midnite classic creating 117V at pv input

[dgd]

So how would that work with panel having blocking diodes installed in them ?
I have seen one 300W Canada Solar that was damage on shipping (fork from lift truck pierced it) And on disposing of it , I noticed black diodes in the wire combiner box.

I seem to remember the diodes installed in solar panels are usually bypass diodes and not blocking diodes.
Blocking diodes are usually installed externally

http://www.solar-facts.com/panels/panel-diodes.php

dgd

[CDN-VT]

Ok , I read that , So how is the panel fed power to use for heat ? reversal is / has been posted .Both Diode pix are one way & anti reversal , Zener diodes are Bi /till voltage . 
Please explain ,

So I need to see what & what im missing , of how to back feed heat /power or to feed in flow power ? that I can't see heat on a factor of % to make the power input worth the heat .

VT

Can't spell

[Halfcrazy]

If you elevate the panels voltage above VOC it will generate heat, the higher above the VOC the more current it will conduct.

[CDN-VT]

So from Ryans explanation , there would be no blocking diode .
I can see the cells receiving power with just bypass diodes .
Must be some amount of power to overcome some VOC on series wired panels
and then shed amps to heat them .

Thanks for the update.

VT

[dgd]

This feature of solar panels can be put to use. As boB mentioned some time ago the PVs can be used to clip an attached wind turbine with the Pvs OCV becoming the clipping voltage. As turbine output exceeds this the excess is used to heat the PVs and slow the turbine
It would need some thought to get the design right with the voltages but would enable a PV array and a paralled wind turbine to be connected to inputs of a Classic.

dgd

[Halfcrazy]

Yes that used to be done a lot with hydro. Make sure the PV is larger than the hydro and make sure the pv vmp and hydro vmp are similar. Then as the battery gets full the MPPT lets go and the hydro heats up the panels slightly but the panels become a clipper

[dgd]

So if I lived somewhere where snow covered my PV array AND there was wind to get a turbine really moving then clipping the turbine voltage using the PV array would also clear the snow off the array.
Then we would not need a 'reversing' Classic 

dgd

[CDN-VT]

Here we use a rubber edge snow rake if need be.

If we do have a build up of snow it's direction off the panels is still downward , so I'll need to blow it somewhere .

After the panels are semi clear the sun can do the rest , if it's still snowing then i don't think you can beat the melt with powering the panels HERE.
VT

[ralph day]

I've tried to use a snow rake, but not the rubber edged one.  I have a brush about 16" wide on a pool cleaning extension rod for panel cleaning now.  The snow rake would get caught on the roofing screws on the steel roof, and on the panel mounting hardware on the arrays.  The brush doesn't.

Ralph

[CDN-VT]

Ralph gets much fluffier snow than us  on the wet coast .
Our snow is heavy wet pack . I modified the snow rake in the posted Pix ,
I went to a janitor type store & got a replacement floor squeegee rubber & then drilled & used aluminum strip to secure .
on the handle side I installed a wing so the rake only go's down 6-8" in the snow.
For us wet-coasters , we need to remove the snow evenly from the roofs, take off 1/2 on one side & then 1/2 off the other till you have unloaded evenly .
We don't normally get snow , but with them fooling with the weather , 3 years ago we were hit with 6' in a week .
I had  both snowblowers going & 2 roof rakes while we were on pruning ladders pullin ,pushin & blowen for a month .
Snow belongs in the mountains or back EAST !! 

I posted the Pix of the snow rake for  W Auckland,many might think I was pushing their chain with snow snakes & rakes ..
Hard to see white snakes , but if ya ski , them-el trip ya up every time

[boB]

So if I lived somewhere where snow covered my PV array AND there was wind to get a turbine really moving then clipping the turbine voltage using the PV array would also clear the snow off the array.
Then we would not need a 'reversing' Classic 

dgd

Unfortunately, with enough snow on the panels and anything lower than 20 some degrees F outside, you will most likely blow the PV's series fuse when trying to melt snow

BTW, the newest Classic firmware (2079) will not stay on with zero forward watts (into the battery) for very long.

What happened before was that if the Classic was in Float or Absorb (or EQ) with little or zero output watts/amps,
like if the battery voltage was being held up by another charger or whatever, it would stay on.

Merry Christmas, almost.
boB

[zoneblue]

Bob, 2079 looks  to me very much like the firmware that throughly put the icing on the christmas cake.

[boB]

Bob, 2079 looks  to me very much like the firmware that throughly put the icing on the christmas cake.

This is great to hear !!  (I think it's good, anyway ? )

[dgd]

BTW, the newest Classic firmware (2079) will not stay on with zero forward watts (into the battery) for very long.

What happened before was that if the Classic was in Float or Absorb (or EQ) with little or zero output watts/amps,
like if the battery voltage was being held up by another charger or whatever, it would stay on.

I'm not sure this is a great idea, it may be for a system with a single Classic but what happens if there are two or more Classics charging the same battery bank?
Since there is no charge balancing between Classics where they share the charge requirement between them then what happens now is that one Classic will maintain the Float charge needed by the battery and the other(s) will stay in Float but have zero amps out to the battery. If the one providing the Float current falls below the required amps then the other(s) will start moving out amps to make up what is required.
Now if you are going to force the zero output Classic to resting then how can it waken up in Float state to make amps to maintain the battery Float state?
Will it come out of Resting and go into Bulkmppt mode? which would then have the potential to overcharge the battery.
And 'follow-me' would not be a viable solution for this as the Classic that was maintaining Float would move to zero amps output as the woken-up Classic did Bulkmmpt. In turn then the Float Classic would go to Resting andbe woken up again in Bulkmppt mode.
As they say SNAFU 

dgd

[dgd]

BTW, the newest Classic firmware (2079) will not stay on with zero forward watts (into the battery) for very long.

Perhaps a modbus register could be used to enable/disable this feature
With the LA having a config line to do this?
Or have it disabled if follow-me is not implemented?
Or better still, get charge sharing implemented
And get follow-me implemented over ethernet using an ip-number table on each Classic so that the serial ports can be used for proper applications (inc W10 firmware updates) 

dgd