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New wiring diagram- please critique!

9K views 33 replies 9 participants last post by  Waltthesalt 
#1 ·


I have concerns with the location of the Blue Sea ACR... will it feed the start (emergency) battery properly from a distribution bus (I can't see why this would be an issue). The reason I would like it tied off the buss and not directly off the house battery, is that my house is locate on the starboard side and start is on port. This will shorten the wire run I need to do for the ACR wire.

Also, does it look like I have the fuses in the correct location?

Thanks for the quick insight.

Matt Johnson
 
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#2 · (Edited by Moderator)
For the ACR you will still want a large gauge wire to connect it to both batteries (circuits). You can connect the house side via the bus, just make sure the positive bus is rated for a high enough current. It looks like your fuses are close to the positive sources so that is good.

Do you purposely not have your windlass running through your distribution panel?
 
#4 ·
Why don't you have a fuse on the engine start circuit?

Also, what is the wire coming off the BlueSea VSM going to the AC panel?

Also, why go through all this trouble only to have a standard 1-2-both switch in place? It would make much more sense to have a BlueSea Dual Circuit Plus switch instead, so you can start the engine off the start bank, run the house loads off the house bank and isolate the two systems.
 
#5 · (Edited)
Why don't you have a fuse on the engine start circuit?
I keep reading conflicting data on that subject. It sounds like you are for having the start circuit fused.

Also, what is the wire coming off the BlueSea VSM going to the AC panel?
It was suppose to be the ac current coil. Is that not the correct way to wire it?

Also, why go through all this trouble only to have a standard 1-2-both switch in place? It would make much more sense to have a BlueSea Dual Circuit Plus switch instead, so you can start the engine off the start bank, run the house loads off the house bank and isolate the two systems.
Because Mainsail said I should keep it! I like the idea of getting to the boat, putting the switch to 1 and keeping it there. If I need to, I can then switch to the emergency position number 2 and connect with the other battery. What negatives are there to using the existing switch?

Thanks for your response.
 
#8 · (Edited)
I have concerns with the location of the Blue Sea ACR... will it feed the start (emergency) battery properly from a distribution bus (I can't see why this would be an issue). The reason I would like it tied off the buss and not directly off the house battery, is that my house is locate on the starboard side and start is on port. This will shorten the wire run I need to do for the ACR wire.

Also, does it look like I have the fuses in the correct location?
Matt,

The major issue you have is that your start (reserve) bank and your house bank are incorrectly tied together on the positive side. They are NOT separated, regardless of your ACR location. The acr should be between the two positives of your house and reserve bank, not where it is shown.

You seem to have a complete misunderstanding of bus bars.

It appears you are using a simple 1-2-B switch, in which case you may be interested in reading this, starting with reply #11: Alternator/Batteries & "The Basic" 1-2-B Switch BEST Wiring Diagrams

House bank to post 1, reserve bank to post 2, output of the switch from the C post is to the DC distribution panel and to the starter, alternator output to the house bank with a circuit breaker rather than a simple fuse, ACR between the reserve and house bank for charging.

You also seem to have connected the DC ground from the house bank to the AC ground through the Blue Seas vsm 422.

I also agree with Maine Sail, see this thread, the issues are down the bottom of the first page and the second page: 310 Battery Info - SailboatOwners.com The Blue Seas dual circuit switch is a disaster waiting to happen and is a stupid design. Stay with the 1-2-B switch, but please learn how it is supposed to work.

A recent post on this board has some other good reference material. http://www.sailnet.com/forums/electrical-systems/60009-best-way-learn-electrical.html Ample Power has already designed the wiring diagrams you NEED. Please read their stuff.

I certainly wouldn't wire my boat this way. Because it simply will not work. Review the linked reference and make some corrections. It won't work as shown. You asked.;)

Stu
 
#10 ·
Don,

I actually want to start off the house bank and use the "start" battery for emergencies only. This way I can come to the boat, put the switch on position #1 and forget it. If I need to, I can then connect to position #2 and start from that battery.

After visiting the boat on Friday, I reconfigured the diagram for shorter cable runs. Due to the location of the charger and "start" battery, it makes more sense to have the ACR located where I now have it and use the charger and start battery's large 2/0 cable for one run. I also was able to remove the bus for all charging sources ($65.00).

 
#11 · (Edited)
Matt,

This is still just as incorrect. The +s of the house and start bank are still connected. You have simply made them one big battery without any switching capability.

And if you are moving stuff around because of where it's located for wire runs you are approaching this completely backwards. The last person I worked on who had this appraoch spent four months wiring and running his incorrectly and finally fixed it.

Design the system first, then wire it on the boat based on the system requirements.

Stu
 
#12 · (Edited)
Stu,

I can revise the diagram to show that the wire for the ACR are connected to the #1 and #2 position on the switch and not intersecting the start positive wire, but I don't see where you are getting that the house and start are connected.

Here is the corrected diagram:

 
#13 · (Edited)
Matt,

You can redraw the diagram all you want, but that is not my point. You need to understand how the basic system works, that includes these basic errors:

1. Using a positive distribution bus and then feeding equipment without switches (only fuses are shown) is wrong because this equipment will always be live; no functional change from the last diagram since my last comments.

2. Each of the house and start bank +s MUST go the posts1 & 2 of the 1-2-B switch. House + to post 1. Start bank to post 2. They should never be connected before the switch as you've shown. The switch is only there to decide which bank to take power from. Joining the wires from the + posts of each bank defeats this basic concept.

As I mentioned in my first post, it appears that you need to do a lot more research to understand how basic electrical systems are wired.

All I can do now is to recommend that you read the links I provided for you earlier, and try again, with a clean sheet of paper, rather than trying to salvage this one. Go back to basics. The location of the components is nice, but the wiring is all wrong, primarily the positives. The link to this board's electricla basics had good ideas from many folks, including the analogy to water piping. If you trace your diagram carefully, and follow the electrons or water droplets, you'll see why it will not work.

Another issue: You show the engine at the bottom. You show two positive connections, top left and bottom left. Is the top one the alternator? Is the bottom the starter solenoid? It would be helpful to identify them.

The purpose of bus bars is to gather wiring that is to be at the same potential. As shown it works for the negatives because the grounds all go to the engine and you're using the bus bar as a convenient way to gather wires before the final wire from the bus bar to the engine. [I leave out the connection of the AC ground wire; this is a separate subject and a completely different and sometimes contentious electrical design issue.]

It does not work that way for positive wires. Each positive wire should have one purpose: taking power from somewhere and going to ONE specific point with a switch, so you can manage it: i.e. turn it on or off. By leaving the C post of the switch and going to the + bus bar, you have violated that basic concept.
 
#16 · (Edited)
Matt,

You can redraw the diagram all you want, but that is not my point. You need to understand how the basic system works, that includes these basic errors:

1. Using a positive distribution bus and then feeding equipment without switches (only fuses are shown) is wrong because this equipment will always be live; no functional change from the last diagram since my last comments.

2. Each of the house and start bank +s MUST go the posts1 & 2 of the 1-2-B switch. House + to post 1. Start bank to post 2. They should never be connected before the switch as you've shown. The switch is only there to decide which bank to take power from. Joining the wires from the + posts of each bank defeats this basic concept.
Actually, his diagram doesn't have the house bank + going anywhere but the alternator output and the 1 post on the switch.

The start bank's + goes to the AC powered charger and the 2 post on the switch.

They're certainly not connected to each other in any way I can see. If you're seeing something different, please point it out.

As I mentioned in my first post, it appears that you need to do a lot more research to understand how basic electrical systems are wired.

All I can do now is to recommend that you read the links I provided for you earlier, and try again, with a clean sheet of paper, rather than trying to salvage this one. Go back to basics. The location of the components is nice, but the wiring is all wrong, primarily the positives. The link to this board's electricla basics had good ideas from many folks, including the analogy to water piping. If you trace your diagram carefully, and follow the electrons or water droplets, you'll see why it will not work.

Another issue: You show the engine at the bottom. You show two positive connections, top left and bottom left. Is the top one the alternator? Is the bottom the starter solenoid? It would be helpful to identify them.
Common sense and the diagram pretty clearly shows the upper left is an alternator... when was the last time you saw a belt driving a starter motor??

The purpose of bus bars is to gather wiring that is to be at the same potential. As shown it works for the negatives because the grounds all go to the engine and you're using the bus bar as a convenient way to gather wires before the final wire from the bus bar to the engine. [I leave out the connection of the AC ground wire; this is a separate subject and a completely different and sometimes contentious electrical design issue.]

It does not work that way for positive wires. Each positive wire should have one purpose: taking power from somewhere and going to ONE specific point with a switch, so you can manage it: i.e. turn it on or off. By leaving the C post of the switch and going to the + bus bar, you have violated that basic concept.
While I don't agree with the windlass and inverter being hardwired to the positive bus, and feel they should go through a switch of some sort, there isn't really anything wrong-other than the lack of a switch on the circuit-with wiring them to the bus bar to give them the 12 VDC feed they require.

The one worry I do have is having the inverter on the bus bar, since most inverters draw extremely large amounts of current. I don't know if the OP has sized the wire going from the switch to the + bus bar to accommodate all of the loads. If he had the inverter on and running and started the engine-the amperage being drawn from the batteries would be quite a lot. A 1000W inverter, the smallest size that is generally hardwired on a boat, draws about 100 amps with losses.

Depending on the length of the wiring runs, it might make far more sense to have the inverter attached directly to the house bank with a fuse and switch in-line. I'd point out that there should never be any reason to run the inverter off the starting battery.
 
#14 ·
I don't think it makes sense to hardwire an invertor to part of your AC system (plug-ins) and still have shorepower on line if at the dock. A safer way is to hardwire the invertor to the AC panel like the one shown below. Yhe invertor goes to the position marked "generator". These panels are available with either voltmeters or ammeters to show AC use. This way there is never a danger of having the shorepower and invertor both online at the same time. I would use the VSM422 to monitor the invertor rather than shorepower. Your AC panel will tell you if there is reverse polarity and you really don't need anything else. The invertor is more critical to monitor. I would also install a galvanic isolator in the incoming AC earth (green wire).

I would install a separate on/off switch in the main lead to the windlass so it can be defeated before the fuse for safety. I would install the ACR directly between the 2 battery banks and run all charging to the house bank which will leave the 1/2 switch with less connections and possibly shorten some wiring.
 

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#15 · (Edited)
I don't think it makes sense to hardwire an invertor to part of your AC system (plug-ins) and still have shorepower on line if at the dock. A safer way is to hardwire the invertor to the AC panel like the one shown below.
Brian, it is not only safer, it's required, because if two different AC loads are available at the same time, one of 'em is gonna blow up! He doesn't necessarily need one of those panels, a Blue Seas 8032 source isolation switch would do it. Inverter Installation If he wants his inverter to run his outlets when not at a dock, then the AC inverter output must go to the AC panel input as an AC source or else it's not gonna work. If not, then he has an inverter but has to run extension wires from his appliances to the inverter, which makes little sense to me.

But Matt's got bigger issues right now, his DC side. We'll get to the inverter and the need for an isolating switch on the incoming AC side later.
 
#17 ·
Stu
The 8032 would work but if he hasn't purchased an AC panel might as well get it all in one.
Like I said I'd get the ACR off the 1/2 switch and between the batteries where it belongs, send all charge sources to the house bank direct and install an on/off in the windlass run before the fuse. I see no problem with the positive distribution bus being there as it keeps wiring off the switch but I would wire the invertor direct to the house bank. I can't see ever using it off the start battery anyway and this will make the wiring run shorter. This way the only feeds from the positive bus would be the windlass, starter, and DC distribution panel.
 
#18 · (Edited)
dawg, you're right, I was wrong. The start and house are separated, but how does he charge the house bank? Ah, thru the ACR. But that's backwards because the charger should go to the house bank so as not to have to run all the current through the ACR. And the house output splits without a switch to the alternator, where the alternator output should go to the bank, not a wire splice. Functionally may be the same, but one would expect to see two wires in the real world: house to post 1, alternator output to house bank.

Piffle on the alternator labeling, but given the other issues, it would be appropriate to label them. You're right about the belt.

The bus bar downstream of the C post is just optional, as shown, although I agree that switches would make a lot of sense.

I agree with Brian.
 
#19 ·
The house bank is charged underway by the alternator directly. At the dock, it is charged via the ACR and the AC battery charger as you note. I would move the AC charger output to the house bank instead of putting it on the starting bank... as that does make no sense.

I agree the ACR would be better wired to the house and starting banks directly, but there may be physical reasons that prevent that from being a simple solution in his boat.
 
#20 ·
Matt, I don't mean to chase you away, just that these comments have hopefully gotten you closer to designing something that works. I've worked with many skippers to help design their systems. Each one started off with discussions, and I continued to suggest that they do a wiring diagram FIRST. You're way ahead of the curve. Keep up with the comments and you'll get there. Stu
 
#21 · (Edited)
Thanks for all the help and time guys.

The reason for the charger going to the start battery and not the house is mostly due to location and expected use. I will be on a mooring or anchor 99% of the time and the charger will see little use (it's a Pro mariner 30 amp). It's located away from the house bank and within 2 feet of the start "emergency bank". With the very little use the charger will see, would running it through the ACR make sense (I don't plan on the house bank charging from the battery charger except when on the hard)? I could then use the one 2/0 AWG wire I'm running from the 1/2 both switch to the charger and start battery.

The rest of the connections from battery, starter, buss bars ACR and inverter are all connected with 2/0AWG cable. For the length of run on the rest of the circuit, that seems to be the proper size.

The inverter is an Xantrex XM1000 which has the built in transfer switch. I wanted to run just the outlets from the inverter at all times. If shore power is connected, the inverter will still be in path for that circuit. (This was suggested in Nigel Calder's Boatowners Mechanical and Electrical)

The windlass is a Lewmar Concept 1 with a 700 watt motor. Both the windlass and inverter are getting protected with circuit breakers like these... do I still need a switch?

 
#22 · (Edited)
Yes you still need a switch for the windlass. Windlasses have managed to short their switches out and the fuse shouldn't be the only protection. A switch in the off position when not using the windlass is essential. A neighbor did not have one and he was away when the windlass shorted - the fire was small but the expense was high. I believe ABYC requires it as well.

The invertor you are using does have an automatic transfer switch. But I am curious where you will be sourcing the AC for the input. If your outlets are on separate circuits that would complicate the wiring. If they are on the same circuit they could be fed from just that circuit. But you said you want to run the outlets from the invertor at all times. By using the transfer switch built into the invertor they will automatically be on shorepower when you are connected to it. Also as I said I would wire the invertor direct to the house bank and not to the positive bus as you have it shown. I don't think you will ever want to draw from the emergency battery for the invertor.

I would still move the ACR to a direct line between the battery banks. I do not like more than 1 wire on each connection of the 1/2 switch.

Your wiring sizing is fine.

I'd still run the charger to the house bank and not the emergency battery. That is where most of its output will be going. You could relocate the charger closer to the house bank.
 
#23 ·
If I run the windlass and inverter off the battery lug, aren't I stacking that one lug too much? The reason for the buss was to avoid stacking any lugs or bolts.

The on/off switch you are talking about is one of these?



Also, can you typically retrofit a panel to have a sliding lockout like was shown? I currently have Bass panels that all have the same cosmetic look. I would like to try and keep that same aesthetic, but they no longer make these panels. AC is to the far right.

 
#26 ·
A couple points.

First, you can use the smaller size of those switches for the windlass. That way it takes up less space.

You may have to modify the AC panel slightly to run the AC out of it and into the Inverter, and then have the inverter output go to the AC breakers. The reason is that some AC panels have a solid bus bar connecting the AC circuit breakers with the other end of the main AC hot circuit breaker. A hack saw fixes this quite nicely though.
 
#24 ·
Yes that is the correct type of switch for the windlass. Remember the windlass will draw a similar amount of power as your starter but for longer and more than all your other loads added up.

No you can't update a panel because it doesn't have a second AC input to start with. But as I said in my previous post (after reading the invertor manual) you can take the AC off the panel from the outlet breaker to the AC in on the invertor and then to the outlets from there. This would mean no changes are required to your existing AC panel.
 
#25 ·
you can take the AC off the panel from the outlet breaker to the AC in on the inverter and then to the outlets from there. This would mean no changes are required to your existing AC panel.
Brilliant!!! I finally understand. That is the direction I'm going to go!

:thewave:

I'll also get a second switch mounted for the windlass and run that from the battery.

Thanks for all the help!
 
#28 · (Edited)
A far simpler way to deal with the two sources of AC is the Blue Seas 9009 switch.
Shore power comes in one side and inverter the other. The output then runs to your panel. With this switch you can not back feed either shore or the inverter as neither can be on at the same time. It actually will cost less money, and save precious breaker space on the panel, than buying a 30 amp double pole breaker and making a custom lockout switch plate. Just consider "GEN" as your inverter.



Manventure Outpost has it for $69.00
 
#29 ·
Good point MS... but I believe the OP wants to use the Inverter in automatic transfer mode, which is not possible with that switch.
 
#31 ·
How did you do your wiring diagram

Hi funjohnson,

How did you draw out your wiring diagram? A software program, an online service, you're a really great artist?

I'm redoing my electrical system and have been drawing it by hand. I love to work up something like you've done.

Thanks,
Matt
 
#34 ·
Your diagram looks workable to me. I'm used to seeing the VSR between the batt terminals rather than across the batt select switch. A 1000KW inverter is a big DC load 83 amps. I'd put a breaker on it instead of a fuse so that I could power it up only when I'm going to use it. Also keep the DC current in mind on cable lenght and voltage drop. I'd recommend using tables for 1% line loss if the manufacturer doesn't give you recommendations. The problem you want to avoid is having the inverter's battery protection circutry sense a low DC voltage due to line losses while the inverter is under load and then alarming and/or shutting down the inverter.
As for battery fuses there are some pricey but nifty ones out now that fit on the terminals.
One thing you want to monitor is amp hours in and out. Your VSM should do that. It's important to optimise your charging/discharging.
It's hard to tell how your battery selector switch works. I removed my old batt 2, 2 and both switch use an early version of Blue Seas DC battery distribution swithboard . It consists of two manual switches and one circuit breaker. One manual switch provides engine power from the start bank. Annother is a cross connect switch that lets the house bank power the engine start circutry. The 100 amp breaker provides the house power from the house bank. I like this because I can leave the switches in only one position for sailing. I have significantly different sized battery banks, one quite large, and the start considerably smaller and don't like the idea of cross connecting them given that they may have significantly different voltages from the discharge.
From your ground system I'd recommend you have a galvanic isolator for your shore power.
Just my opinion having rewired my boat recently
 
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