replacing C40 with Classic 150

[Westbranch]

A friend is going to upgrade his woefully under PV'ed (300W) 24V system which he has hooked up to his  BRAND NEW 940Ah battery bank.  Powers a Trace inverter/charger.

I convinced him to start with a Classic 150 so we could at least get some MPPT kick while he decides what panels to buy.  Not much but every bit helps to keep the batteries healthy at this point.

He wants to go with panels => 200W, and we will configure them to (probably) 48 V or greater if the
'150' will allow it.  distance is est at 80' one way  to the array site.

We plan on a new MNPV 3 or 6  combiner box depending on configuration.

Based on the 'normal' wiring configuration of the C40, will a Classic 150 be a 'plug n play' install to the existing wiring?  

TIA
Eric

[Halfcrazy]

Yes the Classic uses the same sort of wiring Battery+ PV+ and common Negative. That said the Classic 150 is a lot more powerful than the c series so you may want to upgrade the breakers and wiring if he plans on expanding the pv system.

[RegGuheert]

He wants to go with panels => 200W, and we will configure them to (probably) 48 V or greater if the '150' will allow it.  distance is est at 80' one way  to the array site.

Hi Eric,

One thing you might want to consider is that if you are going with 60-cell PV panels, you are limited to strings of three panels if you purchase the Classic 150.  Personally, I find strings of three to be a little cumbersome to work with, but that will also depend on the layout of your array.  If you go with the Classic 200, you have the option to work with the 60-cell panels in strings of 1, 2, 3 or 4.  If you use strings of 4 panels your peak power point is around 120 V which will help reduce wiring losses in your 160-foot round-trip circuit.

OTOH, apparently the efficiency of the 200 is slightly lower than that of the 150, with the break-even point being at "PV runs" of "100 feet" according to the Classic manual.  MidNite does not indicate whether this is one-way or round-trip distance or what the wire size implied in this assumption is, but suffice it to say that you are near the break-even distance for efficiency.  Since you have a small existing array, I'm guessing you might be trying to re-use fairly small wires and/or conduit which are already in place, so going with the higher voltage will likely help, if not be a necessity.

Anyway, just something to consider...

Reg

[Westbranch]

Thanks for the feedback,  the new panels will be in addition to the existing array.  
So all new hardware to be sized/used for the new panels.  
We will re-plumb the old array with the C40 CC once the new array is on stream. Ed wants to align the old panels for afternoon production with the new ones aimed to solar noon. Looks like 10 panels, 2350W.  
I had suggested '12V' panels as they allowed more flexibility, based on our cold winter temps -45F in these parts or lower, it looks like the 150 will only allow 2 panels in series; at -40F, 3 panels are within range (used Kent's spreadsheet).

More to come when he decides on the panels.

Eric