Another wiring diagram for review

[Bill Roosa]

OK guys, I guess the only thing I'm taking away from this is
1) some boats are designed so it is easy to make mistakes with the switch.
2) The Captain has not installed a plackard near the poorly engineered switch so he (or anybody else) does not have to remember which way to turn the switch. something like "<--OFF - 1 - Both - 2 -->" and a magnet/ring on one of 4 pins above the words/etc to indicate the current state of the switch. or a mirror...... lots of things you could do in about 15 minutes to make it brother-in-law proof.
Still not buying the switch can blow the diodes and think it is an alternator sense wire location issue and the switch in off or the "other bank" position just keeps the regulator from knowing what the alternator is actually doing. My argument is the LC (inductanc/capacitance) of that circuit is so low there is not much of a chance of a spike being formed that could blow a 50V diode. Course if you have an energized (is actively carring current in its winding) solenoid (starter, battery isolation, etc) in that circuit and did not properly "filter" it with a capacitor you could certainly get 50 volts by turning off the switch and dumping all that magnetic field into the circuit.

3) I'm slowly getting the opinion that somebody changed the basic laws of physics sometime in the late 90s.

 

[brazenarticle]

long cable run to selector switch

On my Catalina 28 (1991 MK I) the batteries are behind a bulkhead under the steering quadrant. That makes for a long wire run to the battery selector switch at the nav station, then back to the engine - Probably close to 10 feet of wire routed under and behind the head on the way to the switch.
Maybe this is an idea from out of left field - but.....
Would it be possible to use a solenoid switch at each battery bank, wired too and controlled by the main selector at the nav station? That keeps the #2 cable runs short and the ACR close to the battery compartment.

 

[Bill Roosa]

Yes brazenatricle, you could use a selector switch to control solenoids that actually control the high current circuits. While a 3-way (300 amp rated) would be massive overkill it would provide a more recognized way to control the circuit. Do you have other wires coming off the common post that would have to be re-run? Might make the whole idea dumb if you are just exchanging one long run for another and adding complexity with the extra control wires and solenoids.

 

[Maine Sail]

On my Catalina 28 (1991 MK I) the batteries are behind a bulkhead under the steering quadrant. That makes for a long wire run to the battery selector switch at the nav station, then back to the engine - Probably close to 10 feet of wire routed under and behind the head on the way to the switch.
Maybe this is an idea from out of left field - but.....
Would it be possible to use a solenoid switch at each battery bank, wired too and controlled by the main selector at the nav station? That keeps the #2 cable runs short and the ACR close to the battery compartment.

This is done all the time with the Blue Sea Remote Battery Switches... These are high current remote latching style relays. Not inexpensive but built for the purpose and heavy duty. I prefer the models with the yellow manual override switch.. You do need their activation switches though because these are "latching" style relays. Just make a blanking plate for the old switch..

Blue Sea ML Remote Battery Switches

 

[Maine Sail]

Still not buying the switch can blow the diodes and think it is an alternator sense wire location issue and the switch in off or the "other bank" position just keeps the regulator from knowing what the alternator is actually doing. My argument is the LC (inductanc/capacitance) of that circuit is so low there is not much of a chance of a spike being formed that could blow a 50V diode. Course if you have an energized (is actively carring current in its winding) solenoid (starter, battery isolation, etc) in that circuit and did not properly "filter" it with a capacitor you could certainly get 50 volts by turning off the switch and dumping all that magnetic field into the circuit.

Sorry Bill you are simply wrong on this. This has NOTHING to do with where the alt is sensed. The alts I see blown are almost always "machine sensed" or self sensing alts. I have three -re-built alternators in my shop currently that were fried by swithching through off when the alts were loaded. One is a Delco of a Perkins and the other two are Hitachi alts off Yanmar's.. I only have them because the owners chose new or to upgrade rather than re-build...

With remote sensing the alt output and volt sense must feed and sense the same location or you FRY a second battery when the battery switch is moved to another position. I see this quite frequently on DIY installs of HO alternators... Here's how that one usually goes...

Alt runs through "C" post of battery switch, regulator senses house bank directly, not the alt. Owner manually selects the start bank, regulator sees NO RISE in voltage at the house bank so keeps pumping the voltage up until the start battery is fried.. Just had a $500.00 AGM toasted this way in August on a trawler.

3) I'm slowly getting the opinion that somebody changed the basic laws of physics sometime in the late 90s.

You seem to be writing your own laws of physics and arguing in circles about something that happens with such a high level of regularity that nearly every battery switch maker PLASTERS the warnings about it right there on the switch OR offer an AFD (alternator field disconnect) terminal which prevents the frying of the diodes...... Both of these measures, the warning and the AFD feature are there to prevent something you claim can not or simply does not happen.. The only one re-writing physics here is the "Great Roosa"...

Perhaps your time could be better spent "educating" companies like Perko, Blue Sea, Guest, Balmar, Ample Power, Electromaax and others on how disconnecting a load from a working alternaotr does not cause blown diodes....

This is straight out of Balmar's manual, you know, the people who actually MAKE alternators..

Balmar Manual
"NEVER operate the alternator with switches in OFF position (doing so could cause alternator diode damage)."

The all CAPS of the word NEVER is Balmar not me...

 

[brazenarticle]

Not near the boat at the moment, as I recall there is the wire off the "C" stud to the engine (guessing about 8 feet) and a short ( 18 inches max) wire to the main panel.
I'll be replacing the stock cable with #2 wire, if I use a SPST solenoid on each bank I'll only need to replace the common wire from the selector with the heavier gauge. The other #2 cables will be 4-5 feet from battery to engine.
I just received a Westerbeke starter solenoid, not sure how many amps it is rated for but the cost was $34, about the same as buying new cable.

Just checked the Blue Sea 7700 - true, it is not inexpensive! Back to reality I guess I'll run new heavier copper.

 

[Maine Sail]

Not near the boat at the moment, as I recall there is the wire off the "C" stud to the engine (guessing about 8 feet) and a short ( 18 inches max) wire to the main panel.
I'll be replacing the stock cable with #2 wire, if I use a SPST solenoid on each bank I'll only need to replace the common wire from the selector with the heavier gauge. The other #2 cables will be 4-5 feet from battery to engine.
I just received a Westerbeke starter solenoid, not sure how many amps it is rated for but the cost was $34, about the same as buying new cable.

I would not use those solenoids for battery switches. For a short term emergency parallel solenoid they can work ok but as your sole battery switch they are not well suited.

They also have a high "draw" when latched where an electronic "latching" battery switch, like the Blue Sea ML series, uses virtually no power to keep the batteries on-line.

I have a start solenoid on my bench right now that draws about 1A to remain "latched". So if you had a two bank system, one dedicated start battery and one house, that is a 2A draw just to have the batteries turned on. In 24 hours that is 48Ah's of consumption just to have the batteries on-line... Or better said the entire usable capacity of a 100Ah battery would be used just keeping two batteries on-line. Even if you had just one solenoid activated, for a house/everything bank, you are still burning 25% of the total usable capacity of a 100Ah battery in 24 hours on the boat.....



The duty ratings of that type of solenoid are really in-sufficient for that type of use. Hunter tried to use them on some applications for cross-connect and I have had to replace quite a few of them.

 

[woodster]

Sorry Bill you are simply wrong on this. This has NOTHING to do with where the alt is sensed. The alts I see blown are almost always "machine sensed" or self sensing alts. I have three -re-built alternators in my shop currently that were fried by swithching through off when the alts were loaded. One is a Delco of a Perkins and the other two are Hitachi alts off Yanmar's.. I only have them because the owners chose new or to upgrade rather than re-build...

With remote sensing the alt output and volt sense must feed and sense the same location or you FRY a second battery when the battery switch is moved to another position. I see this quite frequently on DIY installs of HO alternators... Here's how that one usually goes...

Alt runs through "C" post of battery switch, regulator senses house bank directly, not the alt. Owner manually selects the start bank, regulator sees NO RISE in voltage at the house bank so keeps pumping the voltage up until the start battery is fried.. Just had a $500.00 AGM toasted this way in August on a trawler.

sooooo based on this statement it is best to wire the alt output directly to the house bank and then let the ECO charger worry about the start battery and be done with the confusion .....

regards

woody

 

[Stu Jackson]

Woody, you're right. Maine Sail and I have been discussing this on this and other forums for many, many years.

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

Reply #24 on page 2 of this topic discusses Bill's issue with blown diodes.

 

[woodster]

Woody, you're right. Maine Sail and I have been discussing this on this and other forums for many, many years.

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

Reply #24 on page 2 of this topic discusses Bill's issue with blown diodes.

if every one did this then main sail would be out of the alt rebuilding service....

this to me is the kiss way and is not hard to remember when you may have a problem ei dead house bank it also lets the batts take care of them selves via the echo charger and the alt detecting full charge lots of pluses in doing it this way...

thanks for the thread stu......

regards

woody

 

[Maine Sail]

if every one did this then main sail would be out of the alt rebuilding service....

I no longer rebuild them, I send them out. I simply can't do it for what a shop that specializes in this can do it for. When I say "rebuild" I am really diagnosing then removing then dropping off at Rick's shop, who usually calls me the next day to have me come pick it up. He does this WAY cheaper than I can......

this to me is the kiss way and is not hard to remember when you may have a problem ei dead house bank it also lets the batts take care of them selves via the echo charger and the alt detecting full charge lots of pluses in doing it this way...

thanks for the thread stu......

regards

woody

Lots of my customers love those upgrades but many still do it manually and are just very careful. They usually spring for the "upgrades" when they blow the diodes.

When it comes right down to it is a very inexpensive upgrade, in terms of boat bucks, for the simplicity it affords...

 

[Chris Patterson]

Maine, Stu, or whoever, most of what I read here is very comprehensible to me, but in the "two switch wiring diagram", why a disconnect between the starter and battery? Ease of servicing?

 

[Stu Jackson]

Chris, not sure about your question. It's not simply a disconnect switch. It functions in conjunction with the 1-2-B switch for the second type of wiring.

Functionally, it's quite well described.

???Follow the electrons???

1 - If the starting battery goes bad simply turn the 1/2/BOTH/OFF to BOTH and flip the ON/OFF to OFF you can now start your engine and do house loads off the house bank yet still 100% isolate the starting battery.

2 - If the House bank goes bad simply flip to position #2 and leave the ON/OFF turned to ON. This will allow powering house and starting loads from the starting battery and allows it to also act as a reserve.

3 - For normal everyday use flip the 1/2/BOTH/OFF to #1 and the ON/OFF to ON.

 

[Bill Roosa]

So how is this more useful than just using the 3-way with out the switch.
switch to 1 to power everything with the house
switch to 2 to power everything with the start
leave it on Both the majority of the time.

All this gives you is the ability to both run the house loads off the house and start the engine off the start battery at the same time. I suppose that if you had some really heavy absolutely critical house loads that you could not afford to turn off this would be handy but for the life of me I can't think of such a load(s) or situation. I'm of the opinion that if I isolated the battery for a night on the hook and then find that the house is drained down so low that it can't start the engine (always try that first BTW so I can see how "low can you go") that I'd certainly not be letting the First Mate blow dry her hair with the start battery before I got the engine started. Course this setup would not let you do that either as the house is drained already.

Also this will blow your diodes (sic) if you switch to #1 on the 3-way and OFF on the on/off switch will it not? sounds pretty easy to do (HFE)


some one care to show me a real world application where this "saved the day" and a 3-way (used properly) could not? For startes I'm not thinking that this improves HFE at all since I now have two switches to play with and have to actually understand how the wiring works to set them correctly. Normal is #1 and ON??? what about the #2 battery? Now how do I isolate the start now that I'm on the hook? Switch the on/off to off. Still not getting what #2 is for (speaking as a nephrite here). Aw crap I forgot to isolate the starter and now everything is dead (same issue as a 3-way BTW) now how do I set these things so I can get the motor started. I guess I have 7 more combinations to try.

Now If you just rename (placard over the face) the 3-way as following you actually don't have to understand anything: (#1 is house)
#1 --> on anchor and long sails
BOTH --> motor or short sails or shore power connected
#2 --> emergency engine start
OFF --> emergency disconnect or maintenance

Sometimes just renaming things makes the problem go away. Learned that in the Army BTW
And since MS major argument is HFE in most of his discussion on the wiring pages........

I'm not trying to be a pain here guys. If the real issue is HFE then KISS and minimal operator training would be the order of the day or massively automated and engineered so that it works like a car with no user input. The massively automated has complexity and we are talking electrons and sea water so I'm thinking the the former is better than the latter in this case.

 

[Bill Roosa]

The only way this can work with no operator knowledge or skill is with two alternators. the stock one used only for charging the engine and starting and not connected to anything else except the common ground, and a start button and a second high output with 3 stage regulator for the rest of the boat to include the engine instruments. Course you can only do that with a diesel but that is not much of a problem in our case.

No switches at all, just sail till the house dies and start the engine (worst case) This leads directly to the question "well how do I keep the house batteries charged so the First Mate can blow dry her hair in the morning?" Which leads to "you HAVE to understand how much power you are using and manage it." Which would lead one to believe that you really don't have an option on NOT understanding your electrical system.

Just another form of natural selection IMHO.

 

[Maine Sail]

So how is this more useful than just using the 3-way with out the switch.
switch to 1 to power everything with the house
switch to 2 to power everything with the start
leave it on Both the majority of the time.

All this gives you is the ability to both run the house loads off the house and start the engine off the start battery at the same time. I suppose that if you had some really heavy absolutely critical house loads that you could not afford to turn off this would be handy but for the life of me I can't think of such a load(s) or situation. I'm of the opinion that if I isolated the battery for a night on the hook and then find that the house is drained down so low that it can't start the engine (always try that first BTW so I can see how "low can you go") that I'd certainly not be letting the First Mate blow dry her hair with the start battery before I got the engine started. Course this setup would not let you do that either as the house is drained already.

Also this will blow your diodes (sic) if you switch to #1 on the 3-way and OFF on the on/off switch will it not? sounds pretty easy to do (HFE)


some one care to show me a real world application where this "saved the day" and a 3-way (used properly) could not? For startes I'm not thinking that this improves HFE at all since I now have two switches to play with and have to actually understand how the wiring works to set them correctly. Normal is #1 and ON??? what about the #2 battery? Now how do I isolate the start now that I'm on the hook? Switch the on/off to off. Still not getting what #2 is for (speaking as a nephrite here). Aw crap I forgot to isolate the starter and now everything is dead (same issue as a 3-way BTW) now how do I set these things so I can get the motor started. I guess I have 7 more combinations to try.

Now If you just rename (placard over the face) the 3-way as following you actually don't have to understand anything: (#1 is house)
#1 --> on anchor and long sails
BOTH --> motor or short sails or shore power connected
#2 --> emergency engine start
OFF --> emergency disconnect or maintenance

Sometimes just renaming things makes the problem go away. Learned that in the Army BTW
And since MS major argument is HFE in most of his discussion on the wiring pages........

I'm not trying to be a pain here guys. If the real issue is HFE then KISS and minimal operator training would be the order of the day or massively automated and engineered so that it works like a car with no user input. The massively automated has complexity and we are talking electrons and sea water so I'm thinking the the former is better than the latter in this case.

Bill,

If you cared to read carefully that is an ALTERNATIVE wiring diagram for those who are "insist' on using a dedicated starting battery used for starting purposes only. It is also for the sailor who wants the utmost in redundancy and already has an installed 1/2/BOTH. Some other switches that shoot only for simplicity lack the safety and redundancy.

It is NOT one I generally recommend unless someone insists on it. It does have HEF involved but if that's what SOMEONE wants it is just another option. I very clearly stated that this system is more "complicated" and that labeling is a good idea.

On most sailboats, with a decent sized house bank, and good battery practices, there should be zero reason to need to use anything other than the house bank, for everything, including starting.. This takes us right back to using the 1/2/BOTH as a use only ON/OFF switch....

I actually prefer three simple ON/OFF's to the 1/2/BOTH/OFF + ON/OFF but many boats already have a 1/2/BOTH that fits an expensive AC/DC panel..

The Blue Sea DCP is the most simple but lacks redundancy unless the owner is capable of manually isolating a bad battery by wiring changes, in the event of an issue with a bank.

 

[Stu Jackson]

And to add, in all fairness, as we've said many times before, these are but two options in design for the systems and skippers with 1-2-B switches. Maine Sail just said there are others, and those links and MS just described the deficiencies of the Dual Circuit Plus switch.

Indeed, one should have no "issues" with a boat wired with the AO going through the C post of a 1-2-B switch (as many boats were originally configued) with two caveats: 1) the skipper understands the system; 2) and is willing to deal with HEF.

Bill you're right about the use of the switch. Our point here is to get the AO off the C post, switch use remains as you've described. Simple.

 

[Maine Sail]

The only way this can work with no operator knowledge or skill is with two alternators.

Once again TOTALLY FALSE and misleading... PLEASE read the links before you give poor/bad advice that is simply untrue..

 

[SailingHarry]

I just received a Westerbeke starter solenoid, not sure how many amps it is rated for but the cost was $34, about the same as buying new cable.

The issue here isn't so much the "amps" -- I'm sure it is rated for massive amps -- as much as the duty cycle. A starter solenoid runs a few seconds at a crack. If you want it to run continuous, you need one rated for continuous duty. I'm not sure what your exact intent is, but if it is to replace the battery switch and feed your house loads, it needs to be rated continuous. You really do need to be careful, as solenoids that LOOK identical can be rated differently.

Harry