Battery Switch Wiring

[Maine Sail]

Originally Posted by tedsherrin

Actually, I've drawn up a repeat of your fuse panel and incorporated the switch. So I have two questions.

Firstly, where does the Alt go?
Secondly, where does the no 2 position on the battery switch go?

Ted
Colour drawing attached.

Ted,

You really might want to take the time to investigate your options, of which there are many, for battery wiring. In my system the house bank provides starting and house duties and the second bank is simply treated as a reserve. Some prefer starting isolation and don't want to do that so you need to weigh the options that you want vs. how to wire it. I would define what you want out of the system first then come up with a diagram.

The alternator in that system is fed directly to the house bank. The three ANL's on the left are bused together with large copper bar stock and connect directly to the house bank. The house bank connected to the middle fuse the alt on the left and the battery charger on the right fuse. The inverter fuse is not "bused" to the other three fuses and is turned on via the battery switch. The only reason I have four fuses is because I have four different sized wires which are differing in ampacity ratings.

I just did an install a few weeks ago with just one fuse but the alt, battery bank to switch and inverter were all the same size wire thus could be protected by the same size fuse. It helped keep the costs down for the customer too.

Many ways to skin the cat...

[Rustic Charm]

Originally Posted by Stu Jackson

Have you read the links in Reply #12?

Yes, very thoroughly. But that does not mean I completely understand everything, hense I drew a diagram incorporating both to check I was correct. My back ground is mechanical and social. I have very little knowledge of 12v systems other than knowing it hurts or blows expensive things up when you get it wrong. Hense why I want to get it right.

Thanks Stu.

[Rustic Charm]

Originally Posted by Maine Sail

Ted,

You really might want to take the time to investigate your options, of which there are many, for battery wiring. In my system the house bank provides starting and house duties and the second bank is simply treated as a reserve.
The alternator in that system is fed directly to the house bank. The three ANL's on the left are bused together with large copper bar stock and connect directly to the house bank. The house bank connected to the middle fuse the alt on the left and the battery charger on the right fuse. The only reason I have four fuses is because I have four different sized wires which are differing in ampacity ratings.

Thanks Mainsail,
Having read a lot of the posts I'm favouring having the engine batter as a reserve too. From what I have read this avoids the problem of missing a good bank with a flat bank when you need to combine them.

I now understand that if I'm starting from scratch (which I am, then I don't need to have four separate fuses, I'll just use all the same wire, thanks)

If you could please just tolorate me a little more.

You said the "Alternator is fed directly into the house bank", and you also said that in relation to the three ANL fuses, the 'Alt' is on the left (?). So when you say the 'alternator is fed directly intot he house bank', do you mean via the back of that ANL fuse on the left? (or does Alt stand for something other than 'alternator'?

Secondly (lastly I hope), you can see in the diagram I drew up incorporating your two drawings, what is the number 2 on the switch used for?

[Maine Sail]

Originally Posted by tedsherrin

If you could please just tolorate me a little more.

You said the "Alternator is fed directly into the house bank", and you also said that in relation to the three ANL fuses, the 'Alt' is on the left (?).

The alternator fuse is on the left. The alternator output wire comes in the bottom of that fuse and out the top which is connected to the house battery. It is a direct feed from the alternator to the house bank via an ANL fuse sized for the alternator wire.

Originally Posted by tedsherrin

Secondly (lastly I hope), you can see in the diagram I drew up incorporating your two drawings, what is the number 2 on the switch used for?

The single fuse on the left is for BANK #2. Switch position #2 is for the second bank and switch position #1 is for the house bank..

[Stu Jackson]

What MS said is: "If all the wires going to the PDP are the same gauge, then you can use one fuse."

That's because the fuses protect the wire.

I recommend taking a night off, reading the "stuff" we lined you to, and trying again in two days.

Why bother?

Really, it'll come to you if you reread the links.

[FlyingCloud1937]

Originally Posted by Stu Jackson

What MS said is: "If all the wires going to the PDP are the same gauge, then you can use one fuse."

That's because the fuses protect the wire.

I recommend taking a night off, reading the "stuff" we lined you to, and trying again in two days.

Why bother?

Really, it'll come to you if you reread the links.

Stu...and all,

I have one Q....

If ya use one fuse, and we have three circuits, and there is a fault in one of the circuite's wouldn't that mean that all 3 circuits are with-out bat power?


Hi All..

Now when I wire a boat(make that a yacht...I mean, make that a boat)
I wire as follows;

#1 main Bat Fuse.
#2 Nav/Com
#3 ER
#4 Helm
#5 House

Now mind you I tend to create sep.bat banks for #2, #3/4, & 5.

BUT IN NO EVENT WILL an overload on 5 create a blackout on 4,3,2 or 1.

now if there is an inverter on board, that is a seperate fuse, it's #6.

If number #6 goes, it will have no effect on the previous 5,4,3,2,1

Lloyd,

ifyourgoingtogotoseathenbesafe

[Pete7]

Originally Posted by tedsherrin

I have a few dollars at the moment. Would you recommend I get the stirling Alternator regulator for my system then? They are $199 in Australia. Ted

Perhaps not, really depends on how you want to charge the house bank regularly? The options are shore power, solar and wind, genny or boat engine. If you are regularly motoring somewhere then fine, but don't run the main engine just to charge the house bank, its terribly inefficient and running an engine under light load isn't good for it. Decide how you are going to regularly charge the house bank and invest the money there.

Pete

[Maine Sail]

Originally Posted by FlyingCloud1937

Stu...and all,

I have one Q....

If ya use one fuse, and we have three circuits, and there is a fault in one of the circuite's wouldn't that mean that all 3 circuits are with-out bat power?


Hi All..

Now when I wire a boat(make that a yacht...I mean, make that a boat)
I wire as follows;

#1 main Bat Fuse.
#2 Nav/Com
#3 ER
#4 Helm
#5 House

Now mind you I tend to create sep.bat banks for #2, #3/4, & 5.

BUT IN NO EVENT WILL an overload on 5 create a blackout on 4,3,2 or 1.

now if there is an inverter on board, that is a seperate fuse, it's #6.

If number #6 goes, it will have no effect on the previous 5,4,3,2,1

Lloyd,

ifyourgoingtogotoseathenbesafe

The owner, an EE, was fully aware of the limits one fuse poses. He still preferred it to having multiples.. Usually every load gets its own. The point was not that you " should use" one fuse but rather you "can" and there are many options. He chose to not have multiples and to save money. I am happy because at least he has a fuse now. ANY fusing in the battery cabling is better than what that owner, and perhaps 85% of the boats in the US have, which is ZERO fusing..

That boat (not a "yacht") also has a separate dedicated engine starting battery/circuit ... I also offered him the future potential upgrade of three MRBF fuses directly off the pos dist bus bar and left room to do so.. His boat, his choice, all I can do is make recommendations because in the end he writes the check..

[slowshoes]

Originally Posted by Maine Sail

Ted,

You really might want to take the time to investigate your options, of which there are many, for battery wiring. In my system the house bank provides starting and house duties and the second bank is simply treated as a reserve. Some prefer starting isolation and don't want to do that so you need to weigh the options that you want vs. how to wire it. I would define what you want out of the system first then come up with a diagram.

The alternator in that system is fed directly to the house bank. The three ANL's on the left are bused together with large copper bar stock and connect directly to the house bank. The house bank connected to the middle fuse the alt on the left and the battery charger on the right fuse. The inverter fuse is not "bused" to the other three fuses and is turned on via the battery switch. The only reason I have four fuses is because I have four different sized wires which are differing in ampacity ratings.

I just did an install a few weeks ago with just one fuse but the alt, battery bank to switch and inverter were all the same size wire thus could be protected by the same size fuse. It helped keep the costs down for the customer too.

Many ways to skin the cat...

Maine Sail,

Thanks for all of the info - I can assure you it's helping many of us out. A quick question - where did you find your battery hold downs, Did you have them made custom? I've never seen them before and I am in the market for something a bit more robust than what I've been using.

[Rustic Charm]

Well, thanks everyone to date. I'm really happy now the way I have set up the system. It's all finally connected and seems to be working well. . The only thing I havn't checked is that the Blueseas ACR is charging the reserve battery (yes I went for a reserve battery rather than engine starter, which means I have battery selector always to no 1 or off).

I've made all my own battery cables from 35mm, which was already on the boat. I took Mainsail's (Ithink) suggestiong and purchased a 360 degree crimper which cost just $120 on ebay in Australia. It's brilliant.

Just a quick question, I'm now up to installing my new switch panel which I have made. In choosing the oppropriate fuses or curcuit breakers (I'm using the push button curcuit breaker kind), how do you determine the size circuit breaker or fuse if you no longer have a manual with items. e.g my fridge/freezer compressor draws 5amps.. the cable I have it on is 50amp cable. Do I put in say a 10amp circuit breaker or fuse? Bigger or smaller?

Regards and thanks for all the help guys (especially Stu).

Ted, Tasmania, Australia

(Ps, if I can work out how to post some pictures I'll post some shortly, some might find it interesting, I might even build a web page, but I have no idea how to do that yet. )

[Wotname]

Originally Posted by tedsherrin

Well, thanks everyone to date. I'm really happy now the way I have set up the system. It's all finally connected and seems to be working well. . The only thing I havn't checked is that the Blueseas ACR is charging the reserve battery (yes I went for a reserve battery rather than engine starter, which means I have battery selector always to no 1 or off).

I've made all my own battery cables from 35mm, which was already on the boat. I took Mainsail's (Ithink) suggestiong and purchased a 360 degree crimper which cost just $120 on ebay in Australia. It's brilliant.

Just a quick question, I'm now up to installing my new switch panel which I have made. In choosing the oppropriate fuses or curcuit breakers (I'm using the push button curcuit breaker kind), how do you determine the size circuit breaker or fuse if you no longer have a manual with items. e.g my fridge/freezer compressor draws 5amps.. the cable I have it on is 50amp cable. Do I put in say a 10amp circuit breaker or fuse? Bigger or smaller?

Regards and thanks for all the help guys (especially Stu).

Ted, Tasmania, Australia

(Ps, if I can work out how to post some pictures I'll post some shortly, some might find it interesting, I might even build a web page, but I have no idea how to do that yet. )

First principles tell that the circuit protection is sized to save the wiring, not the device on the end of the wire. Therefore the maximum rating for circuit protection should never be greater than what the wire is rated for. It is OK to go smaller providing you stay above the whatever the current is that the load requires.

Lets say your wire is rated at 20 amps and your load is drawing 4 amps maximum. First principles would suggest a fuse between 5 and 20 amps would be suitable. I tend to opt for something in the middle and would use a 10 amp fuse here. Bear in mind that some loads have a high inrush current and that has to accommodated in your choice of fuse and/or circuit breaker. A rule of thumb is that a standard fuse will carry small overloads better than a circuit breaker. If you have more than one load on the circuit, you have to add the additional loads together to ensure your circuit protection (and wiring!) is suitable.

Now you can get complicated and work out the ambient temperatures, number of wires in a bundle, average % load of each wire, response times of circuit breakers, fuses (standard, fast acting, slow blow), device protection and so on BUT I reckon just stick to basics and then go sailing .

FWIW, I only use 5, 10 and 20 amp fuses (except for main bus).

[btrayfors]

Wotname has provided what IMHO is pretty good advice.

I would just add that in addition to the circuit breaker on the panel, some loads need their own fuses of a specified rating and this can be very important.

Sensitive electronics and other small devices should be protected with fuses specified by the manufacturer.

Also, for example, a small motor device like a bilge pump can actually burn up if you don't use the proper (specified) size fuse; we've given demonstrations of just that at West Marine seminars.

Bottom line: set up the overall electrical distribution system intelligently, and pay close attention to the specified fusing requirements of individual components on the system.

Bill

[phantomracer]

Originally Posted by btrayfors

The preferred way is to wire ALL charging sources to the house batteries, then use a combiner or, better, a voltage-follower device like an EchoCharge or DuoCharge to maintain the start battery. This way, there's no need to switch anything...the batteries are maintained automatically.

Here, again, is the way I like to do it on client's boats...

Attachment 41790

Bill

I just did this on my boat. Converted from just 1-2-b-n switch to using a duo-charge, following this diagram (provided on the thread I started a while back). Other than the duocharge install, just had to add a battery switch and one new battery cable to my setup. Pretty easy.

Makes life sooo simple now. NO battery switching. Just start and go!!

[btrayfors]

Glad it worked out for you.

There are lots of ways to skin a cat, as they say.

I'm just completing the rewiring on a smallish vessel where space is somewhat constrained. We began with the DC system.

Here's what we started with:



We decided to go with a three switch ON-OFF system using Blue Sea Systems #6006 battery switches (not shown in pic, but black arrow points to where these were installed; that small panel under the lip is actually the forward end of the port cockpit locker, so lots of room behind it).

We replaced the little panel, and built a completely new DC panel -- the Blue Sea Systems #8402 10-position breaker panel shown here, mounted on a custom 5/8" teak frame:



This panel has a digital multimeter at the top which can show voltage for three battery banks (switchable) and amperage for any desired bank.

To conserve space and maintain some logic, we built this main DC board on a 1/2" x 10" x 9" starboard panel. It contains the ANL fuses for the house bank (250A), the start bank (300A), the 500A shunt for the ammeter, a 4-position negative bus, a 2-position positive bus, and the Xantrex EchoCharge.



Weather permitting (it's been god awful hot here) we'll finish up this week.

Bill

[Rustic Charm]

Hi everyone again.. a quick question. I've purchased an installed a new Windlass, (Muir, a heavy duty sucker at that) and have used the appropriate size cable which was ó' or 45mm I think. Should I attached the windlass to the reserve battery, or to the bank?