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Topic: victron multiplus compact install in a U280 install advice (Read 1532 times) previous topic - next topic

victron multiplus compact install in a U280 install advice

Hi all!
I'm on a roll. Moby the White Whale is showing its age, but is plugging along nicely. The original Atwood waterheater has been replaced with a demand heater, at last, and we're back to making full boost (who would have thought that the fuel cutoff solenoid was that sensitive as to how thick the mounting gasket is? Too thin and the fuel lever only allows 4psi), so now it's time to install the Victron. The PACS that was in there turned itself into a boat anchor. So did the inverter transfer switch under the bed, near as I can discern. Since the new inverter has a charge controller and all that built in, and puts out twice the watts, I want it to run the whole coach instead of running it through the these-circuits /those-circuits switch. When last I looked here, someone here mentioned being able to do this but I just cannot find the thread. So.. I *think* what I can do is: connect the batt charge cables to the charger terminals, connect the house batteries to the 12V in terminals, and then (and this is the part that makes me nervous} insert the 120V in and 120V output upstream of the main shorepower/genset transfer switch? At least I think that's what I'm getting when I read the manual on this thing, that it can throughput shore power and then internally switch when unplugged. But I want to see how wrong I am *before* I start in on this!

Re: victron multiplus compact install in a U280 install advice

Reply #1 –
Tom Long @T and M Long  did a great Install in his coach.  Job looked better than if he would have had professional done.  I think he even did a thread on the project on here. I bet he will Chime in when he sees  this.

Re: victron multiplus compact install in a U280 install advice

Reply #2 –
Probably putting the whole coach on the inverter is not the best approach and usually is not done that way. The base is the transfer switch for shore or generator power feeding the main distribution panel. Then a branch circuit from that panel feeds the inverter-charger with the bypass relay. If over 2,000 watts or 20 amp feed through, then it feeds another distribution panel. The loads you want on the inverter then get moved to that second panel. It is done this way for a number of reasons including overcurrent-short circuit protection and coordination and management of the ground-neutral bonding for the inverter powered loads. 

Re: victron multiplus compact install in a U280 install advice

Reply #3 –
Yes I did a solar/ lithium house batteries and inverter ( victron multiplus II 2x120) on my coach.. I am very happy with my setup, for how we use the coach. For my skill set it was a complex, time consuming project. I spent a huge amount of time researching the project. I also got technical help from Dan Henning at Rv Solar Consulting. My set up would not be for everyone. There are a lot of variables on making fundamental  changes to a coaches wiring system. You have to understand before you start. As much as I would like to help. I think there is a lot I don't know about your coaches current configuration.
I hope you have the original wiring diagrams from Foretravel. I used that as a starting point to figure out how to integrate the new with the old. I wish you great success on your project. I think Dennis H is right, with what you are trying to accomplish. I also know he has a lot more overall knowledge on the subject than I do.
Tom

Re: victron multiplus compact install in a U280 install advice

Reply #4 –
Also if you would post the exact inverter model#. I would be interested in looking it up.
Tom

Re: victron multiplus compact install in a U280 install advice

Reply #5 –
I don't see a model # for this thing. The part number is CMP122200102. It's a charger/inverter/transfer switch and it's that last bit that gave me hope. What I'm going to do is wire it up exactly as the original was and see if the tranfer switch under the bed still works, and go from there.

Re: victron multiplus compact install in a U280 install advice

Reply #6 –
That's the MultiPlus Compact with an 80 amp charger 12/2000/80-50 120V VE.Bus (UL 458). You can't power the whole coach with that inverter because it only has one hot leg. You would need the one another member posted above, which is the 3k watt Multiplus II 2x120. Neither of these two inverters have a "transfer switch".

Re: victron multiplus compact install in a U280 install advice

Reply #7 –
I may have bought the wrong inverter then. Would only having only one hot leg keep the xfer switch under the bed from working? I have plenty of 12v going in, plenty of 120v coming out on the L1 leg, nothing (as noted) on the leutral leg, and the xfer switch under the bed is unimpressed. No hum no volts at any outlets etc.
The control panel that used to run the original inverter, on/off/reset and circuit bank A/B is of course not taking part in the festivities anymore. I'm nearly certain this would have nothing to do with the problem, but I'm uncertain how FT set that panel up. Guess I better go in there and see if it's supposed to get 120v to complete an important circuit? Seems really unlikely. Again this is an '89 u280 that used to have a 1500w pacs inverter. Any and all help appreciated.

Re: victron multiplus compact install in a U280 install advice

Reply #8 –
The original Pacs was a standalone inverter. There was a standalone converter that charged the house batteries. The new Victron should replace those other two. You don't want all power in and out for the coach through the Victron. You want the battery leads to go to the house batteries. Remove the old converter charger. Pull 120 volts from one leg of the circuit breaker panel to the Victron and from the Victron to a sub panel that powers the 120 volt circuits that you want, usually the microwave and the entertainment center and the 120 receptacles.

Re: victron multiplus compact install in a U280 install advice

Reply #9 –
The standalone converter also died, which was one reason I bought this new thing, so yep that's how we'll run this! 

Re: victron multiplus compact install in a U280 install advice

Reply #10 –
A quick update, I found a solution to the problems I was having with getting the Multiplus compact to do what I wanted it to do. I bought a Multiplus II 2x like I should have in the first place. Everything about this install is performing how I want it to, and it turns out I have a pal rebuilding a small travel trailer that would love to score a deal on the multiplus compact. So that's another item checked off the to-do list! That just leaves the doesn't wanna-run generator, and troubleshooting the unresponsive front furnace...