New Victron Multi 5kVA added to Old Multi 3kVA

[Pelagic]

My new Victron Multiplus 24/5000/120 Invertor charger arrives in Subic next week to support my original 24/3000/70 Multi installed in 2008

I’d like help to Conceptually review my AC Distribution and Re-Wiring plan before finalizing materials and layout for a completely newly wired and fused installation.

• My goal on this retrofit is to use what I already have except for cables,
• Think ahead to switching to Lithium in about 5 years,
• Keep it as simple as possible without changing existing Distribution Panels, as this is an older steel mono hull with limited technical spaces.

The reason I added this new Multi 5kVA is because I now have a surplus of Solar to serve my electric galley and other AC needs for a 230V 30a 50Hz system.

1st photo shows that my original #1 Main AC Board has physical lockouts for SHORE/GEN/INVERTER
2nd Photo shows that this #1 Board has 10 Distribution breakers.
3rd Photo shows that in 2008 I added this #2 Distribution Panel, so that I could turn off any non-preferent AC consumers when on 3kVA Inverter.

In 2008, I opted NOT to use Victron Power Management on shore power and I just wired system as original for a stand-alone Inverter using same physical lockout.

My reason is that shore power in the Philippines is very rare with inconsistent voltages as low as 170V, so I did not want to risk damages to my new Inverter.

Now that I have Solar, this is somewhat academic as my 10Kw Gen is just used for charger backup in poor solar conditions as new Water maker and all other high load motors are now 24v DC.
I doubt if I will use Shore Power any more.

4th photo shows my “AS IS” AC Power Supply and distribution, with many of the labels now repurposed.

5th Photo shows my “Conceptual Plan” which is to make the smaller 3kVA Inverter an “Always On” UPS to the #2 Panel, for small load computer/entertainment electronics and Owner’s Cabin/Office

The New Victron Multi 5kVA which is connected to the “Selectable Main Panel” is for the major AC loads which I will of course need to manage so as to keep my 230V AC loads below 18-20 amps when using 5kVA Inverter.

It will be On most of the time when at anchor or underway, but with the Selectable option.

If on Generator for Charging my House Bank, I do want to be able to provide AC Power to the #2 UPS Panel if desired or simply to be able to power the Multi 3kVA’s 70a as a backup charger.

The 5th Photo shows me using #7 Breaker on New Labels and going to perhaps a “Manual Transfer Switch” to accomplish that….

“Conceptually” does anyone see a problem with this configuration or have other ideas?

Once I get the Conceptual locked in and confirmed installation spaces, I’ll work on the new wiring plan for the other Victron parts I bought.
Thanks for your input

[Pelagic]

1st Photo shows the basic power diagram “as is” now before changes

2nd Photo is the basic 24v DC plan “as is” now before changes.

3rd Photo shows my House battery irregular layout of 6 x 8D AGM’s in series/parallel

4th Photo is part of my new Victron order which is a “Battery Balancer “

Hopefully this will keep the AGM’s better balanced and may even be useful in a future Lithium Bank install.

[arsenelupiga]

i am not electrically educated but my observation is that 100% of boats that i have inspected and have decent inverter, also have elevated corrosion problems.

for this reason i stay away from big inverters. If I had one would connect it only when used else kept it totally off grid.

[CharlieJ]

@arsenelupiga. Post #3.

Since, by your own admission, you are "...not electrically educated..." I will be blunt: there is absolutely no cause and effect relationship between the installation of an inverter, installed in accordance with the manufacture's documentation, and corrosion issues on a boat. None.

[s/v Jedi]

It seems you plan to power the 3kW unit from the output of the 5kW unit. I don’t think that is a good idea.

The attached diagram is the only way I can recommend to do this. Of-course, you only have one shore power input, so only 2 input selections: shore and genset. I use a rotary switch there but you can use what your panel has as well. But eliminate that 3rd option “inverter” and repurpose the breaker position.

The three breakers that come after source selection are crucial and allow options not obvious at first sight. Remember that when an inverter/charger gets AC input, it switches it’s inverter offline and instead starts changing batteries and transfers input power to it’s output. By having these breakers, you can force one unit to invert, even when there is shore power. You may want this to get the frequency right, while the other unit is charging batteries.

Note the bypass breaker and selection on the group source selectors later on. This allows any AC load to run straight from shore power or genset, without any unit in between. This is useful for appliances like A/C or water heater and a life saver in case of inverter/charger failure.

Then the group source selection switches. These enable you to use inverter power instead of available shore power in case the shore power is too dirty or the wrong frequency/voltage while it is good enough to charge batteries using the other inverter/charger. The reason for having multiple groups is to spread load over several sources, i.e. the induction cooktop on one inverter/charger and the convection oven on another.

Switch panels can be adjusted by rewiring. Distribution panels are always in use and all you would need is one or more rotary switches which are easy to add. Note that you don’t need the auto transformer setup as that’s just for US 120/240V 60Hz setup.

[Pelagic]

Originally Posted by s/v Jedi

It seems you plan to power the 3kW unit from the output of the 5kW unit. I don’t think that is a good idea.

Hi Nick, thanks for the quick review as per my pm to you.

I just need to clarify the basic connection if only using the 3kW unit as an Inverter only and not doing Power Management

I thought I just needed to provide an Input Voltage (V DC) from my 24v House Bank to power the Inverter Side which would supply AC only to the #2 UPS distribution panel?

Does the 3kW unit require a constant AC Input Voltage to work, if not using the charger? (Remember, I'm not using Power Management)

If not, then I'm ok as I would never use the 5kW unit to power the 3Kw.

It is only when I have selected either Shore or Gen Supply, that I would provide AC to the 3kW if needed.

[Pelagic]

Diagram shows all the 24v Charging and Monitoring components (Old and New) that I may use.

The new CCGX will display Data from all the new Victron components I bought:

• BWV 712 Smart,
• MPPT Blue Solar 75/15
• 5kW Multi,
• Orion TR Smart DC-DC Converters

I need to study about connecting the CCGX to the older 3kW Multiplus as that will affect how I use the old BMV 600 (Maybe as 12V DC Monitor or 24v Start Batteries)

To make room for new Multi, I will shift my old 24v-50A Victron Skyla Charger down to engine room in case I need to baby old start batteries in the future (Skyla installed in 1992 and this charger still works great!

[Dockhead]

Originally Posted by Pelagic

Hi Nick, thanks for the quick review as per my pm to you.

I just need to clarify the basic connection if only using the 3kW unit as an Inverter only and not doing Power Management

I thought I just needed to provide an Input Voltage (V DC) from my 24v House Bank to power the Inverter Side which would supply AC only to the #2 UPS distribution panel?

Does the 3kW unit require a constant AC Input Voltage to work, if not using the charger? (Remember, I'm not using Power Management)

If not, then I'm ok as I would never use the 5kW unit to power the 3Kw.

It is only when I have selected either Shore or Gen Supply, that I would provide AC to the 3kW if needed.

The Multipluses do not require AC power, to function as an inverter. I would think that this would be obvious from the way they work.


However, if I were you, I would really wire them as intended by Victron and run all your AC power through one of them. You could get the Quattro which has the transfer switch built in, or if you already ordered as a Multiplus, you can buy a solenoid transfer switch.


It's really great being able to limit current taken from your genset, and to use crappy shore power without blowing the breaker. One of the best features of these units; why would you give it up?



My Kohler genset is rated at 6.5kW @ 230v but I derate it to about 85% of that (25 amps vs 29.5 amps) which I'm sure is good for it.


I can use atrocious shore power, even down to 6 amps or even 4 amps (not that rare in France and some parts of the Baltic), happily.


The only downside is that if the unit goes down, you lose all AC power. But that's easily dealt with in a few minutes by temporarily wiring around the unit.

[Singularity]

I have a Magnum 24/4000/110 (MSH4024)...it has what Magnum calls load-assist, where, if on shore/genny power the boat's AC bus asks for more than the shore/genny provides, then the unit will decrease charging and/or draw from the battery to feed to AC demand (clearly this would be a non-sustainable and odd situation, like maybe powering some large compressor). Perhaps this is equivalent to the Quattro or Multipluse with solenoid transfer switch?

Otherwise I'm assuming that a single 5kw inverter is going to meet all the boat's AC needs*. If this were true, I'd suggest:
1) Just exchanging the 5000W for the 3000W unit and let the 5000w unit run the entire boat (minimal to no re-wiring and re-thinking of current electrical configuration)
BUT
2) Wire the old 3000W unit such that it's parallel to the 5000w unit...but is completely isolated from ~everything (via ~emergency switching) such that the 3000w can be brought online in anger, but doing so must first isolate the 5000w unit from ~everything else).

If this makes sense, the old 3000w unit may never be used again (if all remains well with the 5000w unit) and just sits off to the side.

*3,000~5,000W is a heck of a lot of amps to draw from the battery bank, LFP or not, and if drawing that much over any amount of time...then time to run the genny, no?

Horses for courses, but I'd rather just have one expensive, heat-producing inverter box energized in the engine compartment at a given time.

Agreed that a straight "shore to boat AC bus" bypass circuit would be nice to have in place for the rare situation where everything else is somehow offline and shore power is available (straight = including a breaker and ideally isolation transformer between the shore and boat AC bus).

[Pelagic]

Originally Posted by Dockhead

The Multipluses do not require AC power, to function as an inverter. I would think that this would be obvious from the way they work.


However, if I were you, I would really wire them as intended by Victron and run all your AC power through one of them. You could get the Quattro which has the transfer switch built in, or if you already ordered as a Multiplus, you can buy a solenoid transfer switch.


It's really great being able to limit current taken from your genset, and to use crappy shore power without blowing the breaker. One of the best features of these units; why would you give it up?



My Kohler genset is rated at 6.5kW @ 230v but I derate it to about 85% of that (25 amps vs 29.5 amps) which I'm sure is good for it.


I can use atrocious shore power, even down to 6 amps or even 4 amps (not that rare in France and some parts of the Baltic), happily.


The only downside is that if the unit goes down, you lose all AC power. But that's easily dealt with in a few minutes by temporarily wiring around the unit.

Thanks for confirming that I only need DC input Voltage to operate the 3kW Multi as an inverter only.

I think I confused Jedi with my lousy diagrams as to my intent.

You're not the only one to think I'm crazy for not using all the features of the Victron Multi, but in my situation, I really don't need them and wiring as per original is so much easier with all the space constraints I have.

I have not needed my 10kw Generator or shore for charging for 2 years now as with just the two of us, our power consumption is low enough that we will are still.a 30amp AC boat that only uses max 18amps, by turning off non preferents.

If we do end up in PNW for security reasons, then I would change as per Jedi's example, but here in the Philippines, KISS is preferred.

That's why I never ordered the Quattro and since you know I cannot parallel two 3kW Multis from different firmware generations, going with a new 5kW Multi to give me enough reserve of about 16 amps @ 230v AC in tropical conditions (3680W) seemed logical

I only use 6 amps for my hot water tank, so that will be on when I have a surplus of power or motor sailing

My order arrives tomorrow , so I'm committed to use what I have and by keeping the AC Audio/Video/Computer stuff seperate on the 3kW unit, it gives me UPS reliability with those electronics

[s/v Jedi]

Again, I tried and tested many, many configurations and the one I posted is by far the best. It skips all the special features when you don’t need them, but allows their use when you want as well. It has built in redundancy, which is missing from almost all other setups. Last but not least, wiring is easy and any panel can be adapted to this setup.

So no, I don’t think your setup is okay and I don’t see one single advantage to it. You can easily create a good system with minimal wiring modifications.

I also see nothing good in Dockhead’s recommendations. Do not make yourself dependent on a single device. I have experienced failure of inverter/chargers three times and it is not easy to rewire to get back operational. I, with all my knowledge on the subject, managed to kill the residual magnetic field in my genset with such emergency rewiring, which made me push to come to these diagrams that allow emergency operation with the turn of a knob.

[Dockhead]

Originally Posted by s/v Jedi

. . . . Do not make yourself dependent on a single device. I have experienced failure of inverter/chargers three times and it is not easy to rewire to get back operational. I, with all my knowledge on the subject, managed to kill the residual magnetic field in my genset with such emergency rewiring, which made me push to come to these diagrams that allow emergency operation with the turn of a knob.

Certainly it is an advantage to be able to bypass the Multiplus "with the turn of a knob", and when I build my next boat, I will surely set it up just like that.


However, just out of curiosity -- how could you possibly screw up wiring around the unit in case of failure? I am really curious -- you don't have to be an electrical genius for this job. Just pull all the AC wires out of the Multiplus and connect them to each other -- et voila. Even with poor access as I have to my Multiplus, this is a max 10 minute job, and quite idiot-proof. What am I missing?

[Dockhead]

Originally Posted by Pelagic

Thanks for confirming that I only need DC input Voltage to operate the 3kW Multi as an inverter only.

I think I confused Jedi with my lousy diagrams as to my intent.

You're not the only one to think I'm crazy for not using all the features of the Victron Multi, but in my situation, I really don't need them and wiring as per original is so much easier with all the space constraints I have.

I have not needed my 10kw Generator or shore for charging for 2 years now as with just the two of us, our power consumption is low enough that we will are still.a 30amp AC boat that only uses max 18amps, by turning off non preferents.

If we do end up in PNW for security reasons, then I would change as per Jedi's example, but here in the Philippines, KISS is preferred.

That's why I never ordered the Quattro and since you know I cannot parallel two 3kW Multis from different firmware generations, going with a new 5kW Multi to give me enough reserve of about 16 amps @ 230v AC in tropical conditions (3680W) seemed logical

I only use 6 amps for my hot water tank, so that will be on when I have a surplus of power or motor sailing

My order arrives tomorrow , so I'm committed to use what I have and by keeping the AC Audio/Video/Computer stuff seperate on the 3kW unit, it gives me UPS reliability with those electronics

Well if you never even USE the generator, then I guess there is no reason to protect it. I do get the advantage of leaving the wiring alone, even if the system architecture is not optimum.


What kind of A/V and computer stuff do you have running off AC power? I run a 32" screen off AC (which is only used for movies, so not that often), but everything else on my boat is DC. It's not hard to get all your computer stuff, including monitors, on DC power

[Pelagic]

Originally Posted by s/v Jedi

Again, I tried and tested many, many configurations and the one I posted is by far the best. It skips all the special features when you don’t need them, but allows their use when you want as well. It has built in redundancy, which is missing from almost all other setups. Last but not least, wiring is easy and any panel can be adapted to this setup.

So no, I don’t think your setup is okay and I don’t see one single advantage to it. You can easily create a good system with minimal wiring modifications.

I also see nothing good in Dockhead’s recommendations. Do not make yourself dependent on a single device. I have experienced failure of inverter/chargers three times and it is not easy to rewire to get back operational. I, with all my knowledge on the subject, managed to kill the residual magnetic field in my genset with such emergency rewiring, which made me push to come to these diagrams that allow emergency operation with the turn of a knob.

Thanks Nick, I do like your Ver 3 diagram and I will include it in my review with Ocean Gecko Electrical Supervisor to see if he can explain it in detail to me and how he would apply it to my 2 Distribution Panels and 2 Multi Units, with the space and materials available.

He just finished doing a complete electrical refit of a 49m Feadship to class, so I will listen to his preference

If possible, could you send me a link to the Source Select Switch you used?

The one thing that scares me about using Power Management here in the Philippines, is the huge fluxuations on Shore Power Voltage.

It is supposed to be 220v 60 cycles, but I can see it vary hourly from 165V to 210v on a good day, here in Subic.

They blow Transformers constantly and the new Inverter type split Air cons always have problems because of this Voltage issue

If the lack of amps was just the problem as Dockhead experiences, then the Power Management is great.
But if you are fluctuating in and out of Victron's minimum AC Input Voltage Range of 187 V then eventually bad things will happen.

Not rushing to get this done, till I have all the answers.

[Pelagic]

Originally Posted by Dockhead

Well if you never even USE the generator, then I guess there is no reason to protect it. I do get the advantage of leaving the wiring alone, even if the system architecture is not optimum.


What kind of A/V and computer stuff do you have running off AC power? I run a 32" screen off AC (which is only used for movies, so not that often), but everything else on my boat is DC. It's not hard to get all your computer stuff, including monitors, on DC power

In our Bedroom, we have a 40" Samsung Smart TV, Bose sound system and various Game and CD players. My office back there has Scanner/Printer and old Laptops.

We also power a small air cooled Inverter window type aircon, that is built in and Vents out the Lazarette. (Only takes 1-2 amps) We use that a lot when in Drydock or if we cannot vent cabins because of shipyard dust

Pilothouse has an Intel NUC and Samsung Monitor as our Ships' Computer and Nav Station linked to the Cockpit Furuno MFD

Super fast, this is what I wanted to have on a UPS circuit, using the old 3kW Multi, or another option is the original Prosine 1800W inverter.