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modified 2-bank topology & switches layouts

Discussion in 'Musings With Maine Sail' started by John61CT, Jan 11, 2017. Add this thread to a FAQ

  1. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    In the ON position, both the Engine/Starter-batt circuits are connected on the one hand, and Primary/House on the other.

    In OFF, both of those two connections are opened/stopped respectively at the same time.

    No connection between the two sides are made in either case, Primary/House is isolated from Starter/Engine on both Load and Bank sides.

    Until you choose Combine, which closes/connects ALL FOUR circuits together - except I would have isolated one of the banks beforehand with its (bottom of diagram) 0/1 switch.

    There's a very HD version of it too:
    https://www.westmarine.com/buy/blue...rcuit-plus-battery-switches--P009_272_004_507
     


    Last edited: Jan 11, 2017
  2. Scott T-Bird

    Scott T-Bird

    Joined Oct 26, 2008
    2,781 posts, 156 likes
    Starwind 27
    US Allamuchy Barnegat, NJ
    There were a lot of answers all happening at the same time. This is the one that I liked to see.
    Thanks for that! Good timing in that electrical system upgrades are in my line-up this winter.
     


  3. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    In my three-switch, only one switch-throw is used in normal practice, the top DCP OFF shuts down the whole boat*, ON turns it on.

    Nothing else I've seen does that. The bottom two never get used except when you need to isolate "bad batt", and the DCP Combine is only used if you want the whole boat to use remaining "good".

    Actually the same as MS' three-switch in an emergency (two flips) and one less in everyday use.

    I agree the four-switch requires separate routine on/off for the two sides just as MS3s, but to me the advantage is new user more easily grasping the layout's logic, both routine and emergency scenarios.

    With proper short & bright labelling of course, but (I think) no checklist/cookbook posting needed.

    Time for single dad here to start my kids' after-school ferrying, look forward to catching up with y'all later.
     


  4. Stu Jackson

    Stu Jackson

    Joined Feb 26, 2004
    19,187 posts, 295 likes
    Catalina 34
    US C34 San Francisco
    My apologies, the DCP has four posts.
     


  5. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    No worries Stu.

    I was attracted to the simple and efficient "one throw both circuits at once" for ON/OFF but I bet it does lead to problems out there.

    Obviously DCP is a bit opaque, as in not intuitive, and to me that in itself is a problem.
     


  6. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    v3.0 iteration

    [​IMG]

    A Dual Circuit (NOT "Plus") at top, labelled MASTER POWER: in day-to-day use this is the ONLY switch needs touching

    One flip to ON connects Accessory Loads to Primary (House) bank AND connects Engine Loads (cranking starter, all non-sensitive running gear) to Reserve (starter) battery, keeping the two sides isolated.

    -----
    B ENGINE switch usually remains on Reserve Starter bank #1, if a problem arises, flip to Primary (house) bank #2.

    OFF automatically shuts off Alternator Field, then isolates all "Boat Loads".

    Edit: ENGINE switch should label position #1 (Reserve starter bank) as NORMAL. Label #2 "Start off House bank", not really an emergency situation, cranking is a rough but easy periodically check on any bank's SoC.

    Note also if the conclusion reached here http://forums.sailboatowners.com/index.php?threads/why-primary-reserve-vs-house-starter.182980/ changes, only a change in label is required.

    -----
    Finally, C Emergency Parallel switch does just that, NORMAL setting is OFF ==> isolation, subject to automatic control based on ACR/Echo voltage sensing.

    That's IT for the three "public" switches, I don't think I can imagine anything simpler from a UI POV retaining all the functionality I want.

    =====
    House panel has its own Master Breaker, can if needed shut down all non-essential loads.

    Each bank has its own circuit breaker (or fuse to save $) after the B+ buss, attached to which is (on Primary) all charge sources including AO, plus VR & SmartGauge (or AH-counter) sensors and "always on" security/safety gear.

    Echo/B2B/combiner keeps Reserve starter topped up when Primary (house) circuit gets above Absorption threshold. Insufficient charging and/or large Load on either side re-isolates banks per low threshold voltage set-point, but this can be manually overridden with the EP switch.

    Note, C Emergency Parallel switch is not specific to Engine vs House loads, that was the silly redundancy in my second "four-switch" layout above. Combined means combined to whatever Banks remain online, Accessory house Loads can be isolated as needed.

    As always, any feedback welcome.
     


    Last edited: Jan 11, 2017
  7. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    Nope, just a poor design, good feedback.

    Let me know what you think of v3.0?
     


  8. MitchM

    MitchM

    Joined Jan 20, 2005
    351 posts, 28 likes
    Nauticat 321 pilothouse 32
    US Erie PA
    once you get your system working, post a big sign DO NOT TOUCH -- THIS MEANS YOU ! so a 12 year old does not play with the pretty switches so as to drain all of your batteries , including engine start battery , in the middle of lake erie on a 4 day cruise .
     


  9. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,177 posts, 244 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    V3.0.. Not very KISS and heck even I can't follow what you are trying to gain/say with V3.0 over the DCP + two ON/OFF's..
     


  10. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    More a revision of the four-switch, but I wanted clarifying labels for both, a more intuitive UI was IMO sorely needed and worth some complexity behind the panel.

    I really like the simpler, obvious Master ON/OFF as a DC rather than DCP, taking the Combine outta there.

    Since I plan/hope to make sure I never need it, I may skip the separate "emergency parallel" switch completely, but for those who want to make such functionality so easy, it should IMO be tucked away in a non-obvious location associated with Engine.

    Moving echo/ACR to the B+ buss (before switches) was necessary for functionality, thanks Stu!

    The "switch cranking to bank X" functionality, which I do plan to use routinely, was **completely** UI-buried in both previous layouts, is IMO also properly associated with Engine, and incorporating AFD makes me feel better about the previously discussed "Alt boom" scenario.

    Changing bank switches to breakers: eliminate duplication, near banks better location anyway.

    House breaker: also just eliminated the unneeded public switches in the second 4S layout.

    Hope that clarifies my intentions, and maybe allows for some detailed suggestions for improvement, from anyone of course, would be appreciated.
     


  11. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    They're pretty well trained, spare the taser spoil the child I always say. :cool:

    But yes, point taken. A sign doesn't do much for some of the game-addled crazies out there, maybe even a locked cover, pin-code like a gun-safe if I were hosting kiddie birthday parties or something
     


  12. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,177 posts, 244 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    When I "modify" DCP switch wiring on customers boat, who want the ability to isolate a bad bank while using the good one to power everything, the ON/OFF switches are out of plain sight, usually in the battery compartment. All the guests and owner see is the DCP ON/OFF switch. The DCP label already has a yellow WARNING placard with an ! for "combine batteries".

    The general wiring would usually look like this. The emergency ON/OFF's are usually within about 7-10" of each bank after the fuse...

    [​IMG]
     


    John61CT and Scott T-Bird like this.
  13. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    Nice

    But what about
    > If you want any level of performance charging them you run all charge sources direct to the house banks always-on bus or the physical battery terminal

    Plus risk of no load dump alt boom if switches isolate while running?
     


  14. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,177 posts, 244 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    The bus on the load side of the house switch is the always on / charge bus in that drawing.. The switch is there only for an emergency or service tech use. It should ALWAYS remain ON unless you have an emergency or a service tech needs full 12V isolation to the engine.

    Under normal use only the DCP is used. ON>OFF very, very simple...

    Often I will use a Blue Sea "keyed" switch with the key on lanyard. No one should ever touch these switches because they are not visible to occupants or crew.

    That's quite a what if....

    What if a meteorite hit the boat and killed the alt??:wink:


    What if Harry Potter flew down on his magic high voltage broom and caused a voltage transient that killed the alt??:biggrin:

    I've been doing this a long, long, long, long time and in all that time never once seen a battery switch magically operate itself.

    If you wire this system the way it should be, concealed emergency isolation switches, installed very, very close to the bank, right after the main bank fuse, there is zero risk of a load dump other than by you the owner.

    A very nice feature of this particular wiring layout is the fact that when or if the house bank goes South, you simply turn the DCP to "BOTH" and then turn off the house bank switch. You now have full isolation AND *the start/reserve bank now receives all charge sources with only two switch flips BOTH and HOUSE ISOLATION OFF. You're now back in business in a few seconds..

    *Important that positive volt sensing for the regulator is also on load side of house emergency switch. This is why it is installed close to the bank for minimum voltage drop..

    The key to this installation is the concealed/out of sight emergency isolation/service tech switches mounted as close to the batteries as possible (right after the fuse)...
     


  15. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    I'm just questioning to get clear in my understanding, not doubting, believe me.

    So in my first 3S drawing, rather than needing to move the echo/ACR down below the switches from Stu's comment, just moving the AO up above would be just as good.

    In that scenario, should the alt voltage sensor stay on the direct-batt side of the switch, or move up with the AO?

    And yes those "keyed" switches are perfect for "only for crises", I'd use one for my standalone "Emergency Parallel" if I included that too.

    Finally, any downside to using a breaker at the batt rather than the switch and fuse?
     


  16. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
  17. John61CT

    John61CT

    Joined Jan 7, 2017
    49 posts, 1 likes
    beneteau 36
    US eastern US new london
    I really like this layout from Maine Sail!

    [​IMG]
     



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