Question about the Classic's input voltage.

[tecnodave]

Dgd,

I have never pushed it that far but my old stacks of Siemens SM-55 are wired switchable 35.4/70.8 volt or 35.4/105 volt so I have the option of throwing a few switches so I can swap out Classic with Trace PWM controller for servicing of if there is a controller failure. I have run the Classic with a 34 volt in and it does have trouble on equalize on 24 volt system. My main systems are now all 72 cell panels as they are easier to handle than bunches of small panels.

David

[boB]

Verdigo,

I could not see the picture you linked to.

What is your PV Voc (open circuit) voltage and your battery voltage.  VERY important.

Do you have any "partial" shading on your PV array ?  Is your PV array hot ?
These 2 things can make the MPP (Max Power Point) voltage low.

Try this sanity check, change the "mode" from SOLAR to Legacy P&O.  This will
drag the PV voltage from Voc down to battery and then it will stay close to what
it found as MPP V but will periodically walk above and below this point.  It will do this
slow enough that you can watch it do its thing.
Maybe "SOLAR" mode isn't the best for your array and Legacy will do better ?

I will see if I can find the NAWS thread.

boB


PS...  Just found this on the NAWS forum...  AND I saw the picture !

The panels are in strings of two 37 volt vmp. The Classic's display input voltage has always dropped when the current has some place to go and without selling with charged batteries will typically show around 80 volts

2320 watts of PV
464ah GC2 battery bank @ 48 volts

Not too bad actually !  Probably just some partial shading and/or a hot day or something.
If your batteries are full and noplace for power to go, then 80V Voc would give you about
64 volts MPP so you're real close to that.  I would still try Legacy P&O anyway.

Will continue reading the NAWS thread.

http://forum.solar-electric.com/showthread.php?24707-Questions-on-over-paneling-with-Grid-Interactive-Inverter

[tecnodave]

boB,

Memory failure.....does not say that on my Classic. CL11137..... It's in the online manual  dated 1/7/13 page 77.    I have never documented a boost condition.   I have temporarily run with two Arco SM-45's in series.....30 cell self regulating panels.........barely works

David

[dgd]

Td,
I had thought about those low cost voltage boosters from China, seen on Ebay.
Specs look good enough to use  150 watt 18volt mpv  panel to boost to about 35v for input to Classic/Kid charging a 24v battery.
But it would be nicer if the Classic/Kid did this boosting
dgd

[tecnodave]

Dgd,

Volume of production is making 125 mm and 156 mm cells the best price points, I am buying new last years model 72 cell panels at 80-90 cents a watt. Doesn't make sense to use the smaller panels anymore. I have phased out my CdTe panels due to real estate concerns. They did 9.5 watts/SQ.ft verses 13 watts/SQ.ft for my new Suntech and Sharp panels. I just bought 6 Top point 125 mm 72 cell 190 watt panels at 33 cents/watt. Siemens SM-55 are being traded away along with the dreaded Tracers, finally done with them.

td

[boB]

Siemens SM-55 are being traded away along with the dreaded Tracers, finally done with them.

What didn't you like about the Tracers ?  I had heard that they were at least, kind of "OK".

We have one but I haven't hooked it up yet.  Aren't they like, really inexpensive ?

boB

[tecnodave]

boB

They are kind of ok......and cheap @ $190 with remote control for a 30 amp unit but they do not properly charge FLA's.  The charge profile cannot be changed. They leave my GC-2's and L-16's at 1.220 s.g. And shut off. Even when on a group 27 deep cycle RV battery I need to run generator to top off the batteries.

I currently have one on system 3: 

One EP Solar Tracer 3215RN MPPT with 220 watts ,34.8 volts string 12 volt GC-2.
and a backup controller Trace C-40 PWM with 220 watts , 17.4 volt parallel, same battery set
All panels Siemens SM-55 55 watt 36 cell monocrystalline,

By 10:00 am the Tracer is done and the Trace is still charging at full tilt......?
The Tracer does put out 25-30% more power at bulk but total power for the day the Trace C-40 has done the bulk of the work........a MPPT controller outdone by a PWM controller....?

The one on a D-8 gel does much better, that charge profile works

EP Solar is a street light company and bundles up the 3215RN with two gel batteries at 24 volts, a LED controller for the light, and two CdTe panels at VMP 68 volts. This works very well but is not my use.

Service or technical help from EP Solar is non existant ...they rely on their dealers who know very little and will give you another unit to not post a bad review on Amazon about their units....yes I did take one to remove my scathing review on one of the units.

Bottom line......my gasoline use on the generator had been much lower when using good controllers to top the batteries off.......the Tracers forced me to top off the batteries with the generator due to their poor charge profile.

After that lesson of nearly ruining a new set of Interstate L-16's I bought the Classic 150 and very soon the first of the Kids and have never had that undercharging issues again.

Nobody beats MidNite service or technical help! I get awesome service from Schnieder Electric' Square D unit as I am a stocking installer of Squard D QO and Homeline products but this support has not filtered down to the Xantrex/Schnieder Solar division.   Too bad....that knocked them out of the running when I was making my decision to go with big controllers. MidNite and Outback were the finalists. It was a hard choice there but the support I found with MidNite sealed the deal....no regrets
I have 3 MidNite controllers now and will be buying a third kid soon.

David

<edit>. Spelling and clarity......I am a much better speller than my iPad is!