Burnt Inverter

System · September 2008

Hello to everyone on this forum. I recently returned from Sierra Leone, in West Africa, my original Country of origin where I participated in the installation and start-up of a 2.1KW off-grid solar system at my Alma Mater, the Prince of Wales School. Sierra Leone uses 220V/50hz. You can get details of this project below. I have worked tirelessly on this project from concept through installation and start-up for more than two years. Unfortunately, less than a month after I returned, I was informed that the Outback Inverter burnt down. I am still awaiting the detailed Report but the preliminary finding is that the Inverter burnt down because three 110V Belkin Surgemaster Surger Protectors that we shipped from the USA for use for connecting the Laptops at the Computer Center were "fried" and caused the inverter to burn up. I am not an electrical engineer ( I am a Civil/Environmental Engineer that got into solar because on my interest in renewable energy). I do not want to believe this story and I am looking for an independent feedback before deciding whether there is a Warranty issue here from either the Manufacturer of the Outback Inverter or the Solar Installation contractor. They were supposed to issue a lightening arrestor on the roof of the building and they did not at the time I left Sierra Leone and only recently installed it (after the inverter failure). They indicated that the following parts were burnt on the Outback Inverter.

FET Power Board FX2024E and Sine Wave Processor Board [CPU] FX2024E

The Outback Solar Inverter we bought (in the USA) and installed is FX2024ET and is a 220V/50hz unit.

Links to project

http://www.youtube.com/watch?v=Nc19lMxIGkI

http://photobucket.com/powsolarproject

http://www.worldpress.org/Africa/3180.cfm

Thanks for any feedback.

Sam

Folks. I just got the Report on the burnt Inverter and I have pasted it below. My firsttake is that indeed four 110 Surge Protectors failing may have indeed led to the failure. Let me know you opinions and if you think this may be covered under Warranty.
REPORT ON THE FAILURE OF THE 2.0KW SOLAR SYSTEM AT THE PRINCE OF WALES SCHOOL.

On or about the 31st July 2008, I was informed that the Solar System at the school has failed to operate. I made a visit to the school to inspect the system and discovered that:
1.The charging part of the system was operating properly and that the Battery Bank was fully charged.
2.The intermediate circuitry was operating efficiently and is delivering power to the Inverter for processing.
3.The Inverter output was completely dead though there was power at its input port.

In order to find the cause of the failure problem, the inverter was removed and opened up. The smell of burnt components immediately occupied the atmosphere in the room. On further inspection, it was found out that the OUTPUT circuitry supplying 230Vac was damaged. A problem of this nature could only be attributed to an overload of the output circuit of the Inverter.

A couple of days earlier, at the time when “Access Point” the company which installed the Lap-tops and got the IT facility up and running were on the job, I was informed that the system had a problem, was not operating properly and was blowing the fuses in the system. This was surprising.

I went over to find out what was actually the problem. I was informed that the inverter system was blowing up fuses in the power extension unit used for distributing power to several units from one power point or outlet.

Upon investigation, inspection and test carried out, I discovered that the Extension unit has a protective circuit for surge rated at 110Vac. This Extension unit therefore cannot withstand a voltage supply of 230Vac which is more than twice its rated voltage. In all, three units of the extension cables were used in the process of Installation and all the fuses blown.

The power stress caused during the trials of these Extension units on the Inverter have seriously affected its output circuit and thereby bringing some level of deterioration in its performance and efficiency. This therefore has led to the present circumstance in which the output circuit of the Inverter has collapsed and failed to deliver power.

The output circuit will have to be replaced for the system to be functional again.
Considering the total number of Laptop units and other accessories using power such as printers and lights, we want to suggest that the system Inverter be upgraded to a 3.0Kwatts unit.

This will reduce power stress on the Solar System

mike95490 · September 2008

Re: Burnt Inverter

Now, how to package this lesson so the students at the school can learn from it.

niel · September 2008

Re: Burnt Inverter

wrong components can be a real *$%^& and detrimental to a system as you had found out. those components created a short to the output of the inverter and thus the damage. some protectors are movs and they can explode causing damages if not injuries. i'm not sure if the fuses where between the inverter and the surge protectors, but this certainly would help to protect the inverter from such a circumstance, depending on the fuse rating used as high values can pass huge surges before the fuse pops, and is no guarantee that the huge surge couldn't damage the output transistors before such fuses blow. if repeatedly replacing the fuses and they blow, this stresses the transistors too and causes failures at times.

JESSICA · September 2008

Re: Burnt Inverter

:grrSince I am a victim myself of the "burnt inverter" epidemics (see the discussion of my problem at
http://forum.solar-electric.com/showthread.php?t=3501 ), I have to ask: Aren't these expensive artifacts suppossedly protected against malfuction and all sort of melt-downs?
All major brands of inverters (EXELTECH, OUTBACK, XANTREX, etc.) advertise their products as OVER-LOAD, UNDER-LOAD, EXTRATERRESTRIAL-LOAD protected, but then you plug a simple power strip to one of them and they blow up. They are supposed to have fuses, diodes, and all kind of internal gizmos to protect them, but they just don't work. And worst of all, when the super-duper inverter fails...well...it was not it's fault! Either the strips, or the surge suppressor, or the tv, or the hair blower, or a sudden cloud are to blame.
This is just not right; and we all, and the sponsor of this forum, itself a major vendor of inverters, should do something to demmand more quality and reliability from this people.

mike95490 · September 2008

Re: Burnt Inverter

This case, where 120V devices, were plugged into a 220V inverter, and the inverter repeatedly blew fuses, which were replaced several times, before the inverter cooked, is to me, a case of abuse.

Solar Guppy · September 2008

Re: Burnt Inverter

No inverter can handle dead shorts on the output, which is what was reportedly happened here.

plugging in a 120V "surge protector" did its job, the 230V "surge" was clamped ( by MOV's ) which are a one-time device which short out to protect the load NOT the source

Nothing is at fault with ANY of the devices listed here, its the users that cooked the inverter.

It would also appear the inverter did not have the required circuit breaker on the output which is a requirement for fault protection. The fuses were in the power strips, not the inverter

boB · September 2008

Re: Burnt Inverter

Solar Guppy wrote: »

No inverter can handle dead shorts on the output, which is what was reportedly happened here.

Was it a short, or was it plugged into 240 volts, or was it lightning ?? Which one is it ??

Shorted outputs are one of the most easiest things to protect an inverter from. It's all that in-between stuff that's harder to protect against.... Direct lightning strikes being the most difficult, or I should probably say 99.9% impossible to prepare for.

boB

BB. · September 2008

Re: Burnt Inverter

220 VAC 50 Hz inverters and the users plugged in 120 VAC power strips to power their laptop computers (presumably with world wide capable power supplies). Presumably, the MOV clamps on the power strips popped the breakers/fuses on the power strips and somewhere along the line popped the inverter.

There also was talk about lightning arresters--but no discussions about lightning hits.

I would agree that the inverter should be well protected against shorts and would not be happy to hear than my inverter failed with these loads (lightning induced failures--that is a different matter).

-Bill

niel · September 2008

Re: Burnt Inverter

boB,
read the 2nd half of what samuel had written. it is lengthy, but clearly states it was outputting the 220vac 50hz into 110vac mov type surge protectors and blew fuses. quoted here indicates the system may have worked before these surge protectors were put in,
"A couple of days earlier, at the time when “Access Point” the company which installed the Lap-tops and got the IT facility up and running were on the job, I was informed that the system had a problem, was not operating properly and was blowing the fuses in the system."

samuel,
you could clarify some of this for us, but the company that put those 110vac surge protectors in are responcible for the inverter failure imho. also please clarify what fuses were used where and which ones blew. the big question i'm adding here is do you have the output of the inverter straight into a fuse or circuit breaker and what is its value if you did?

mike95490 · September 2008

Re: Burnt Inverter

most surge strips have breakers, not fuses.

boB · September 2008

Re: Burnt Inverter

niel wrote: »

boB,
it is lengthy, but clearly states it was outputting the 220vac 50hz into 110vac mov type surge protectors and blew fuses.

All that ~should~ normally happen, is to just blow up the MOVs. Even if they short on the inverter side of the breaker or fuse, the inverter should have protected itself. There may be more to this of course that we aren't aware of. A second side to the story as it were.

That being said, this is power electronics and power electronics can make smoke and slag sometimes. There will always be some failures. Just can't get away from that. That'd sure be nice though.

boB

JESSICA · September 2008

Re: Burnt Inverter

boB wrote: »

All that ~should~ normally happen, is to just blow up the MOVs. Even if they short on the inverter side of the breaker or fuse, the inverter should have protected itself. There may be more to this of course that we aren't aware of. A second side to the story as it were.

That being said, this is power electronics and power electronics can make smoke and slag sometimes. There will always be some failures. Just can't get away from that. That'd sure be nice though.

boB

boB:

I agree: The unit should have protected itself. That's one of the reasons they are so expensive. Now, when they do not protect themselves as they should, who is to blame?

Maybe, as mike says, this a case of abuse, maybe. But in my case there was no abuse at all, and the inverter blew up anyway. If you bought an inverter, and you paid good money for it, you have the right to expect, at least, that it's protective features work as well as the manufacturer advertises.

boB · September 2008

Re: Burnt Inverter

I agree...

JESSICA wrote: »

boB:
If you bought an inverter, and you paid good money for it, you have the right to expect, at least, that it's protective features work as well as the manufacturer advertises.

Yes, "normally". Just not 100.0 % of the time, unfortunately.

boB

System2 · September 2008

Re: Burnt Inverter

niel wrote: »

boB,
samuel,
you could clarify some of this for us, but the company that put those 110vac surge protectors in are responcible for the inverter failure imho. also please clarify what fuses were used where and which ones blew. the big question i'm adding here is do you have the output of the inverter straight into a fuse or circuit breaker and what is its value if you did?

Sorry if I am a bit long winded on my reply. I was in Sierra Leone when we commissioned the New Solar powered computer Laboratory. Unfortunately, the Ship that had our Laptops including the 110 V Surge Suppressors (I thought they were just extension cords) did not arrive in time. Therefore we loaned 20 laptops to commission the facility and I bought some local extension cords (I assume these may be 230V surge suppressors) to connect all the laptops. The solar system worked fine and all laptops were powered during the commissioning ceremony shown in the video on Youtube.

Access Point is our contractor that installed thw High Speed Internet wireless network and we asked them (a favor) to set up the Laptops when the Ship finally arrived in Sierra leone and our Laptops are delivered. They had no responsibility for knowing whether they could use the 110V Surge Suppressors or not since it was assumed that this was just an extension cord to connect additional Laptops.. Actually I left instructions with the Principal of the school who was to supervise access Point's work for them to just keep the 110V Surge Suppressors since we already had enough of the local 230V suppressors (I had no idea then that there will be a problem if we used the 110V surge suppressors).

When our goods arrived, the principal just gave the entire contents to AccessPoint and after connecting the Laptops to the 230V surge suppressors, they tried to connect a couple of the 110V suppressors (innocently not knowing the ramifications) and that was when the problem started. Maybe if they had contacted our Solar Installation Contractor (that prepared the Report I copied above) after the fuse on the first supressor blew up, maybe the two boards could have been saved. However, they continued until three of the surge suppressors fuses blew before they called the solar contractor in who then prepared the report I pasted above

Based on the comments above, I will now check with our Solar Contractor to see if there was a breaker on the output side of the converter and what the value is. if there is none, then I will ask them to add one during the replacement of the two Inverter boards.

Thanks

niel · September 2008

Re: Burnt Inverter

ok, the incident was an accident, but it still does not change the fact that it blew and maybe some talking with outback is in order as boB had indicated that it should've protected itself. i can't comment beyond this and boB can speculate, but he doesn't have the inverter in front of himself to say for sure. do keep us informed on any developements.

System2 · September 2008

Re: Burnt Inverter

niel wrote: »

ok, the incident was an accident, but it still does not change the fact that it blew and maybe some talking with outback is in order as boB had indicated that it should've protected itself. i can't comment beyond this and boB can speculate, but he doesn't have the inverter in front of himself to say for sure. do keep us informed on any developements.

Thanks to all for your input. I sent an email to Outback this morning with the Report and links to our project. I received an email from Outback indicating that they will replace the damaged circuit boards under Warranty. That says something about Outback!!

Sam

niel · September 2008

Re: Burnt Inverter

good that they will replace them, but did they say what they thought went awry and did they agree it should've protected itself?

System2 · September 2008

Re: Burnt Inverter

My focus is getting these replacement boards and shipping them out to get the system back up and running. I will ask our solar installer to put some additional safeguards like a breaker on the output side of the inverter. If others have any suggestions, please feel free to post them. I will also ask that all the 110V Surge Supressors be removed from the lab. Thanks

BB. · September 2008

Re: Burnt Inverter

My two cents--In view of your particular failures:

I would get rid of all 120 and 220 volt power strips with surge suppression and just place the surge suppressors (hard wired) on one place (at most)--the output of the inverter (and, of course, still have the DC surge suppressors for lightning protection on the DC side of your panel/battery system).

If you have need for surge suppression on a specific circuit (critical server)--then look at an isolation transformer instead.

And, I would see if there are AFCI breakers (Arc-Fault Circuit Interrupters) available for your voltage/frequency. Just a guess, but the shorting MOVs may have looked like an Arc (some MOVs have an arc gap in them--from what I recall). The AFCI may shut down shorted/arcing circuits sooner than just a regular magnetic/thermal breaker.

A Ground Fault Interrupter (GFI or RCD outside of North America) may have also helped here too--but it is possible that GFI will not work in your "local" wiring (GFI's detect current flow between "Hot" and "Safety" ground--I don't know the details about overseas AC distribution systems to know that they ground reference their AC system so that GFI's will work--or if they are even available).

Either of the above devices can help make the system safer--don't know that they would really help or not in protecting against another similar fault condition.

-Bill

niel · September 2008

Re: Burnt Inverter

bill,
those are good ideas and options for samuel to try as this could limit the amount of time the short occurs and help lessen the time the transistors are stressed, which hopefully would lessen the likelyhood of a failure.:cool:

System2 · September 2008

Re: Burnt Inverter

BB:

Thanks for the recommendations. I will pass them on to our Solar installer.

Burnt Inverter

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