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Proper use of terminals

Burnt TerminalJust as a reminder that the charge controller has two sets of terminals for each input and output. This is a vital part of the controller and being able to handle as much power as it does for being so small.  IT is imperative that if you use the controller over 50% of its max amperage that you USE BOTH TERMINALS. this will distribute the load between two solder connections thus reducing the heat one each solder lugs.

Trying to run 60amps of current through a single terminal will build enough heat to melt the solder and destroy the terminal block

Also, Male sure that you strip the wire only long enough to fit in the terminal block. Stripping wires to long will leave enough bare wire to have a direct short with case or other wires. This can destroy the cpu in the controller and render it useless.

Hey Sean, what size wire fits the terminals on the 60amp MSB ? ....... Rod

10 awg fits nicely.

 

 

Thanks

Hi there, I have a 60A V119 MSB MPPT on order from Germany via MSB website - I am not getting a lot of support from their sales messenger service, either MSB or Germany. I see that if I have single solar feed it is best to split it over the two terminals (which I intend to do). I also saw somewhere that this can be done by simply dividing the wire strands between the 2 terminals. Is this a adequate solution if I insulate the bare strands leading up to the terminals? Hope this is not a stupid question. Thank you

Sorry for the lack of response from MSB.  To answer your questions. yes you can splt the wire but on the PV input usually there is no need. Each reminal is good for 30 amp.

So if your under 30 amp in the PV in.. your good with one terminal.

Thanks

sean

Hi Sean - I very much appreciate your kind help. I over sized the PV wiring in case I wanted to upgrade from my 2KW - 76 VOC grid tie system. When I added batteries and SCC (eSmart3) - I reconfigured my array so now have 152 VOC running on 6 AWG off the roof. This leads to an obvious terminal problem I am guessing. By splitting the strands it not only helps reduce the load/heat on the terminal but will hopefully allow me to get the wire to fit in the terminal in the first place 😀

Another question if I may - the wiring available in France is stranded but using very thick strands - my 6 AWG has 7 strands - if I divided them 4 + 3 would the imbalance cause any issues?

The eSmart is still  working reasonably well but I have lost the ability adjust the charging parameters and when I asked for help to remedy they basically said - tough - its an old model - buy a new one!!!

I only bought it in December 2019 - hence the conversion to MSB

Keep up the good work - this is an awesome forum

Kind regards

Peter

Peter,

That should be fine with no load balancing issues.

Thanks for the forum compliments. I try hard..

 

Thanks

Sean

I would like to suggest  my solution, as I found this is the best way for the terminals, both from practical and engineering point of view.

I'm using 6AWG from the panels to the controllers and to the battery banks.

I found "fork" terminals in local hardware shop with perfect fit in dimensions for the terminals but not for the 6AWG so I had to discard the plastic insulation on them, had to use shrinking tube insulation and solder the forks instead using clamping tools. Soldering is also a safer joint than clamping.

 

Here what it looks like right now.

 

I believe you'll find it helpful and easy 🙂

Thanks for the method - great idea that will help me a lot 😀 Peter

Thats Awesome stuff... Thanks for the input ...

Ill be utilizing this method also..

Sean

Just an observation. There are no screws holding the MPPT? Is it laid down flat? The backing support looks like a great heat sink also? I am intrigued! Peter

Yes peter on this photos it's laid down on a DC power distribution unit.

I took it from wall where it's fixed just to take photos, that corner was to dark for my camera.

Another question - sorry. I currently have a BMS on the negative cable between my SCC and my battery. I see in the manual it says no meter or other device between SCC and battery. Any advice on whether this is a definite 'must not'

In case of open circuit at he battery terminals, the "high" voltage from the PV's can damage the SCC.

I believe that's the reason...

MSB instructions are bit hard to understand, as there are no explanation about their statements.