Classic 200 Patrial shading loop -

[janmnsc]

Hi MNS

I have a CL200 in a 24v configuration.
4 Strings of 5x120w the PV VOC is 42Volt (20 Panels)
A once high monitored VOC 203v. Every day high VOC +- 186Volt
https://www.mymidnite.com/drupal/?q=user/669

Device information:
DFB3 1D20
serial  cl 17565

Scenario 1: Mode Solar
Drain battery during evening and charge during day way past midday without drawing high currents and charging at high current of 64A. (winter here now)
No problem CL200 works as advertized. I love it here.
This is not sustainable as I need high current during the day from battery.

Scenario 2: Mode Solar
Drain battery during evening and charge during day till close to midday and inverter draws high current from battery 110 amp @ 24v falling to 23.3Volt.
CL200 goes in Partial shading loop and energy collected drops drastically.
During this time: Change Mode to LEGACY  P&O
This takes a few seconds and stabilize to where Solar Mode would have been.
MPPT seems to work fine for the rest of the day as Voltage will vary and Power varies to charge battery and supply high load.
see 26Aug15 on mymidnite.com after 11:18(am)

Scenario 3: Mode Legacy P&O
Start the day in this mode.
Drain battery during evening and start charging. All seems well at first.
Early morning the Volts in goes to 172Volt for rest of the day.(see 24Agu15 - mymidnite.com)
Very low yield on a 100% sunny day. Seems no MMT done.

Legacy P&O is not usable for me to keep my CL200 on this setting.

Could you please have a remedy for me to stay on Mode Solar?

P.S.
My setup with 4x120w panels per sting (16xpanels) and a VOC of 161Vols worked fine.

[Vic]

Hi janmnsc,

Some of the earliest Classic FW would also get into this Shading loop ...

What Firmware version are you using?

You might try disabling Shading in the Tweaks menu  --  press ' More ' about three times,  and there should be a Shading On/Off ...  down arrow should turn Off Shading.

This should be a Menu Map (for FW V. 1933):
http://www.midnitesolar.com/pdfs/classic_menu_map_rev_1933.pdf

Have no other ideas.   Good Luck    Vic

[janmnsc]

Thank you Vic.

I will try this for tomorrow's harvest. This will be so nice if it works.
Firmware is latest.

Regards,
Jan

[boB]

Yeah, sometimes it doesn't work as good as it should or could when something is not quite right.

Try Legacy P&O mode as a sanity check.  See if that mode helps.

boB