A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: qrper on September 20, 2019, 12:41:21 PM

Title: more solar panels that I thought possible. Time to expand
Post by: qrper on September 20, 2019, 12:41:21 PM
I never thought that I'd have more solar panels than I needed. Long story short, I purchased 40-250 W panels for a grid tie system. Seems the panels I purchased did NOT come with the UL, CSA, or ETL labels. According to the electrical inspector, he won't pass the system with those panels...GRRRRRR!!!

I used some of them to replace the old Solar MSX64s. the new panels quickly maxed out the Classic 150.

So as I understand it, I can't parallel another Classic 150, but it has to be by itself. Does That means I have to run another cable from the array, (more panels not connected to the ones up there now)  OR... can I parallel all the strings of the panels into one cable to feed two Classics?
OR... must the array be split into two different arrays to feed each classic?

Then do I use the follow me feature to charge the same battery bank with the two controllers?

thanks...

mike
Title: Re: more solar panels that I thought possible. Time to expand
Post by: Vic on September 20, 2019, 01:03:35 PM
Quote from: qrper on September 20, 2019, 12:41:21 PM

   ...   "So as I understand it, I can't parallel another Classic 150, but it has to be by itself. Does That means I have to run another cable from the array, (more panels not connected to the ones up there now)  OR... can I parallel all the strings of the panels into one cable to feed two Classics?
OR... must the array be split into two different arrays to feed each classic?

Then do I use the follow me feature to charge the same battery bank with the two controllers?

thanks...

mike   "

Mike,

YES   each Classic  MUST have its own separate array.  So you will need two additional cables.

You will need Combiners when you have three strings or more (or if you have three or more PVs in parallel).

The larger MN COombiners,   like the MNPV12 have dual Positive Buss bars,   that can be used separately.

And,   YES,  running multiple  Classics in Follow Me  is the best way to handle multiple  CCs on a single battery.

FWIW,   73,   GL.   Vic
Title: Re: more solar panels that I thought possible. Time to expand
Post by: qrper on September 20, 2019, 04:58:57 PM
Vic,

Kinda what I figured.

Now I take it the first classic decides when the battery is fully charge and, tells the other classic that it needs to change from absorb to float at the same time, too.
THAT being said, if the first classic has a WBjr installed, then adding a second classic won't that upset the wagon?

This might be a project for next spring 'cause the problems with my grid tie are continually mounting.

Mike
Title: Re: more solar panels that I thought possible. Time to expand
Post by: Vic on September 20, 2019, 07:27:29 PM
Hi Mike,

Follow Me coordinates the transition to Float,  the transition to EQ,  for the following Classic,   but IIRC,   the transition TO Absorb  is still done individually,   but that should not be a problem.   The following,   describes a Master/Slave configuration for  Classics FollowMe:
http://www.midniteftp.com/support/kb/faq.php?id=112

Because the WvJr Shunt is in the negative lead of the battery,   the Classic with the WB  measures the total current into and out of the battery,   and is visible on that CLassics MNGP,   and on the Local App.   No wagon upset.

Sorry to hear of your GT system issues.

Good Luck,  Vic

Title: Re: more solar panels that I thought possible. Time to expand
Post by: Tourville on October 03, 2019, 06:02:19 AM
I completely understand your frustration, Mike. Best bet would probably be to research the heck out of this during the winter and then go into action in the spring, like you said.
Title: Re: more solar panels that I thought possible. Time to expand
Post by: Matrix on October 03, 2019, 11:10:43 AM
Mike,  is your current system 24v or 48v.  Another option on the Max out issue of the Classic is to change the inverter for a 48v setup.  I am plotting ways to do this by selling off my existing 24v inverter so I can add more panels without adding another classic.  Pound for pound,  with selling the 24v inverter,  it might not cost me any more to go 48v rather than the cost of 2 classics.
Title: Re: more solar panels that I thought possible. Time to expand
Post by: Westbranch on October 03, 2019, 01:37:50 PM
Not that Classics have a bad track record, but things do happen unexpectedly.... and having a ''redundant CC'' hitched onto the battery  keeps the juice flowing, if not at your desired level...

I guess it is relative to the distance you have to travel to get one or even to the nearest phone to order one, shipping time etc... and how long you can hang on till a new CC arrives...
Title: Re: more solar panels that I thought possible. Time to expand
Post by: qrper on October 05, 2019, 05:16:54 PM
Quote from: Matrix on October 03, 2019, 11:10:43 AM
Mike,  is your current system 24v or 48v.  Another option on the Max out issue of the Classic is to change the inverter for a 48v setup.  I am plotting ways to do this by selling off my existing 24v inverter so I can add more panels without adding another classic.  Pound for pound,  with selling the 24v inverter,  it might not cost me any more to go 48v rather than the cost of 2 classics.

I started out with a 48 nominal system. The original charge controller was a Heliotrope General CC-60. Great tank built piece of equipment in its day. Retired the old heliotrope and went with a classic 150.

Changed out the 64 W solarex modules with 250 W ones.

mike