AC / DC Line Diagram ( Partial, Mostly )

[s/v Jedi]

Originally Posted by goboatingnow

With protection from the transformer and the RCBOs I would not advise any connection between DC negative and protective earth.

fully agree; lots of potential problems are blocked by keeping these separate.

The other thing is the electrical system assumes that the inverter AC output doesn't have anything in common with the shorepower you could need common power feeds to devices that you want to run either from the inverter or shorepower. That's requires a different configuration

Exactly and I have a hard time believing that Extemp would want it like it's drawn. The only reason for this setup would be that the inverter/charger has no transfer switch, in which case you can add an external transfer switch. I can't imagine the inverter/charger not having a transfer switch?! Is it an old unit?

The battery switches are fine but since the whole diagram is non standard drawings it's all a bit confusing.

Okay, I think the diagram shows the back-sides of the three switches? With copper bars interconnecting them... But does that present a physical setup? Normally the starter battery and engine are in a different location than the house batteries and their main bus bar. I guess they are in close proximity in this case. Anyway, do not create long cables in starter circuits to accommodate switches in a nice position... keep those cables as short as possible and compromise on switch position if needed.

cheers,
Nick.

[Mark Johnson]

I am a firm believer in simplification. What we did is:

Install a large house bank, (>10 year lifespan)... and a very small $60 engine battery, which is not meant to last but a few years.

We have two three way selector switches. One selects which bank to crank the engine with, and the other selects which bank to run the boat on. Both switches have been used in the same positions for 15 years. (Eng. bat. switch to the eng, and house bat. switch to run the "house"). They were only installed as "worst case" options, and we've never needed them.

The solar panels, dockside charger, and alternator, ALL GO TO THE HOUSE BANK... ONLY!

(Yes, the alternator should ideally have it's neg. wire go directly to the alternator, AND have a "Zap Stop".) This is as opposed to just any engine bolt.

The house bank is paralleled to the eng. battery with a "blue Sea" battery combiner. With this, the engine battery gets the few amps that it needs after cranking the engine, from the alternator bringing the house bank's line v above 13v, then the combiner "combines", and the banks are paralleled. (The eng. battery will be charged in about 15 minutes).

As soon as all charging sources are off, and you are running on the house bank, the line v goes below 13v and the "combiner" disconnects the two banks. This way there is no way to accidentally discharge the engine battery, by running the boat.

You run EVERYTHING on the house bank, and need only one "Link 10" shunt, sensor wires, etc.

Since the engine battery is never really used, except to crank the engine, It is always pretty much full, and a simple v meter should let you know if there is a problem.

With the "Link 10" you know exactly the amps in, amps out, line v, and a/h in or out, of the house bank. This is the only one that requires this much information.

If your house bank went flat, the small engine battery COULD be manually switched to run the boat momentarily, but it makes more sense to me to use that eng. batteries' juice to crank the engine, thereby charging BOTH banks.

It sounds like you are trying to have too many bases covered with redundant capabilities, above and beyond what is likely to be needed, at the expense of simplicity.

To keep your ass covered, have an energy efficient boat, and "house" battery bank that can run it for several days by itself. We only cycle ours down to 95% or 85% FULL, every day, before total recharge. It would take a major brain fart lasting several days, for our house bank to go flat.

These systems are perhaps the most vulnerable on the boat.. simplify! IMO...

Mark

[Extemporaneous]

Originally Posted by goboatingnow

Wow , confusion
The battery switches are fine but since the whole diagram is non standard drawings it's all a bit confusing.

Dave

Okay, I've redone the drawing and I think?? it looks much better. Let me know what you think.

Originally Posted by Pete7

Extemp, why do you need a 215 amp starting battery to start a 46 hp engine?

I don't really. My thought is that because my House Battery Bank is in the Bilge, I want to have some capacity above that. My Engine starting battery is about 2 feet higher. With the 215 Amps I could run my boat if I had to. I may?? rotate it into the House Battery Bank as it is the same as the 4 that are in the House Bank. Kind of Doubt it, but perhaps.

Originally Posted by Mark Johnson

I am a firm believer in simplification. The solar panels, dockside charger, and alternator, ALL GO TO THE HOUSE BANK... ONLY!

(Yes, the alternator should ideally have it's neg. wire go directly to the alternator, AND have a "Zap Stop".) This is as opposed to just any engine bolt.

You run EVERYTHING on the house bank, and need only one "Link 10" shunt, sensor wires, etc.
Mark

Mark, I agree with all that you have said, even that I only "need" the Link 10. I'm trying to ascertain what the problem might be by having 2 monitor systems? What are the negatives or even possible negatives?

Originally Posted by Mark Johnson

It sounds like you are trying to have too many bases covered with redundant capabilities, above and beyond what is likely to be needed, at the expense of simplicity.
Mark

I'm certainly trying to cover all I can but I understand your comment regarding simplicity.

Thanks for your comments so far everyone.

Have a look at the Revised Drawing and let me know what you think.

[Heart of Gold]

Originally Posted by Extemporaneous

Well it's been in my head for sometime now, but as I'm finally going to be starting (soon ), I thought it would be a good idea to put pen to paper (so to speak).
That said, I'm hoping that a few of you would comment/rip it apart (at least what is laid out).
It's obviously important that I get this right!

If you would........

Thanks and Best Regards,
Extemp.

Your missing your galvanic isolator in the shore power ground connection to batt negative.

[downunder]

Perhaps same size as house bank batteries.

[Extemporaneous]

Originally Posted by Heart of Gold

Your missing your galvanic isolator in the shore power ground connection to batt negative.

Thanks, but one is not required if you have an Isolation Transformer.

Thanks,
Extemp.

[goboatingnow]

What you have described is a very standard setup. ( Its just drawn a bit odd). Most boats are wired like that. The main difference is the use of a "echo charger" to deal with the starter battery. This is a much better system then either diode splitters or relay combiner, all of which have design defects.

Again the invertor circuit is curious. Normally you will have AC comsumers that you want to work from both shorepower or invertor. ( for example outlets, TV, etc). For this you have two choices, either an invertor with a changeover circuit internal, and hence the invertor powers up the whole "shorepower" AC circuit, or as I did, I have a bank of contactors and I selectively switch over certain AC consumers. This avoids, case of ( in a seperate invertor) trying to charge the batteries with the invertor!, or running the water heater etc.

PS, redo the battery switch diagram , with simple electrical switch symbols, that will read better

Dave

Dave

[DeepFrz]

I will elaborate a bit on my comment on your return line from the alternator to the ground bus. You can run a cable directly from the alternator to the main ground bus, which is the preferred way. It looks like you have the return run through your alternator mounting, through the engine block, to the return line at the starter, back to the ground bus. The main ground bus should not be your engine block, but a dedicated bus. You don't want the return current running through the engine block in any way. It should only run in electrical cable. If it is wired correctly you wouldn't need to show your engine block in the wiring diagram.

[goboatingnow]

Deep Frz is right , in fact if I had teh chance again, I'd go for isolated engine block, with isolated starter and alternator.

Dave

[Mark Johnson]

Originally Posted by goboatingnow

Deep Frz is right , in fact if I had teh chance again, I'd go for isolated engine block, with isolated starter and alternator.

Dave

The easy way to do it is put an on / off switch in the Neg. line feeding the engine, which already has one in the + line. During the 99.9% of the time not motoring, I shut off both. It makes zincs last longer, and is a deterrent to boat theft as well, IF the neg. switch is in a hidden spot.

M.

[Extemporaneous]

Thanks Dave,

In terms of AC consumers that I want the potential to have availible at all times (like you say, the outlets, TV, etc.), they will tie into the "Inverter Elect. Panel" (top right of the diagram). Those luxuries (i.e. electric hot water, additional battery chargers, AC, ect.) that will only be available when hooked to Shore power and may cause problems if hooked to the Inverter, will tie into the "Main Elect. Panel" (top row, 4th from the right in the Diagram). This is the only way that I new how to get this functionality/separation. I am now curious about the details of how you are doing this. Can you explain more along with what equipment you used. Thanks.

Originally Posted by goboatingnow

Again the invertor circuit is curious. Normally you will have AC comsumers that you want to work from both shorepower or invertor. ( for example outlets, TV, etc). For this you have two choices, either an invertor with a changeover circuit internal, and hence the invertor powers up the whole "shorepower" AC circuit, or as I did, I have a bank of contactors and I selectively switch over certain AC consumers. This avoids, case of ( in a seperate invertor) trying to charge the batteries with the invertor!, or running the water heater etc.

PS, redo the battery switch diagram , with simple electrical switch symbols, that will read better

Dave

Duly noted.
I'll change to the proper symbols for the switches.

Best Regards,
Extemp.

[goboatingnow]

Those luxuries (i.e. electric hot water, additional battery chargers, AC, ect.) that will only be available when hooked to Shore power and may cause problems if hooked to the Inverter, will tie into the "Main Elect. Panel" (top row, 4th from the right in the Diagram). This is the only way that I new how to get this functionality/separation. I am now curious about the details of how you are doing this. Can you explain more along with what equipment you used. Thanks.

Your idea requires the invertor to be used even when on shorepower, fine its works but its inefficient.

There are two choices (a) Invertor power whole boat and you selectively disable certain high power AC consumers.

WHat I did was to rewire my AC panel, such that I had some AC consumers on a dual circuit. On loss of shorepower, these circuits are automatically switched to the invertor AC feed. ( same AC breakers, different RCD). I used a change over contactor ( heavy duty AC relay). In my case becuase there was a remote panel , I have two such contactors, but normally one does. Hence when I disconnect the shorepower the common AC consumers are connected to the invertor. I also put in a manual switch to allow the relay to be switched off. These systems are known as Automatic transfer switches

You could also just do it with a change over manual switch. preferably break before make type.



Dave

[Extemporaneous]

Originally Posted by goboatingnow

Your idea requires the invertor to be used even when on shorepower, fine its works but its inefficient.

There are two choices (a) Invertor power whole boat and you selectively disable certain high power AC consumers.

WHat I did was to rewire my AC panel, such that I had some AC consumers on a dual circuit. On loss of shorepower, these circuits are automatically switched to the invertor AC feed. ( same AC breakers, different RCD). I used a change over contactor ( heavy duty AC relay). In my case becuase there was a remote panel , I have two such contactors, but normally one does. Hence when I disconnect the shorepower the common AC consumers are connected to the invertor. I also put in a manual switch to allow the relay to be switched off. These systems are known as Automatic transfer switches

You could also just do it with a change over manual switch. preferably break before make type.

Dave

Okay, Thanks Dave.
My inverter has an "Automatic transfer switch" and so I guess I'm covered unless I'm misunderstanding something??
The attached is from my Magnum Energy MS2012 Pure Sine Inverter/Charger.

Thanks,
Extemp.

[Extemporaneous]

This is indeed critical to get right.

Originally Posted by DeepFrz

I would suggest a return line directly from your alternator instead of through your engine block.

In my first Diagram, the one in which you based the above comment on, I had my alternator tied directly back to my main DC Negative Buss Bar. After some thought I could see that I would be creating a Ground loop and so removed it in my latest update.

Originally Posted by DeepFrz

I will elaborate a bit on my comment on your return line from the alternator to the ground bus. You can run a cable directly from the alternator to the main ground bus, which is the preferred way. It looks like you have the return run through your alternator mounting, through the engine block, to the return line at the starter, back to the ground bus. The main ground bus should not be your engine block, but a dedicated bus. You don't want the return current running through the engine block in any way. It should only run in electrical cable. If it is wired correctly you wouldn't need to show your engine block in the wiring diagram.

And so.... will I or won't I be creating a Ground loop?? This is where I got some very good info. http://www.cruisersforum.com/forums/...gers-5459.html
Perhaps I've misunderstood something is the thread. Always possible!

Thanks for Everyone's input.

Keep it coming.
Extemp.

[goboatingnow]

My inverter has an "Automatic transfer switch" and so I guess I'm covered unless I'm misunderstanding something??

Yes that'll do nicely.

Dave