Author Topic: Breaker box or combiner suggestions for 6 battery setup  (Read 54 times)


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Breaker box or combiner suggestions for 6 battery setup
« on: May 15, 2017, 12:43:39 PM »

A customer has an off grid system with 6 each, 48 volt battery banks, feeding an inverter / charger.

They did a nice job on the installation and it is working well and staying in balance.  They installation is mostly stationary, but it can be occasionally moved, so the wiring is typically stranded wire and closed lugs.

The one thing that they don't like is that it is "fused" vs "breakers", and they want to upgrade to an all breaker based setup.

The configuration is:
- Each of the 6 battery banks has a 40 amp fuse between it and the bus bar
- From the bus bar to the inverter / charger is a 200 amp fuse, but this could be replaced with a smaller breaker in the 150 - 200 amp range.

I am thinking about 2 options for them and am open to suggestions:

Option #1 - based on surface mount breakers

a) 6 each of the MNEDC-40 breakers for each battery bank connection to the bus bar
b) 1 each of the MNEDC - 175 breakers for the main disconnect (bus bar to inverter / charger)
c) Need to find a suitable panel to mount it in - need suggestions please
BTW - this is my preferred approach if I can find a way to put it all together as that way I can use 4 AWG wire with closed lugs for the smaller wire and 1/0 or 2/0 for the main connection to the inverter.

Option #2 - based on din rail mounted breakers

a) 6 each of the MNEPV40 - for the battery bank to bus bar connection
b) I think that I still need to use the MNEDC - 175 breaker for the main connection to the inverter.

I am open to purchasing a pre-made / pre-wired seutp.

The aspect that I think that I am running into is that the MNEPV40 150 VDC din rail mounted breaker is polarity sensitive, but it appears that the 80 VDC version is not. 

Are there any other concerns / suggestions that I should be thinking about on this?




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2 x 3Kw on Trailers & 1.44Kw ThinFilm on Trailer
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Re: Breaker box or combiner suggestions for 6 battery setup
« Reply #2 on: May 16, 2017, 02:41:20 AM »

And you have room for some Charge Controller and accessory breakers as well...

Thank you very much for pointing out that box.  It is perfect actually.

I have a few more things that could potentially fit as well.

Do you happen to know if it can support both nominal 48 vdc and 120 vac breakers at the same time, or does that require special separation setups? (edit - I looked at the manual, I don't think it supports both AC and DC, only AC)

I will put together a list of parts and post it here for review / comments.


« Last Edit: May 16, 2017, 03:07:07 AM by harryn »