Review electrical design

[Stu Jackson]

Originally Posted by Uncle Bob

You may not however many do in many parts of the world, following the principle that the most important battery on board is the one that is needed when the house fails, charge it first and then the house.

Bob, I am aware of that. The part that I don't get is that doing it that way indicates a complete lack of understanding how a combiner works. Once the voltage rises from charging, the combiner closes. Since alternator charging on even a depleted bank will usually "trigger" the combiner, then many of us never understood the logic to run larger current than necessary through the combiner. That's all. BTDT with this discussion. And, of course, start banks are rarely depleted, separate story. Finally, he was in either Vancouver or the American PNW, not "other parts of the world" and "we" don't. Maine Sail and I used to have this discussion over on ybw, but we both gave up. Guess they had fear of not starting from all their MGs and Lucas non-starters.


For the OP, since this will be a new to you electrical system, consider the concept.

[Jerry Woodward]

Originally Posted by smac999

Yes. Turn the house switch off in his diagram and tell me what happens. (while charging)


Same reason the battery charger is wired to the battery. And not to the house switch.

2 problems happen.

I'm also getting ready to do some re-wiring and trying to understand where to locate switches. Can you educate me on why the inverter charger cannot be wired after the "house" switch, with the understanding that that switch is always on, and only there as an emergency cut off, service, or when you leave the boat. Used this way, the switch should never be turned off while charging. But, can you enlighten me on what would happen if the switch was turned off while charging?

[chowdan]

My apologizes everyone. The batteries are 6v not 12v. I am about to head out so i can't respond in detail, but i do appreciate everyones help so far! Great tips and recommendations.

I'll give an updated diagram later tonight or tomorrow after I get back from doing my errands.

[smac999]

Originally Posted by Jerry Woodward

I'm also getting ready to do some re-wiring and trying to understand where to locate switches. Can you educate me on why the inverter charger cannot be wired after the "house" switch, with the understanding that that switch is always on, and only there as an emergency cut off, service, or when you leave the boat. Used this way, the switch should never be turned off while charging. But, can you enlighten me on what would happen if the switch was turned off while charging?

if the house swtih is turned off, A. the battery stops charging. so you can't shut the house switch off and leave the boat. and B. when you shut it off, the charger is still running and powering everything directly. so when you shut the house swtich off, all the lights, electrics etc all stay on. which is really confusing... and really bad for the charger is it not designed to directly power loads.

you should have a seperate house switch and inverter swtich. if you want to leave the boat with the house swtich off, you can. loads are powered down and the battery is still charging. if you need to service the boat, turn both off. normally both are fed seperatlly from the battery with separate fuses since the inverter fuse and wire will be much bigger then the house feed wire.

genarlly I put the inverter swtich near the battery or near inverter. not near a house panel or house swtich etc. A because of wire lengh, and B so people never turn it off. as it's only a service switch.

[Uncle Bob]

Originally Posted by Stu Jackson

Bob, I am aware of that. The part that I don't get is that doing it that way indicates a complete lack of understanding how a combiner works. Once the voltage rises from charging, the combiner closes. Since alternator charging on even a depleted bank will usually "trigger" the combiner, then many of us never understood the logic to run larger current than necessary through the combiner. That's all. BTDT with this discussion. And, of course, start banks are rarely depleted, separate story. Finally, he was in either Vancouver or the American PNW, not "other parts of the world" and "we" don't. Maine Sail and I used to have this discussion over on ybw, but we both gave up. Guess they had fear of not starting from all their MGs and Lucas non-starters.


For the OP, since this will be a new to you electrical system, consider the concept.

Stu, I understand if there is a large output alt installed, however taking my boat as an example, my alt is 60 amp and the most that I have ever seen going into my house bank is 40 amps, for a very short time then tapering off to around 17 amps then to only a couple, according to the victron monitor. I normally only see around 14 amps, usually lower. I have 190 watts of solar and the battery is usually at around 13.5 to 13.7 at end of day. the bank is 6 6 volt 235 amp hour FLA batteries. My understanding is that the batteries dictate what they will accept. The combiner is only in use when the engine is running and very capable of handling the amperage. Mabee not perfect however works very well in my circumstances but if you truly believe that it can be improved I am all ears, as they say.

[rom]

Originally Posted by smac999

if the house swtih is turned off, A. the battery stops charging. so you can't shut the house switch off and leave the boat. and B. when you shut it off, the charger is still running and powering everything directly. so when you shut the house swtich off, all the lights, electrics etc all stay on. which is really confusing... and really bad for the charger is it not designed to directly power loads.

you should have a seperate house switch and inverter swtich. if you want to leave the boat with the house swtich off, you can. loads are powered down and the battery is still charging. if you need to service the boat, turn both off. normally both are fed seperatlly from the battery with separate fuses since the inverter fuse and wire will be much bigger then the house feed wire.

genarlly I put the inverter swtich near the battery or near inverter. not near a house panel or house swtich etc. A because of wire lengh, and B so people never turn it off. as it's only a service switch.

So, your inverter switch is really an inverter switch but your house switch is what ? a DC load switch ? Poor choice of name to me. But anyway, I think you forgot to mention that what works for you may not work for others. I just left my boat unattended for 6 weeks and decided to switch off the house batt. Which I did with the house switch. I also turned off the inverter/charger which comes with its own on/off/charger button. And i also turned off the solar panels and mppt controllers. Works well for me.

[chowdan]

Originally Posted by rom

So, your inverter switch is really an inverter switch but your house switch is what ? a DC load switch ? Poor choice of name to me. But anyway, I think you forgot to mention that what works for you may not work for others. I just left my boat unattended for 6 weeks and decided to switch off the house batt. Which I did with the house switch. I also turned off the inverter/charger which comes with its own on/off/charger button. And i also turned off the solar panels and mppt controllers. Works well for me.

I need to read my manual more, but due to focusing on my charger system right now, I havent had time.

That being said, why would one have an inverter switch? If they do where is the switch located - on the load side or power supply side? If load side, what is the purpose? My inverter has a on/off button...

[chowdan]

Hey all, here is my updated version. Sorry for long delay. I think I'm going to change it to run windlass directly from the battery, not through then house fuse. Ideas on this?

[Stu Jackson]

Originally Posted by Uncle Bob

Stu, I understand if there is a large output alt installed, however taking my boat as an example, my alt is 60 amp and the most that I have ever seen going into my house bank is 40 amps, for a very short time then tapering off to around 17 amps then to only a couple, according to the victron monitor. I normally only see around 14 amps, usually lower. I have 190 watts of solar and the battery is usually at around 13.5 to 13.7 at end of day. the bank is 6 6 volt 235 amp hour FLA batteries. My understanding is that the batteries dictate what they will accept. The combiner is only in use when the engine is running and very capable of handling the amperage. Mabee not perfect however works very well in my circumstances but if you truly believe that it can be improved I am all ears, as they say.

Bob,

What you're saying is your house bank is almost pretty well topped off all the time. That's great.
Regardless of alternator size and "refueling" of the house bank by other sources, the concept is basically that "After a days of use the house bank will ALWAYS "need" more amps than the start bank." That's all it is. Any charging source should go to the house bank.
Use an ACR/VSR or simply B on the switch WHEN CHARGING. Do the second one and it costs you nothing.


Your boat, your choice.