Configuration issues

Started by griffin87901, April 09, 2011, 11:31:42 PM

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griffin87901

I'm going to parallel 4, 135V, 1160 watt strings to total 4520 watts, 135V.  Would I need an MNPV 150 or an MNPV 300? Would I need one Classic KS or two?

boB

#1
Griffin,

Is this for 120 Volt battery bank ?   Reason I ask is that the 250 KS is mainly for 120V batteries although it will
work with lower voltages.

If it IS for a 120V battery and a 250KS is used, then one unit is fine for up to around 5kW into the battery but 135 Voc
would not be high enough voltage.

If 135 Volts (Voc) on the array, then a 150V combiner should be fine.

boB

K7IQ 🌛  He/She/Me

griffin87901

#2
Great question.  Yes this is for a 120 V battery bank.  I could raise the voltage up to 177v.

mike90045

Who makes a good inverter that runs off 120VDC ?
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

boB

Quote from: mike90045 on April 19, 2011, 03:44:14 PM
Who makes a good inverter that runs off 120VDC ?


In the US, Exeltech makes one in the MX series. (No, not an MX60 !)

http://www.exeltech.com/mxproducts.htm

Rack mount.  I know a guy on the east coast that uses these and two MX60s on each 60 Volt
half of his 120VDC battery bank.  He is ordering 4 Classic 250 KS controllers.  He usually
keeps two spare CCs, whatever he's using at the time.

There are other 120VDC inverters out there  of course but I'm not real up on them.
Australia uses a lot of 120VDC evidently which is why KS stands for "Kangaroo Special"

What is this about 177 Volts, Griffin ?  The 250KS only goes up to 150 VDC on the battery side
at the moment.

boB
K7IQ 🌛  He/She/Me

griffin87901

Laypeople and terminology don't mix well...  ::)

I meant that I could change my panel configuration to input about 180 VDC to the charge controller.  I was planning to parallel a couple of panels to increase the amps by keeping the input to the charge controller to around 135 VDC.  But since you said that was too low, I thought I would change my plan and put those panels in series for a total of about 180 VDC as input to the charge controller. 

According to the downloadable spreadsheet and the brochures, 125% of that is still within the limits of the 250KS.  Am I correct in my plan?

To answer the question about an inverters:  The output from the charge controller is to a battery bank in series to total 120 VDC.  The bank powers a 120 VDC motor from an American company, made about 1994.  No inverter needed, since it's all VDC.  Inverters take power to change from DC to AC, so I went for a DC motor.  AC motors also have great features, but efficiency was my top priority.