Off GRID Solar Power problem

[xibalban]

Hey fellas,

I visited an existing Off-GRID standalone installation which required repairs. The inverter-cum-charge controller had totally burnt off and requires replacement. The original rating cannot be read since it is charred and rest of the system details are as under:

• 36 V_oc, 6.8 Amp (rated current) 250 Wp Solar panels - 10 Nos
• 24 V (2 x 12 V in series) 400 Ah Lead Acid Sealed Maintenance Free Battery
• 400 W Load - that automatically switches on from dusk to dawn (Street Lighting Systems)

I'd be glad to hear suggestions for:

• The suggested rating of the Solar Inverter i.e. VA rating, ampere rating and battery input (24 V sure)
• The ways in which the Solar Panels are to be connected
• Rating of the Solar Charge Controller if I plan to buy one separately

Regards!!

[The Soulman]

36 V_oc, 6.8 Amp (rated current) 250 Wp Solar panels - 10 Nos

What is 10 Nos? 10 panels?

[xibalban]

Yes 10 Nos of Solar Panels

Also, I've found a 24V/30 Amp Solar Charge Regulator by Tata BP Solar. Unfortunately, I don't seem to understand the rating in it. The manufacturer is no longer in the Solar Business so can't ask them directly.

It only says 24V/30 Amp, and my confusion is:

• 24 V probably means 24V Battery. There is however, no mention of the solar input voltage range
• 30A is confusing though, does it mean load current or Solar input current?
• Can I connect 72 V (i.e. two solar panels in series) as the input? The current would be 13.6 Amps that way.
• How many such 72V Strings can I connect in parallel? Since the rated current output of each panel string would be 13.6 Amp, perhaps 2 such strings?? Still confused.