New Victron Multiplus install with Li Batteries

[MerMike]

If I read this correctly, you'll be using 3 Orions to charge the bank from the alternator. A total of 90A charging for a 400A bank seems low at .2C. You're not using anywhere near the full output of your 170A alternator, which is good for the alternator, but I think you're going to be disappointed with the charging performance.

How will you handle a low voltage disconnect? The BB's will just shut off taking everything offline. You might consider an emergency parallel switch to energize critical loads with the start battery.

You need a separate case ground from the Multiplus to the AC ground bus if you want to be ABYC compliant.

Originally Posted by scfoster

Took another stab at the electrical diagram, beginning with a Victron schematic and modifying to come close to what I'm going to do. I'll have 3 DC-DC chargers and the CERBO GC wiring isn't correct.
After reading the Multiplus manual, going to add another 100Ah battery to bring to 400Ah total.
Looking for input on overall design, as well as fusing, breakers and switches.

[scfoster]

Originally Posted by MerMike

If I read this correctly, you'll be using 3 Orions to charge the bank from the alternator. A total of 90A charging for a 400A bank seems low at .2C. You're not using anywhere near the full output of your 170A alternator, which is good for the alternator, but I think you're going to be disappointed with the charging performance.

Your statement makes sense. For my current needs, it's not an issue for me. Being berthed in a marina on the Chesapeake and going out for 2-3 day sails, with shore power available at pretty much all times when not sailing, I'm not really relying on a full charge from the alternator.

The intent is to replenish whatever is used with the windlass and bow thruster.
Adding 300W of solar to the mix as well. Plan on seeing how much juice I actually get from the solar. Can add another 150W panel if needed. Can also add another Orion or go with another more direct charging solution.

The reason for the 170A alternator is a 'one and done' approach. I don't want to have to mess with it again for quite a few years. Had to upgrade the old Balmar so went as large as possible. Discussed the pros and cons at length with Peter Kennedy at PKYS.com (yes he answers the phone). He talked me out of a 220A alternator, so no upselling involved.

How will you handle a low voltage disconnect? The BB's will just shut off taking everything offline.

The alternator is wired directly to the engine start battery, so that acts as the 'spring' to absorb what would otherwise be a bad spike. The Balmar MC-614 regulator isn't shown in the diagram.

You need a separate case ground from the Multiplus to the AC ground bus if you want to be ABYC compliant.

The green case ground wire is shown in the pdf diagram, on the negative busbar just above the shunt.

The plan is to wire everything up at home on a hot bench, with cable lengths either exact or with some extra play for installation. A lot easier to do on a sheet of plywood standing upright, than doing the contortionist trick with bad lighting.

I do appreciate everyone's comments. Please keep them coming.

[MerMike]

I'd also recommend a galvanic isolator on the AC shore power input, if you haven't considered it already. You main breaker should be an ELCI within 10' of the shorepower inlet.

[MerMike]

I mentioned it because the DC case ground doesn't fulfill the requirement. It's exactly as I said, a separate AC case ground is required. I've even argued this with Mike Bonicker at ABYC. The reasoning is that the AC case ground provides a more direct path to ground than through the DC bus bar.

"We want as direct a path as possible for the fault current to get back to its source. We don’t want AC current to have to go through additional connections at the DC bus to get to the AC bus and we don’t want DC current (especially the levels we have potential for with inverters) to have to go through an AC bus or especially AC wiring which is likely going to be too small (very rare to have 1/0 or 2/0 cable in the AC system, even between the busses). Remember, current only wants to go to earth ground when earth ground is a path back to the source."

Originally Posted by scfoster

The green case ground wire is shown in the pdf diagram, on the negative busbar just above the shunt.

[MerMike]

Originally Posted by scfoster

The alternator is wired directly to the engine start battery, so that acts as the 'spring' to absorb what would otherwise be a bad spike.

Does that mean your start battery is connected at all times and thus is being charged by all of your charge sources? If your charging system is set for LiFePO4 and it's charging an AGM battery, I think the AGM would soon croak.

Edit: Never mind, figured out the logic. It appears that the start battery is constantly energizing the DC bus. You might want some sort of LVD device on the start battery to keep it from draining entirely.

[scfoster]

Originally Posted by MerMike

I'd also recommend a galvanic isolator on the AC shore power input, if you haven't considered it already. You main breaker should be an ELCI within 10' of the shorepower inlet.

Purple note between shore power and MCB "ISOLATION TRANSFORMER OR GALVANIC ISOLATOR SHOULD BE INSERTED HERE IF NEEDED. INCLUDING NECESSARY BREAKERS."

Boat currently has two 30A shore power connections with Galvanic Isolators on each.

Earlier post I stated I'm going to update the powerpoint to show the actual components in detail. Diagram now only shows the MCB but as you point out, should have the ELCI or RCB shown as well. ESPECIALLY since the water at the home marina is brackish, bordering on fresh water.

Thanks for pointing out.

[scfoster]

Originally Posted by MerMike

Does that mean your start battery is connected at all times and thus is being charged by all of your charge sources? If your charging system is set for LiFePO4 and it's charging an AGM battery, I think the AGM would soon croak.

Edit: Never mind, figured out the logic.

Not to worry... spend half my time on conference calls thinking "why oh why did I sleep through those EE classes?"
I thought all you had to do was keep the smoke in the wire and all good (Jaguar electrical manual).

[MerMike]

Originally Posted by scfoster

Purple note between shore power and MCB "ISOLATION TRANSFORMER OR GALVANIC ISOLATOR SHOULD BE INSERTED HERE IF NEEDED. INCLUDING NECESSARY BREAKERS."

Haha, I didn't couldn't read the fine print!

[MerMike]

Originally Posted by scfoster

Not to worry... spend half my time on conference calls thinking "why oh why did I sleep through those EE classes?"
I thought all you had to do was keep the smoke in the wire and all good (Jaguar electrical manual).

Found some for you.

[MerMike]

BTW, nice wiring diagrams.

[MerMike]

Originally Posted by scfoster

The plan is to wire everything up at home on a hot bench, with cable lengths either exact or with some extra play for installation. A lot easier to do on a sheet of plywood standing upright, than doing the contortionist trick with bad lighting.

This is a good approach. Be as thorough as you can on the bench. Even so, there will be surprises. I had to remake a couple of the shorter 2/0 cables, but was able to repurpose them elsewhere.

[DeValency]

Originally Posted by scfoster

Not to worry... spend half my time on conference calls thinking "why oh why did I sleep through those EE classes?"
I thought all you had to do was keep the smoke in the wire and all good (Jaguar electrical manual).

Impressive work by the eyes of an EE here... 👍🏻 never enough learning from real life experience. Especially as I’m more or less doing the same project myself.

For mow, decided to keep the 400A AGMs as long as they’re alive - these were replaced two years ago when the cost of LFP was twice... it also helps in managing a safe alternator charging to the LFPS...

Need to experience and compare the real life with adding 400A LFP now before removing the AGM.

While most of my electrical is Victron based (quite obvious for a Dutch built boat), which I really admire, wish Victron BMS could also be used on non Victron batteries. The other BMSs available are the only devices I still can’t be 100% happy with - we still need a better solution for a boat BMS.

[DeValency]

Yes, my first round of bench building and testing was on a cheap 100A assembly at my kitchen....
Now followed by the real components- still to be tested in the kitchen. Sorry for the pic orientation. I’m tired in fighting the stupid way the website handle attachments and pics.

[MerMike]

I had a really tight space to work in and was very difficult to do any detailed work once installed. I built a mockup of the bay out of floor underlayment, 'cause I had some around. Once I had the final position for everything I mounted it all to marine ply for the final install. I used T-nuts in the plywood and threaded screws/bolts to attach the equipment so it can be removed and reinstalled repeatedly. Pulled the gear, painted the plywood, reinstalled the gear, then installed the plywood panels and made the connections.

[scfoster]

Originally Posted by MerMike

I'd also recommend a galvanic isolator on the AC shore power input, if you haven't considered it already. You main breaker should be an ELCI within 10' of the shorepower inlet.

MerMike, have been doing the research on the ELCI requirement. I will admit I did not realize this was an ABYC requirement for new boats. Again, not an electrical expert so trying to figure this out.

Here is a link to the BlueSea page discussing the ELCI.

ABYC regulation E–13.3.5 states:
If installed in a head, galley, machinery space, or on a weather deck, the receptacle shall be protected by a Type A (nominal 5 milliamperes) Ground Fault Circuit Interrupter (GFCI).

ABYC regulation E–11.11.1 states:
An Equipment Leakage Circuit Interrupter (ELCI) shall be installed with or in addition to the main shore power disconnect circuit breaker(s) or at the additional overcurrent protection as required by E–11.10.2.8.3 whichever is closer to the shore power connection.

My boat has two 30A shore power inlets. One is for the Air Conditioning system ("AirCon") and the other is for everything else. Each currently has a Guest 2433P Galvanic Isolator.

Had toyed with going to a single 50A shore power inlet as the pedestal at the home marina is 50A. But, now I'm being moved to another slip that has a single 30A with a 'regular' GFCI outlet. The Victron Multiplus has an AC input circuit that splits to two AC outputs. #1 does not interrupt if shore power is disconnected, switching to the inverter. #2 shuts down if shore power is disconnected, which is the branch to which the AirCon would be connected. The Multiplus has a feature where it will draw from the House Battery bank in the case of a current draw that would otherwise overwhelm the 30A breaker. So if the water heater is on and the AirCon (16,000 BTU 34A startup 15A max continuous) starts up, the house battery bank will take up the slack until the initial startup draw decreases.

Think I'm going to keep the two 30A shore power inlets, along with the Galvanic Isolators. Going to put a switch (BlueSea 1481) in to allow for the AirCon to be powered either from the Shore #1 connection through the Victron Multiplus. When a second 30A shore power connection is available, I can use that and flip the switch so the AirCon is on it's own separate circuit, separate from the Victron Multiplus.

Now I have a dilemma. Where to put the switch and the ELCI's? I think I'm lucky with the port lazarette forward bulkhead (aft wall of the galley) is 9 feet from the shore power plugs, which is a straight shot to run the cables. So to keep it cheap, I may move the entire AC panel to that bulkhead, with access from the galley wall. Since it's along the current cable run anyway, shouldn't have to run any additional cables. Was going to have to move the current OEM AC panel as the Victron Multiplus is going in that space under the chart table.

Anchor Express has the BlueSea 3102100 ELCI breakers for $113each.

Thoughts?