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Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: Westbranch on December 01, 2011, 10:34:47 PM

Title: strange Simulator results in wire sizes
Post by: Westbranch on December 01, 2011, 10:34:47 PM
I just ran 2 scenarios on the simulator
1 - 3 strings of 4 panels
2 -  6 strings of 4 panels
Voc 22.2 Vmp 17.7  Isc 7.61 A Imp 7.06 125W

When I ran scenario 1, I was given a minimum wire size of 8 AWG, for scenario 2 the minimum wire size was 2 AWG (Combiner to CC).

How does the built in limiter in the program set the minimum wire size you can test against?

the reason I ask is that I have used another wire size/Voltage drop calculator and I can meet % drop specs with smaller wire size.

ej
Title: Re: strange Simulator results in wire sizes
Post by: Halfcrazy on December 02, 2011, 06:07:11 AM
Whats the distance one way?
Title: Re: strange Simulator results in wire sizes
Post by: Westbranch on December 02, 2011, 12:04:23 PM
sorry, I used 20 feet one way. I used different distances and no difference???
Title: Re: strange Simulator results in wire sizes
Post by: Westbranch on December 05, 2011, 07:43:45 PM
Ryan, any ideas?

Eric
Title: Re: strange Simulator results in wire sizes
Post by: boB on December 06, 2011, 01:45:31 AM

Hey, Westbranch...

What simulator is this ?  The one in the Classic or the one on our web site ??

boB
Title: Re: strange Simulator results in wire sizes
Post by: niel on December 06, 2011, 05:46:14 AM
or are you referring to my v drop calculator?

the total wire distance for pv to combiner and the total wire distance from combiner to cc would be needed. of course the total distance is the run distance times 2. say what gauge of wire for pv to combiner and combiner to cc you are using in your calculations so we know the whole scenario.
ps-are the wire runs from both pv arrays to be the same wire size and length to each other or are they different?
Title: Re: strange Simulator results in wire sizes
Post by: Westbranch on December 06, 2011, 12:41:28 PM
boB, it is the web site one.  Checked it out several times in case I made an error, same result regardless of distance for the 6 string scenario 2AWG. 3 string was 8 AWG.

Niel, for your calculator I used 6 strings @ 48 volts PV, battery 24 V, (double distances of) 40 feet/ 10 AWG, 30 feet/8 AWG, 4 feet/8 AWG, 8 feet/4 AWG.  > = 2.76% and 3.55%

All distances are overestimates of actual at this time.  Attempted to determine the minimum wire sizes needed with < 3% loss.  What it told me is to go as far as possible before combining...

Yet the web version Classic simulator even with a total distance combiner to CC of 20 feet, yielded  a result of 2 AWG Comb. to CC .  ???
Title: Re: strange Simulator results in wire sizes
Post by: boB on December 06, 2011, 06:42:50 PM

W.B.  Have you tried the same thing on the Classic's Wizard ??  I wonder if the web site and Classic both agree or disagree...

As long as you don't complete the Wizard, it won't (read... "shouldn't") change settings on your Classic.

boB
Title: Re: strange Simulator results in wire sizes
Post by: Westbranch on December 06, 2011, 06:54:23 PM
Hi boB, I don't have a classic yet, so can't use its wizard.  :(
Title: Re: strange Simulator results in wire sizes
Post by: boB on December 06, 2011, 09:37:57 PM
Quote from: Westbranch on December 06, 2011, 06:54:23 PM
Hi boB, I don't have a classic yet, so can't use its wizard.  :(

OK, we'll check it out.

boB
Title: Re: strange Simulator results in wire sizes
Post by: Westbranch on March 08, 2012, 03:04:27 PM
bump  ??