James J's posts

I don't think there is a way to adjust the input minimum threshold of the inverter.  An electrician or engineer might be able to, but not me.  I don't have an extra panel to swap in to the string in order to test it.  I'd love to find a replacement one, but as with most technology purchases,  the current models are old news quickly and even more quickly taken off the shelves.   My model panel BP 5175 is impossible to find now.

Yes, these are 24 volt panels, but my system is two parallel strings of 9 panels each.  So one of my strings is open because of the dead panel.  Each string is 216vdc.  If I remove the bad panel then my voltage will be below the Sunnyboy's minimum input voltage of 208vdc.

One panel is definitely dead.  I am just wondering if this shading  caused the burn out or if it just was flawed and died prematurely.    If it was the shading, I have 7 more (of 18 total) panels in the same type of situation.  If I just remove the bad panel, the voltage would be below my inverters minimum, so I need to decide between replacing the bad one (if can find a BP 5170)  and hope that the others hold, or alter the wiring of the whole system and add Enphase inverters.  THe major change and adding the mini inverters would make the whole system work more efficiently and I would get much more production, but it would be quite expensive (9-10k).

Does anyone have a spare BP 5170 (170 watt monocrystalline) panel?

I need one, or two to fix my burned out panel(s). 

I have had a 3kw grid tied system on my house for 8 years. Two parallel strings of 9 panels on either side of a dormer to a Sunnyboy inverter. The installer decided to use two strings to deal with a dormer on the center of the roof.

Recently, one string (west) has stopped producing power because of a panel with burn marks and a local technician theorizes that hard shading from a dormer has caused this failure. Has anyone heard of hard shading causing either a cell or diode to burn up and open the circuit? The only proposed fix is to rewire the whole system, including retrofitting 8 panels that have a few hours of shading with Enphase inverters for about 9 or 10 grand. Any thoughts on this burn out problem? The local technician said that the other 7 panels that have hard shading for a few hours per day will eventually burn out also.

Any thoughts would be much appreciated!

Thanks.

My PV system, (will be up an running in two weeks), has a battery bank of 4 parallel battery pairs.  I have heard that these parallel strings need to have their own fusing/breakers.  Is this true?  If so, what is the most practical way to do this, in line fuses?  Another person advises to wire each pair to a buss bar in order to parallel them.  This apparently aids in keeping the 4 pairs equally charged.  Any comments?

It's an off grid cabin.  24v, 290watts of panels, 300-400AH battery bank (tbd).

I am looking for a used 300-400 AH 24v AGM battery set.  Hopefully, in the Maine, Massachusetts areas.  I am putting together my first small PV system for a cabin and don't want to invest in new batteries until I know what I'm doing.

I have a 24v PV system and am confused about grounding the Exeltech 1100 inverter.  The AC neutral, ground and chassis are bonded in the inverter.  Can I just ground from the AC ground/neutral to the main DC buss bar in the main DC box?  Exeltech says no ground is needed on the DC side if the negative is grounded, but the AC should be grounded to the same rod as the DC.  Another thing I need to think about it is a Midnite Solar GFP breaker that I installed in the main DC panel.  Would the AC connected to DC buss bar just trip the GFP?

This inverter ground is far more confusing than I had imagined!
Help!

Since trickle chargers on an unattended battery would not be good for the long term health of the battery, I wonder if it would be wise to leave a small load on in the winter to 'work' the batteries.  Maybe a light or two? 

Are there any charge controllers that have a programmable energy 'dump' to deplete the batteries every so often when unattended?

Thanks for the suggestions so far.

Jim

I am planning on installing a small off-grid 500w PV system in my summer cottage in Maine.  My question is about batteries.  Since the building is unheated and uninsulated, and used just in the summer, what is the best way to deal with batteries?  AGM's and disconnect over the winter?  Or any type with a trickle charger? 

I've never seen the Exeltech in person, but in their manual they say it can also be AC hardwired to the strip under the rear cover.....   "Appliances / Loads may be hard wired to the rear terminal strip (shown in Appendix “C”), in addition to the loads plugged into the front outlets. The sum of the loads must not exceed the inverter output capability."    Has anyone done this? 

One other question about no load wattage.....do all of the Exeltech 1100's come pre-wired with the Low Idle Current Option?

I guess that's a good argument for buying components via a reputable, knowledgeable, and established business.  They might have some insight into production and supply.
It's tempting to shop around on the internet for the cheapest supplier, but I've always found that a cheap source is usually not a good source.

Does anyone have any experience to report with these two inverters?  I am trying to decide which is a better inverter since cost and performance seems to be relatively similar.   It would be used for an off grid cabin.  Eventually, it will be hardwired.

I have read that the Exeltech is extremely reliable, but more difficult (physically) to hardwire.  I am leaning towards the Prosine because  it's no-load draw is much lower (1.5 watts vs 20 watts).   

Any opinions on these inverters?

I have a general question about components for a very small PV system, but soon to be a 1KW system....

When I will build a cabin in August, I need a small PV system to charge cordless tools (using about 8ah per day).  The following year I'll be adding a refrigerator and microwave. Future summers maybe slightly more power needed.

Question - Should I just buy temporary 'limited' components? Or, would something like a Xantrex Prosine 1800w inverter and Outback MX-60 work for now and future?  I'd just hate to buy cheaper components that will need to be 'retired' if they are outgrown.   And yet, I wonder if these larger components would even work efficiently with such low demands for this first summer.

Sorry if this is a really basic question.

Thank you.

jim