Midnite Classic 150 produces no power whilst in Solar / Bulk Mode

[ClassicCrazy]

Did you say which firmware version your Classic has  ? I looked though all the previous posts but didn't see it or I missed it.

Larry

[NoPowerBills]

The latest. As far as I know there is nothing after 2126

[NoPowerBills]

...a back-feed situation and damage , in your system ,  to the whole ARRAY....

hi, why would a string of 3 panels spontaneously "back feed"? The Array seems happy to deliver enough power to the capacity of the classic, eliminating the possibility that the array is damaged. Also there is no evidence of physical damage, so not sure what you mean by a series of panels (3) "back feeding".

[Vic]

Thanks.

Sorry - I didn't fully understand your question on the combiner. 3 strings run to an isolation switch and then DC breaker. Other 4 strings - isolator - DC breaker.

Panels are: https://www.solarquotes.com.au/panels/sunearth/tpb156x156-72-p-250w.html

As mentioned, on a slow morning (hazy, foggy start) The CC will show Bulk Mode, near Voc - consequently no current, until rebooted or mode changed followed by a mode on/off. A mode on/off does not start the charging.

Hi   N P B,

Thanks for the PV info,   here is a Link to the complete date on those:
https://www.enfsolar.com/pv/panel-datasheet/Monocrystalline/5003

These PVs should be fine as far as minimum string Vmp is concerned for strings ot three.  Just run the Classic Sizer with all of that data,   and look at the Vin for your lowest temperature of record for your site ...

As was noted before,   you must run  the Classic Firmware and the MNGP versions that are compatible.   Please let us know what is your MNGP FW Version #.

Believe that Down Under,   an "isolator",  is  a DC relay ?

The DANGER in not running a real Combiner with a DC breaker for EACH PV string,  is that if one PV develops a Fault,  like a short,  that as many as six other strings can run  its Isc rating into that one PV.   This could be as much as about 42 Amps combined into that one PV.   This can easily cause a FIRE.

No time now,   gotta get to work.     FWIW,   Vic

[Westbranch]

Vic, thanks for answering that much more simply than I could.
ej

[NoPowerBills]

As was noted before,   you must run  the Classic Firmware and the MNGP versions that are compatible.   Please let us know what is your MNGP FW Version #.

Hi, From the Status App:

- Classic Rev: 2126
- Network Rev: 2097

So the MNGP will be the latest, it's all embedded in the one download - 2126. And both the Classic and the MNGPw were updated in the same session.

Point taken about the combiner - if 3 panels in series fail/get damaged, there could be a "backfeed". But since this is not happening now, can we leave that as a future project and not the cause of these weird non-start days? BTW the maximum current in such a situation would be closer to 27A (ie. string of 4, one fails leaving 3 at Isc - right?)

Thanks for the info though.

[Westbranch]

N P B in 'the normal situation, where there are more than 2 panels in series' you would have 0ne breaker for each string of 3 PVs and the 'connection' would be in the combiner box. It only takes out 1 bad panel to cause a back feed... in the normal setup that would eliminate 3 panels total..., the one that failed and 2 more that were in that string....

However the way you have connected it, 1 shorted PV , has the potential to Kill off all your PVs and probably cause a serious fire...

[ClassicCrazy]

The latest. As far as I know there is nothing after 2126

Not that you need it but the new talking version of firmware is out there in beta form though seems to be just fine
2154 6/26/17  MNGP
2151  5/26/17  Classic
2122   network

Larry

[NoPowerBills]

Since nothing else has worked it may be worth trying this F/W. Where to find it? Nothing on the Midnite site:

http://www.midnitesolar.com/firmware.php?firmwareProduct_ID=1

[ClassicCrazy]

Since nothing else has worked it may be worth trying this F/W. Where to find it? Nothing on the Midnite site:

http://www.midnitesolar.com/firmware.php?firmwareProduct_ID=1

Instructions and links are in the document in the first post of  topic below --   Voice Beta .docx

http://midniteftp.com/forum/index.php?topic=3746.0

Larry

[NoPowerBills]

Thanks Larry, no way would I have found that on my own!