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Install Victron MultiPlus-II

I thought this was a worthwhile overview of , or review of installing, a Victron MultiPlus-II.
https://youtu.be/mcvD6TVPvA4

This is from another installation.
https://youtu.be/kBYgkN1_r8Y
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"Don't criticize what you can't understand" Bob Dylan

Re: Install Victron MultiPlus-II

Reply #1 –
I have one of these Multiplus II inverters and will do the wiring modifications required to install it this summer to take advantage of its full capabilities.

The Multiplus II requires about 30.5" of vertical space to install it leaving cooling and access space required.  In my coach the vertical height of the bays is 30".  I think a half-inch loss at the bottom will be OK for the wiring connections and cooling needed.  Space at the top should not be less than the minimum required. Neither of these videos talked about the minimum installation requirements.

4.1. Location
The product must be installed in a dry and well-ventilated area, as close as possible to the batteries. There should be a clear space of at least 10 cm around the appliance for cooling.

And the Multiplus II or any other inverter should never be installed in the same space as lead acid batteries.  The videos do not respect this explicit requirement.

WARNING – RISK OF EXPLOSIVE GASES) WORKING IN VICINITY OF A LEAD-ACID BATTERY IS DANGEROUS. BATTERIES GENERATE EXPLOSIVE GASES DURING NORMAL BATTERY OPERATION. FOR THIS REASON, IT IS OF UTMOST IMPORTANCE THAT EACH TIME BEFORE SERVICING THE UNIT IN THE VICINITY OF THE BATTERY, YOU READ THIS MANUAL AND FOLLOW THE INSTRUCTIONS EXACTLY.

Using with Lithium chemistry batteries may be different. It is not specifically addressed in the documentation.

And unless your coach has been modified the 120v wiring to and from the inverter is significantly undersized to use the full capabilities of the Multiplus II (and many other modern inverters) especially on the hybrid output side. (50 amp pass through plus 14 amp from the inverter). This requires wiring bigger than the first video mentioned.  And you should have a breaker box with a 65 amp breaker close to the inverter on the output line.

And space for these significantly bigger wires is hard to come by.  You will have to be inventive to find room to provide a protected cableway.  Every coach will be unique. A basic wiring diagram doesn't tell you how to do it.

Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Install Victron MultiPlus-II

Reply #2 –
Quote from: Roger & Susan in Home2 –

And unless your coach has been modified the 120v wiring to and from the inverter is significantly undersized to use the full capabilities of the Multiplus II (and many other modern inverters) especially on the hybrid output side. (50 amp pass through plus 14 amp from the inverter). This requires wiring bigger than the first video mentioned.  And you should have a breaker box with a 65 amp breaker close to the inverter on the output line.

Roger

Roger, Is that also true of the Multiplus 3000?  Our install was done with an the AM Solar Smart Phase and the Multiplus.  We've had some issue with an Error 24 (Overload) when switching shore power/gen power on and generator power off.  We need to shut down the inverter prior to connecting or disconnecting.  Once the transfer switch engages, we can flip the invert back on and all is well.

My solar installer thinks it may be the original wiring in old and needs replaced or there is some other condition causing an abnormal voltage drop.  (Its not something we were seeing when we first installed it.)  Replaced the transfer switch and swapped out the inverter for a replacement, but still no joy.  I'm hoping to catch up with him this spring to troubleshoot, but youd comment caught my eye.

Joe

Very happy with our install other than that
Joe Phebus and Jaime Trujillo
2002 U270 3410  Build: 5953 Motorcader # 18595
2100 W Solar, 600 AH Battleborn Batteries,  Victron Multi-Plus II 3000 Inverter, Cerbo GX, & MPPT Chargers
1992 Geo Tracker

Re: Install Victron MultiPlus-II

Reply #3 –
Joe, the original wiring is most likely 12ga romex both ways.  The inverter circuit has a 20 amp circuit breaker as originally wired so that limits power to the inverter to 20 amps and from the inverter to about 20 amps (~2400 watts).

I am not sure where you are seeing the error code, probably the multiplus.  The AM Solar Smart Phase has reported problems especially with the early version, I have heard. I had one on order and they sent me an email suggesting I abandon that way and use the new Multiplus II instead. There was a pretty good deal on them earlier in November so I thought I would try it out.

I would be surprised if it is a wire problem. If it is wiring it is more likely wire connections at either end or perhaps a circuit breaker.  If you have an in-lb torque wrench set them to whatever they are supposed to be (maybe 10 in-lbs) or just make sure all the connections are tight. 

Double-check your 12 v connections as well.

I would give AM Solar a call and ask them about the error code.  It wasn't happening before the changes and for a while after. The Inverter and the transfer switch were replaced and the error is still there.  The only thing not changed is the AM Solar device.

Usually when a transfer switch does what they do there is a clean break between one side and the other. 

Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Install Victron MultiPlus-II

Reply #4 –
Quote from: Roger & Susan in Home2 –
Joe, the original wiring is most likely 12ga romex both ways.  The inverter circuit has a 20 amp circuit breaker as originally wired so that limits power to the inverter to 20 amps and from the inverter to about 20 amps (~2400 watts).

I am not sure where you are seeing the error code, probably the multiplus.  The AM Solar Smart Phase has reported problems especially with the early version, I have heard. I had one on order and they sent me an email suggesting I abandon that way and use the new Multiplus II instead. There was a pretty good deal on them earlier in November so I thought I would try it out.

I would be surprised if it is a wire problem. If it is wiring it is more likely wire connections at either end or perhaps a circuit breaker.  If you have an in-lb torque wrench set them to whatever they are supposed to be (maybe 10 in-lbs) or just make sure all the connections are tight. 

Double-check your 12 v connections as well.

I would give AM Solar a call and ask them about the error code.  It wasn't happening before the changes and for a while after. The Inverter and the transfer switch were replaced and the error is still there.  The only thing not changed is the AM Solar device.

Usually when a transfer switch does what they do there is a clean break between one side and the other. 

Roger

Thanks, Roger

Yep... error is coming from the Multiplus.  I'll give a call to AM Solar as you suggested.  They swapped out the Multiplus after we got the original error.  No mention of issues with the Smart Phase switch, but I agree, that seems the most likely culprit.

Are you happy with the Multiplus II?  Maybe I should think about a trade out if that's the better way to go.

Joe

 
Joe Phebus and Jaime Trujillo
2002 U270 3410  Build: 5953 Motorcader # 18595
2100 W Solar, 600 AH Battleborn Batteries,  Victron Multi-Plus II 3000 Inverter, Cerbo GX, & MPPT Chargers
1992 Geo Tracker

Re: Install Victron MultiPlus-II

Reply #5 –
I haven't installed the Multiplus II yet, it came after we left for the winter. It is a good thing, it gives me time to consider all options, back away and come at it from different way. Usually this gets me a better result. I have very limited opportunities in which to fit the Multiplus II and leave the required clearances.

I have to figure out how and where to run the bigger 120v cables. I have a pretty good idea how to do it.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Install Victron MultiPlus-II

Reply #6 –
Quote from: Roger & Susan in Home2 –
I haven't installed the Multiplus II yet, it came after we left for the winter. It is a good thing, it gives me time to consider all options, back away and come at it from different way. Usually this gets me a better result. I have very limited opportunities in which to fit the Multiplus II and leave the required clearances.

I have to figure out how and where to run the bigger 120v cables. I have a pretty good idea how to do it.

Thanks, Roger.  AM Solar is working with my solar installer on troubleshooting.  Confirmed that he used the AM Solar Kit, and replaced all the inverter wiring and used 6 awg AC wiring, so that's the good news.

I'm learning what I can from you all so  I can help with troubleshooting and speaking half-way knowledgably with them.  I'm curious about this in your original post.  "And you should have a breaker box with a 65 amp breaker close to the inverter on the output line. "  If its 50 amp service, why would the breaker be > 50 amps?  I would have expected a 50 amp breaker as the max.  Not trying to second guess, just trying to learn what I can in case I end up going the Multiplus II route.

Thanks,

Joe
Joe Phebus and Jaime Trujillo
2002 U270 3410  Build: 5953 Motorcader # 18595
2100 W Solar, 600 AH Battleborn Batteries,  Victron Multi-Plus II 3000 Inverter, Cerbo GX, & MPPT Chargers
1992 Geo Tracker
 

Re: Install Victron MultiPlus-II

Reply #7 –
This is actually understated a bit for the Multiplus II.

If you are plugged into 50 amps and the inverter is passing through 50 amps and the inverter senses that the load is greater than 50 amps then it will reduce charging or stop charging and start inverting and adding additional amps.  It can be up to an additional 25 amps with the Multiplus II.

" AC-out-1
The AC output cable can be connected directly to the terminal block 'AC-out'. From left to right: "N" (neutral) , "L2" (phase 2), "PE" (earth) and "L1" (phase 1)
With its PowerAssist feature the Multi can add up to 3kVA (that is 3000 / 120 = 25A) to the output L1 during periods of peak power requirement. Together with a maximum input current of 50A this means that the output can supply up to 50 + 25 = 75 A. An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in series with the output, and cable cross-section must be sized accordingly. Victron Energy recommends to use the Blue Sea systems GFCI circuit breakersPN. 309X or 310X. The maximum rating of the fuse or circuit breaker is 75A."


For this amount of current on the output side you probably need 4 ga x3 plus a ground cable.

So the 50 amps passing through plus another 25 amps gets you into that 75 amp range.  The idea behind a circuit breaker box next to the inverter with a circuit breaker is to protect the line from the inverter back to the coach distribution panel.

Your incoming line from the post has a circuit breaker at the post and then a main at the box and a breaker for every circuit including the one to the inverter/charger.  Since the inverter is a source, a beaker there makes sense.

 
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN