question

matt-m-1 avatar image
matt-m-1 asked

DMC 200/200A with non-parallel MultiPlus

For anyone not familiar with RV shore power (at least in the US/Canada), there are two options - 30 amp and 50 amp. 30 amp is entirely straightforward - 2 wires plus ground, 120V 30A across the two wires. 50 amp should really be called “100 amp” because it is three wires plus ground, so there are two “legs” with 120V 50A across each leg (100A total). You could run 240V appliances across the two hot wires, but there are no 240V appliances in my RV, so each leg originally attached to 1/2 of a split breaker panel, with half the appliances on each leg.

When I added the batteries/solar/inverters, etc, I installed two MultiPlus 24/3000/70 inverter/chargers, one attached to each shore power AC input leg. I then attached the AC output of each MultiPlus to 1/2 of the split breaker panel. So even though I have two Multiplus units, their outputs are not connected to each other. I.e., it is neither a split phase nor parallel installation. The only connection between them is the connection to the battery bank.

I now wish to add a DMC 200 control panel so I can quickly adjust the input power limit when I attach to a generator or 30 amp shore power. In both cases, a dogbone connector sends the single phase 30A power to both legs of the 50A shore power connector, so I need to set the MultiPlus input power limit to 15A each to avoid overloading the generator or popping the shore power breaker.

(finally) My question is: Can I connect the two MultiPlus units together (master/slave) via RJ45 and then attached a single DMC 200 to the master even though they are not connected in a parallel or split-phase configuration? Put another way, is it OK to connect the two MultiPluses with RJ45, even though their AC outputs are not connected together?

Thanks!

Digital Multi Control
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

If you connect them together via VE.Bus they have to be configured together as split-phase, otherwise they will just switch off the moment you connect them together.

Or you don't connect them together and use two DMC.

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matt-m-1 avatar image
matt-m-1 answered ·

Well that's disappointing. I guess I can look into joining the two halves of the breaker panel then running the Multis in parallel. We'll see....

Thank you!

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matt-m-1 avatar image
matt-m-1 answered ·

No that won't work because when I plug in to 50A shore power they will be out of phase. I guess two DMCs.

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