Advice on dual 3kw (6kw total) system for small concerts?

mattleonard

Solar Enthusiast
Joined
Mar 8, 2020
Messages
54
Location
Oakland, CA
I'm looking to build out a cargo trailer that can provide power primarily for mobile sound/PA systems at festivals and rallies- and looking for any advice on the general concept, design, or equipment options.

I'd like to be able to supply around ~6kw at 120v AC. But I'd also like to have modularity and some redundancy (even if not full). I am thinking of both fixed rooftop solar on the trailer, as well as having the option for a couple more portable panels that could be hauled out of the trailer and setup when practical.

Basically - I'm thinking of 2 entirely discrete systems in a rolling wooden road case - each having ~7200wh (300ah of LifeP04 at 24v), a Victron Multiplus 24/3000, and an MPPT. This lets me have (2) smaller systems when needed (modularity), and if one goes down for some reason - I could limp along with half power (some redundancy).

For the output side - I am thinking each unit could run a pair of 15a/20a Edison circuits (with appropriate breakers). On the input (charging side) - I'm thinking the solar (both rooftop and portable panels) could be on Anderson plugs for quick reconfiguration. I don't see a need for 30a or 50a shore power - but having 20a Edison input would be nice.

When running units in parallel like this -what grounding considerations do I need to think about? They would be powering different devices on different circuits - but those devices would often be grounded/connected via audio lines. Should I bond the inverters together? Or bond the various AC outlet grounds?

And lastly - any advice on the grand plan? Should I just do a single larger inverter and keep it simple? Connect batteries into a single bank and both inverters share that?

Thanks in advance!
 

Rocketman

Solar Addict
Joined
Sep 27, 2020
Messages
698
Will you ever need 240v? (Split phase)?.

If not... Kiss - keep it simple. I would think it would be better with one larger inverter 24/5000 than 2 smaller ones 24/3000. If that fits the power budget. Or combine the two Multiplus’s into one power stream


Have you ran a complete power budget? Looked at and added up the amps and watts of every piece of equipment? The last thing you would want is to get half done with the concert and have power be done. Also, look at the spec sheets on Victron- the inverters will get hot - will they run everything once they start to derate because of getting hot.

Good Luck - it sounds like a good project. (Sorry I didn’t answer the question on bonding - I don’t know enough to know if that would be an issue)

This bonding question may be better answered on the Victron Community...
 

mattleonard

Solar Enthusiast
Joined
Mar 8, 2020
Messages
54
Location
Oakland, CA
Thanks for the feedback. I don't forsee a need for split-phase - though I can see the benefit of running a single large 30a/240v cable to a power distribution center (like the spider-box/temp power ones) closer to the load, rather than multiple 15/20a 120v cables the whole way. This would also give more flexibility to park the trailer/panels where the sun is, and lower voltage loss on 120/240 than on the panel string.

I've done a power budget - but this isn't for a specific set of equipment - it will have limitations that I'll always be mindful of. But, having ~6kw of output will suffice (until I add a 3rd Multiplus?) - and expanding the battery banks is always an option too.
 
Top