I found this thread via Google while looking for information about KC 120s failing in the field. After performing fine since mid-2001, 2 of my 24 KC 120s failed this spring when their output fell to one-half of normal. Kyocera told me that they would replace the 2 failed modules with brand-new KC 130s under warranty, but I was surprised when they shipped me 24 replacement modules rather than the 2 that I had requested. When I told Kyocera that I only needed 2 replacement modules, they told me that if I was to hire someone to replace all 24 modules, they would reimburse me for the expense. Since I wasn't in a position to replace all of my PV modules, I declined Kyocera's offer, but it makes me wonder if they're having reliability issues with KC 120s in the field.

yes, they had some problems with some of the kc120s and if they sent you 24 pvs it is to replace all of your kc120s as sooner or later the rest will go and kyocera is being great about it owning up to the problem and their willingness to honor warantys. accept the kc130 pvs from them to replace your kc120s.

Yes what Neil said take the extra 240 watts and enjoy

....plus you've got to remember that those kc-130's that you just installed are now derating to the lowest panels....the other kc-120's.

Well, my first arrays ( my old house ) have had failures, the owner called two week ago saying the solar system was sick and I went and checked things out, the old Sunties had died, I had them contact Xantrex and they were able to get GT2.5's for the 999.00 price, great deal of them

Today, I went and installed the GT's and then found the KC120's ( may 2001 date codes ) , probably about 30-35% of the panels have issues.

Its the interconnects failing, clear as day, brown spots on the back. I login into MY forum at the owner home and got the contact info, which has changed!

Vicki Myers
Customer Service

KYOCERA Solar, Inc.
7812 East Acoma Drive
Scottsdale, AZ 85260

Office: (800) 544-6466
Fax: (800) 523-2329

Vicki.Myers@kyocera.com
http://www.kyocerasolar.com

The owner contacted the above person, and within minutes sent a email with a claim form, which I helped fill out and we emailed it back. To Kyocera's credit, they were very prompt and willing to swap the array.

Lucky me, I get to do the swap of the 48 panels ... , I'll get paid and the home owners are happy that the system was warranted! , the cost to them will be about 2500 for a complete replacement of dual 2880 arrays after 6 years of service, thank god its ground mounted!

I have 40 KC120-1's that Kyocera is replacing. However, they do not replace with the 130's anymore, they replace with KC120-R's (refurbished KC120-1's). Has anyone experienced replacement with the refurbished modules? Is the performance as expected?

Thanks,
Dave

You are the first to report the change, but I'm not surprised. On the array I swapped out this spring, it would have been pretty easy to repair the panels. The failure was very obvious an interconnection failure and that can be corrected with a knife and soldering iron in about 10 minutes. I did try and buy the 48 panels that were returned and at that time they indicated they would be repaired by Kyocera for future warranty repairs, so I'm not surprised they now have enough stock to recycle the older panels

The Silicon Cells themselves really don't have any life limit and I'm sure Kyocera isn't going to send out panels that haven't been thoroughly checked out and have people have failures a second time

My 40 KC-120-1 modules were replaced with KC-120-R modules. For the first week and a half things were great. But slowly it seems that these modules are failing as well. The symtom is that throughout the day, as it heats up, the modules stop producing power. Then after an hour or so they start coming back up again - I guess as the modules cool down. I can remove fuses at the combiner box and see which strings are producing power, i.e., I can remove a fuse and one string will cause a 5 amp drop in power, and others have no impact on power production.

Any thoughts before I give Kyocera another call?

That sound like a major pain, but before calling Kyocera, you need to debug a bit more ( suggestion ). Failing panels should not have current goto zero, that sounds like a wiring issue as when a panel internally has an open, the bypass diodes kick in and the remainder of the string will produce SOME current, not zero.

Before the string in question fails , open all the Jboxes in that string and then when a string goes to zero current measure each panel ( gently ) and see when the circuit is open what is amiss . If I had to guess, its possible its something as simple as a connection or two that the screws in the Jbox are not tighted by the installer

If you find that is yet again another defective panel, I'd raise this back to Kyocera ... it might be possible that some refurbs worked at the factory but in all the movement have caused more intermittent open connections ... please keep us informed of what you find

Thanks - I'll continue to gather data over the next few days. BTW, yesterday I did go through every juntion box and ensure all screws were tight - they were (all screws, including the ones for the blocking diodes.

One other note - the PV volts start out around 66 or 67 in the morning and the battery volts around 53.5. Charge controllers are always in Bulk mode feeding the grid. As the day goes on, the the PV volts drop to around 57 or so by mid-afternoon and battery volts fluctuate between 52.8 and 53.5.

Charge controllers are OutBack FM60s. Inverters are two stacked SW5548s. Grid-tied with battery backup - two 48 volt banks of Surrett 5000 series batteries.

Thanks,
Dave