Wiring critique…

[CharmCityBoater]

Re-wiring my Hans Christian 43T. Would love some critique of my first pass at a wiring diagram…. I do plan to use Victron and will incorporate the Cerbo GX for comms to all hardware.

Critique away!

[goboatingnow]

I presume the batteries have fully internal BMS systems ?

I would suggest that most fuses under 80A could be replaced by resettable circuit breakers , fuses are a pain to replace quickly and blowing one on your windlass for example can cause panic stations

[flee27]

Not knowing the lengths can't say for sure but some of your wire sizes seem excessive. Not that it is a problem to have too large of a gauge wire. Only more costly and harder to run if not needed.

I agree with the circuits breaker recommendation from gobatingnow for the reason stated and also I trip my windlass breaker when not using the windlass. I have seen switches fail and the windlass run dropping chain or pulling against a already raised anchor unexpectedly.

I would also want a cut off on my inverter. I would be useful to disconnect the inverter without losing your DC system to the rest of the boat.

I am currently diving down the same path on my boat so am interested in the feed back also.

Good luck.
Foster

[tkeithlu]

Why is the AC panel fed by the inverter, rather than directly from the isolation transformer?

Do you have a way in mind to parallel the house battery and the starter battery?

Do you anticipate a genset, or another source than solar, when off shore power?

What happens when your house batteries are flooded with seawater? Can you arrange a backup battery to power your radio?

[team karst]

per post #4, the 3kW invertor won't fully power a 30A 120V panel. Traditionally, a rotary switch selects invertor vs shore power on a subset of the 120V loads.
The ELCI at shore power is a breaker on both legs, not a fuse, as shown. btw, the IEC symbol for a circuit breaker is like what you show for a switch, but has a little X for the NO/fixed contact.
The 8/3 AWG 120V lines can be 10/3 on that size boat.
Does the dc to dc charger allow charging of the house from the alt? Basically, I can't tell the power direction flow related.
The comment on the emergency 12V feed to the VHF is a good one; In the past, I've had two VHF,s but fed from different battery sources, including a start battery. otoh, a good HH counts, and a bonus if you have a ext antenna provision.

[CharlieJ]

It looks like you are off to a good start; however, the good folks at Victron have developed a whole series of schematics...why re-invent the wheel?

Here is the link: Victron System Schematics

[CharlieJ]

#4 and #5: Modern inverter/chargers, like the Victron, are designed with the ability to pass through mains power (shore or gen) and stay in synch with the incoming power so that when mains power is lost, there is a very quick (<20mSec) transfer to the inverter.

This is done with an auto bus transfer switch (ABT) that is internal to the I/C. A modern I/C also has a Power Assist feature where the I/C will assist the mains should the load momentarily exceed the mains capacity.

All of this is internal to the Victron Multi or Quattro. No source selector switch is required or desired if these features are going to be used.

[Time2Go]

A quick glance from a non-engineer

1. You need an inverter cut off switch for the 12 volt positive to the inverter.
If your inverter is an on demand type an outlet might seem dead to a meter
with no load but will come alive with a load. You need a way to be 100%
sure it's not going to output AC

2. Your "unswitched DC fuse" block is indeed switched by the battery switch
You pull up to the dock switch the batteries to off and there goes your bilge pumps
I'd hard wire, fused, directly to the battery

3. Alternator cut off switch for 12v Positive
So, if you have to work on the engine a dropped wrench cant cause a short

There are some really good online resources
Check out the videos and diagrams by Pacific Yacht Systems
and pick up a copy of Charlie Wing's
Boatowners Illustrated Electrical Handbook

Cheers
Neil

[goboatingnow]

Several other things done of which might have been mentioned

1. You need a positive un switched dc bus wired directly to the battery, ie before the marked battery switch ( but still protected by the internal battery bms disconnect ) this bus powers up anything that needs permanent 12v

Secondly your alternator should feed directly to the battery not via the switch as inadvertently switching that switch with the engine running can blow the alternator.

[Ween]

the Victron 3000 inverter spec is 4/0 or 2 x 1/0 so you are a bit light on your main 12V wiring. They provide 2 posts for each + and - since they know working with 4/0 isn't fun.

And ditto on ALT isolator and Inverter Isolator and separate un-switched bus for bilge pumps etc.

[smac999]

Move house battery switch to between pos bus and house panel.

Inverter needs own battery switch between bus and inverter.

Solar, dc to dc and bilges should not be switched.

Which way is the dc to dc going?

That battery switch can stay but it should be hidden and never turned off unless a specific reason by someone who knows why.


The 3000w victron probably wants a 400a fuse. Abd 4/0.

What is the 4awg for? The trickle charger? That seems way to big. You can’t connect that it’s too big. 12 or 10awg would be max. It’s probably only a few amps.

[smac999]

Originally Posted by team karst

per post #4, the 3kW invertor won't fully power a 30A 120V panel. Traditionally, a rotary switch selects invertor vs shore power on a subset of the 120V loads.
The ELCI at shore power is a breaker on both legs, not a fuse, as shown. btw, the IEC symbol for a circuit breaker is like what you show for a switch, but has a little X for the NO/fixed contact.
The 8/3 AWG 120V lines can be 10/3 on that size boat.
Does the dc to dc charger allow charging of the house from the alt? Basically, I can't tell the power direction flow related.
The comment on the emergency 12V feed to the VHF is a good one; In the past, I've had two VHF,s but fed from different battery sources, including a start battery. otoh, a good HH counts, and a bonus if you have a ext antenna provision.

The 3000w victron will have dual 50a or 100a passthrough. It also has 2 outputs to split inverter and non inverter loads. So you can run 2 wires from the inverter to panel if you don’t want to invert the whole panel. I would move Hwt etc off inverter. All current should go through the inverter as shown so the boosting and charge clawback work correctly. Rotary switches for inverters were from 30 years ago. Nobody does that now.

You will want main breakers atleast before and probably after the isotransformer

[Wotname]

Originally Posted by smac999

Move house battery switch to between pos bus and house panel.

Inverter needs own battery switch between bus and inverter.

Solar, dc to dc and bilges should not be switched.

Which way is the dc to dc going?

That battery switch can stay but it should be hidden and never turned off unless a specific reason by someone who knows why.


The 3000w victron probably wants a 400a fuse. Abd 4/0.

What is the 4awg for? The trickle charger? That seems way to big. You can’t connect that it’s too big. 12 or 10awg would be max. It’s probably only a few amps.

The red bit is the best sentence I have read for a long time .

The emphasised section could become my goto phrase for 2022!