finish troubleshooting out the fault in inverter 4 since I discovered that the 443 code dealt with hardware/software issues. As soon as I opened the power conversion side of the inverter I could smell the distinct smell of burnt components. I started looking and sure enough at the very top of the board was a connector that had a gaping whole in it, was charred and the wires were a bit melted. Time to call tech support!
While I was on the phone giving them the information regarding the faulted inverter I spoke with them about this issue. They gave me a few leads to follow regarding customer usage and utility metering. At this point everything is leading me more and more to the utility meter. But this was discussed in the last post. I called the utility company a few years back and they said it was indeed a net meter on the residence.
I decide to check my amp draws again. Of course the sun was going in and out behind the clouds, but the inverters were fluctuating between 900w and 2500w. As I watched my clamp on amp meter around phase A of the utility side I noticed that when the sun would come out the amp reading would drop by about 8-9 amps sometimes more. I clamped on to the feeder from the AC pv panel and got around 11 amps or more. Same was taking place on phase B and C. I put my meter back on phase A. It was reading about 12 amps. I went to the AC disconnects for the inverters and shut them down. The meter rose to 26 amps and held between 26 and 35 amps.
So I close the AC disconnects and wait for the three inverters to go through the start up process. Meanwhile I am observing the meter and it is holding at no lower that 26 amps. As soon as the three inverters initiate my reading drops to around 14-16amps and fluctuates as the clouds cover the sun and then the sun is revealed again. The same thing happens on all three phases.
At this point I am thinking that all issues now point to the fact that the meter is simply not properly set up. Is there anything in all of this that you all would think differently? Anything that may have opened up with the added information I have been able to give you all? Or is it that a 25 array 4 inverter system with each inverter registering 2600-2800w on good days is only truly making a $5 a month difference in the customers utility bill???
Thanks again guys