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 Post subject: Xantrex: STXR Problem - Thermal Derating
PostPosted: Tue May 30, 2006 2:24 pm GMT EthGMT 
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Minnow
Minnow

Joined: Sat Sep 07, 2002 1:01 am GMT EthGMT
Posts: 11
Location: San Juan Capistrano, CA
My wonderful STXR2500 is having it's problems today. The weather in Southern California today is great, it's late morning, seventy degrees and the inverter is in the shade. Power production has been down for the last few days so I was keeping an eye on the inverter/datalogger. When the power dropped off to about 250 watts, I checked the sky, no clouds. So I looked at the inverter display and it's indicating "Thermal Derating" and cycling through a 256 watt and 1024 watt max condition.

So, my question is: is there anything I can do? Check the fan, clean the heat sink? I am a hands-on kind of EE so I don't mind getting my hands dirty. Anything but the dreaded RMA and return to the factory.

Thanks,

Tom


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 Post subject:
PostPosted: Tue May 30, 2006 3:27 pm GMT EthGMT 
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Catfish
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Joined: Sun Sep 11, 2005 2:31 pm GMT EthGMT
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Location: Ontario Canada
All of the above sound like places to start. The fan on my ST runs at anything above 100 watts so if your is the same do you hear it running?
If you are out of warranty there is no RMA on those old models. If you are lucky enough to be in the warranty period Xante will offer a sweet deal on a new GT. :wink:


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 Post subject:
PostPosted: Tue May 30, 2006 4:11 pm GMT EthGMT 
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Red Cobra Delta Guppy
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Since the unit is displaying thermal derating, you must have a UPG unit.

This would indicate the unit thinks the heatsink is over tempature, so check that the airflow is clear and the fan is working, beyond that, you have to send it in for service

The old ST/XR are totally different, they turn the fan on regardless at 100 watts (full blast) and don't have derating code, just over temp shutdown

I had one of my develpoment units do this after a lighting storm, a strike took out the CPU card, so if the heatsink isn't hot and or fan is working, its probably something that can't be field repaired

I know they built 500 units ( main boards ) for feild repair stock, so you should be able to have a warrenty unit repaired


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 Post subject:
PostPosted: Tue May 30, 2006 6:54 pm GMT EthGMT 
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Minnow
Minnow

Joined: Sat Sep 07, 2002 1:01 am GMT EthGMT
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Location: San Juan Capistrano, CA
The STXR2500 has been so much quieter since the upgrade that I had not noticed that the fan was not running. The unit is hot, the fan spins freely, but it just is not spinning. I assume it's a control or drive circuit. So, it's back to the factory.

I posted on this board after registering a support request with Xantrex. And, after giving up on fifteen minutes of music-on-hold. They automatically sent me a case number. But here I already have two responses. This is a great board. Xantrex support, on the other hand, is not very responsive.


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 Post subject:
PostPosted: Tue May 30, 2006 7:09 pm GMT EthGMT 
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Minnow
Minnow

Joined: Sat Sep 07, 2002 1:01 am GMT EthGMT
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Location: San Juan Capistrano, CA
Other things I forgot to mention: The unit is under warranty for six more months. About two years it went down totally and was given a new main board. And, it has another issue:

In the morning, after sun rise but before sun is directly on the panels, the unit hums and my data logger indicates negative power. For a few hours on most mornings it's humming and consuming power, sometimes a couple hundred watts. But this does not happen every day.

I talked to Xantrex support about this problem but it was new to them and they had no clue about what to do. My wild guess is that a leakage path has developed, maybe a FET in the output. I'm not sure that issue will be resolved if it goes back for the fan problem. I'll certainly document the issue but, I'm worried, it might not get fixed.


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 Post subject:
PostPosted: Tue May 30, 2006 7:13 pm GMT EthGMT 
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Red Cobra Delta Guppy
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Sounds like your unit is verifying my over temp code :?

There is not much to that circuit, turn off the breakers, wait a few minutes, then pull off the front cover and make sure that the fan connectors are plugged into the main board , also give a tug on the two wires, my guess is its either a bad crip on one of the wires or it's not firmly plugged into the main board

also make sure the CPU cable is firmly in place into the main board, if that is lose it could cause what your seeing

When you first turn on the breakers, the fan will come on for a second or two ( this is from memory, as I no longer have any Sunties)


Last edited by Solar Guppy on Tue May 30, 2006 7:31 pm GMT EthGMT, edited 1 time in total.

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 Post subject:
PostPosted: Tue May 30, 2006 7:15 pm GMT EthGMT 
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Red Cobra Delta Guppy
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ON the hum, thats NOT good, sound like its not properly calabrated, send it back for this reason alone ( just say it goes into over temp ) and request the main board be swapped


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 Post subject:
PostPosted: Wed May 31, 2006 6:05 pm GMT EstGMT 
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Minnow
Minnow

Joined: Sat Sep 07, 2002 1:01 am GMT EthGMT
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Location: San Juan Capistrano, CA
I checked the fan cable connection to the main board. It’s a latching connector and was not loose. Removing and replacing it several times should have “cleanedâ€￾ the contacts.

The ribbon cable between the main board and the controller had the extractor levers glued in place. But, that didn't stop me from giving them a good wiggle. Again trying to improve the contact.

None of that has helped. The fan is still not spinning-up. Since I put it back together it’s putting out about 1500 watts and not doing the Thermal Derating thing. But, the fan is not spinning. Today the weather is fine but a little cooler that yesterday.

After about fifteen minutes it did start the derating again. I will attach a power monitor view.


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Thermal Detratng1.JPG
Thermal Detratng1.JPG [ 21.79 KiB | Viewed 2525 times ]
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 Post subject:
PostPosted: Wed May 31, 2006 7:09 pm GMT EstGMT 
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Red Cobra Delta Guppy
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Send it back for repair, it needs the main board replaced, possibly also the fan

The reverse power flow at low power is very bad, indicating the main board is out of calabration, the fan not working could be fan, main board or cpu card

Feel free to print this out for the techs


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 Post subject: Suntie Fan Blues
PostPosted: Thu Jun 15, 2006 1:39 am GMT EthGMT 
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Fish Eggs
Fish Eggs

Joined: Tue Mar 28, 2006 1:55 am GMT EthGMT
Posts: 5
Location: Redding Ca
I sympathize with your fan issue as I just went through something similar. My Suntie was off warrantee 5 months ago and I went to the garage where my unit is mounted and at 9:30 pm 2 hours after dark I could hear my Suntie Growling, never hearing this before I removed the cover and the fan was quite hot and spinning very slowly. I contacted Xantrex and waited through 45 minutes of muzak and finally got someone who told me they're resident expert on these units wasn't in but maybe the fan is bad. Being an Power systems tech myself I told him well the Drive circuit for the fan must be bad. Well he tried to say its the fan if you want more call tomarrow.
Well I called the next day and got another tech after the long wait.
He talked to me and seemed like he wanted to help. He then gave me a different phone number for a bench tech who works on Sunties but told me
" Don't tell him who gave you this number cause He'll kill me." I promised I wouldn't and called this gentleman. I explained my problem and he responded I need to send it in and couldn't give me a price, and "Who gave you this number" he asked. I responded, a gentleman who cares about customer service, he did offer the $999.00 price on the new unit however I think Xantrex made a mistake following all the other inverter companies with string inverters. My system has areas which shading occurs and in a large series string kiss that power goodbye if one panel gets shaded in the string. Too bad they now swim with the other fish. After removing the main board and tracing the fan control circuit, Its just a triac coupled by an optocoupler to the CPU somewhere. I fixed my inverter with a 1 uf cap in series with the fan, controlled by a relay whose coil is energized by my array or "the input." It works great now. I cannot recommend this type of thing to others however it is frustrating that the inverter itself is already failing and it hasn't paid for itself yet. And on top of that its just the fan control circuit, not the inverter.


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 Post subject:
PostPosted: Thu Jun 15, 2006 9:54 am GMT EthGMT 
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Red Cobra Delta Guppy
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The Triac is a Q6004L4 ...

http://www.teccor.com/cgi-bin/r.cgi/en/ ... HuuuOmFXvg

I looked at the specs and think this part will work as a replacement

http://www.digikey.com/scripts/DkSearch ... 60&Site=US

Its instock at Digikey for 1.40

I have to save your VERY brave to be pulling out the the main power board!

As for strings arrays and configurations, your incorrect in your thinking, in a single series string, the loss of a panel to shading only lowers the total available voltage, as the bypass diode kicks in. As long as the total vmp voltage is above the inverters minimum, full available power is still harvested from the remaining unshaded panels


Now if you have TWO or more series strings, and you shade a single panel in only one of the strings, you now have mismatched series strings and the losses will be more than a single panel ... so you should wire the panels panels so the shading is common to the parralell strings in this case

The only plus for 48V nominal strings (Suntie) is you can have a system with as little as 2 24V panels, otherwise in everyway the GT is a better product and to get one for 999 is a steal, you should be thankful Xantrex is willing to offer this deal for an out-of-warranty unit


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 Post subject:
PostPosted: Fri Jun 16, 2006 1:37 am GMT EthGMT 
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Fish Eggs
Fish Eggs

Joined: Tue Mar 28, 2006 1:55 am GMT EthGMT
Posts: 5
Location: Redding Ca
Ya know I thought about the Triac being bad but I just am not an expert on those, Fet's, Bipolar (ancient history), power stuff I am good at. Xantrex led me to believe the problem was upstream from that. Leaky Triac ? Wasn't sure bout those but hey its just another semiconductor, I will try that and if it works I can rip the bandaids off. I have an old ST2500 I got cheap from a friend and I spent a little time studying it, doing a block diagram and replacing blown caps and it works but still thinks the voltage is above 264 from time to time, I don't know if this is typical for the old units but a couple of guys at Xantrex did give me thermister part numbers and help me a bit getting it this far. (It was wierd, it was like they were going out on a limb to help me. The employees seem great but xantrex policies seem hard on people who want to help). I meant it that unit as a spare. The UPG is great when it is workin. I did consider Xantrex's offer but I also have an Outback unit which is meant for another string, but it handled everything fine. The loss in batteries is considerable. Anyway When I get back from my trip to the seattle area I'll tell you more, I really appreciate the correspondance...If I have time I am going to stop by Outback and Midnight Solar and say Hi. Thanks


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 Post subject:
PostPosted: Fri Jun 16, 2006 8:01 am GMT EthGMT 
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Red Cobra Delta Guppy
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Quote:
The UPG is great when it is workin


You have found a case where it isn't?, I have had NO reports of functional issues with the UPG's


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 Post subject:
PostPosted: Wed Jun 21, 2006 12:36 pm GMT EstGMT 
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Minnow
Minnow

Joined: Sat Sep 07, 2002 1:01 am GMT EthGMT
Posts: 11
Location: San Juan Capistrano, CA
My STXR2500 is back from Xantrex. I shipped it on June second and it returned on the twentieth. Considering that it spent about eight days in shipping each way, that's very good turn around. Still for me, that's twenty days with zero production. The packing list noted:

REPLACED MAIN BOARD AND SENSOR BOARD.
REPLACED FAN.
FULL TEST, NO OTHER PROBLEM.

I wired it back in last night and it came up this morning with no issues. The fan is working and it's putting out good power for this time of day. I'll need to watch it this afternoon, when it's hotter, to confirm the derating problem has been fixed. But, so far, so good.


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 Post subject:
PostPosted: Wed Jun 21, 2006 9:22 pm GMT EstGMT 
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Red Cobra Delta Guppy
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Sounds like you will be good to go for a very long time with everything replaced, I'm pleased to hear you can still get UPG's repaired :D

If you have time, please upload some pictures of your setup


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