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Elimac avatar image
Elimac asked

Expanding Multiplus standalone to 2x in Parallel

I'm about to expand my system from 1x Multiplus 24/3000/70-16 to 2x units in parallel, so I can have more inverter power. Currently, overload warnings/alarms come between 1800 ~2200 W depending on temperature.

I would like to ask community what are the important points to observe. I have read the manual, but is seems more focused in 3 -phase systems.

Things that I already had in consideration:

1. Ordered an unit that has similar hardware characteristics, informed that it was to match current unit

2. Ordered an MK3 so I can update my current Multi to same firmware version.

3. I will arrange a DC bus bar so both Multipluses see the same voltage from DC in

4. I will arrange an AC board so both Multipluses have same input and output AC wires lenght


5. Now my question: my current Muliplus is controlled remotely by the Venus, changing from GRID to Solar according with my needs. The Venus relay is physically connected to AUX1 of Multiplus, and I have programmed General Flag and Programmable Relay assistants to current Multi so I can change the operation mode (charger or inverter). Will I need to wire also the second Multiplus? I think so, but just to be sure. Any problem about this? Will they switch at same time?

Any other advice?

MultiPlus Quattro Inverter Chargerbattery charging
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oxy avatar image oxy commented ·

> 1. Ordered an unit that has similar hardware characteristics, informed that it was to match current unit

That's actually pretty interesting - was it challenging to get a new MultiPlus to match your existing one? I'm having an issue where I need to add a second MultiPlus to double the power, but the dealer says ours is "too old" and its impossible to upgrade the software...

https://community.victronenergy.com/questions/18300/increasing-old-multiplus-5000-setup-to-10000-va-pa.html

My MultiPlus is at "1959143.VFD" version, what version your MultiPlus processor is?

Thanks!

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boekel answered ·
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Elimac avatar image Elimac commented ·

I have read that manual, as I said. It does not answer my question 5, does it? Do I need to connect both AUX1 relays to Venus or not?

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boekel avatar image boekel ♦ Elimac commented ·

Did you read this?
https://www.victronenergy.com/live/ve.bus:manual_parallel_and_three_phase_systems#assistants

It depends on what assistant you use, and you didn't specify which one you use...so I'd have to guess to help you...
Is it an ignore AC-in assistant? then I think only the master, as the units switch together.

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Elimac avatar image Elimac boekel ♦ commented ·

I have written in original post, no need to guess:

"I have programmed General Flag and Programmable Relay assistants to current Multi "

My doubt is about the physical connection. Maybe both mutis expect / need signal on AUX1, and not just the master.

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boekel avatar image boekel ♦ Elimac commented ·

But what are you switching with the general flag assistant? ignore AC-in?

As the unit's switch AC together, you only need to do that in the master.


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Elimac avatar image Elimac boekel ♦ commented ·

Great! Yes, in deed, the action is to ignore AC, I forgot to mention. Is like this:


So, in reality, if one wants to switch the set of parallel units to ignore/ not ignore ACin, it is only needed to command the Master unit, and the slaves will follow with same action, trough the VE.Bus wiring. No need to also command / wire the slaves on the AUX1 input. Let me know if the conclusion is correct.

Thanks!


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