Tap onto 6V batteries in parallel

FF said:

"have their own fusible link"

Do you carry on board replacements , should a problem arise?

Class T fuses are rated for most wire amperage used on boats , and replacements are easily stored and installed.

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Excellent point. Added to my punch list for bringing this old girl into full readiness.

JDCAVE said:

Ok. So therein lies the problem! According to Bluesea: “In any case, fuses, circuit breakers, and switches should not be installed in battery compartments because of the risk of corrosion coupled with the potential presence of explosive gasses.”

So...how do you realistically achieve this? On the stringer near the battery box?

My over current protections located near the positive bus bar, some distance from the battery box. Currently (pardon the pun) I am not in compliance.

Jim

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Maybe an MRBF fuse like this could be used to feed the bus bar.



https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A

IMO any battery boxes' purpose is to keep them from moving, protect from metal objects shorting them and to contain any spillage.

They should **not** be sealed, up but vented to dissipate gasses released.

Sensitive gadgets should not be mounted directly above the batts themselves, or in the venting path, as the fumes are corrosive over time

but the bank fuse(s) should be - if not within 7" - then as close as possible to the post.

72"??? Where did that come from?

The cutoff switch should also be mounted close, but where you can quickly and easily get to it in an incident or before working on wiring.

Ideally the battery compartment area is designed to accommodate these recommendations. If not then modifications or compromises are in order.

Legally??

Looks like title 46 covers commercial boats, title 33 covers gasoline boats. If you have a recreational diesel boat, I have yet to find US legal verbage on wiring near the battery. Must be there somewhere.
There are definately some excellent recomendations, though.

Between CMS / Maine Sail http://www.trawlerforum.com/forums/showthread.php?p=617683

and ABYC specifications

that is "the law"

As enforced by surveyors and insurance companies.

they cant "enforce" anything cause its not "law".

Surveyors can note and suggest, insurers can insist but can also be convinced otherwise.

Some ABYC standards are mentioned in the CFRS like UL standards, but genetally dont apply to recreational vessels except in the manufactuiring stage.

Yes exactly my point.

Great guidelines to follow even if you're self-insured and never going to resell your boat.

I am quoting ABYC standards. Over current protection must be with in 72” of the battery terminal if sheathed wire is used, 7” if unsheathed wire is used, over current protection is not needed on a starting circuit but if you tapp off that circuit you are allowed up to 40” to place overcurrent protection.

ABYC also states a maximum of 4 connections to a battery terminal. Many people quote 3, I do not know we’re that comes from but fewer is better give the corrosive neighborhood of a battery terminal.

ABYC is not law, however it’s always my goal to leave any part of a boat that I touch at or above ABYC standard. Some old boats just can’t be brought up to the standard.

You can be with in the letter of the standard but cheat the spirit, this does not make you safe. You can follow the spirit of the standard but be outside the letter of the standard, this does not make you unsafe.

Aha, sheathed as in wiring conduit correct? That can increase wire gauge required. . .

Yes, I also think striving for best practices wrt electrics is only sensible.

And CMS has pointed out several areas where the ABYC specs are deficient, like termination pull-test standards.

Years ago in my waterfront neighborhood, there was dense, black smoke. I thought it might be a boat fire. Just a few houses down, it was a boat on a trailer. The owner was attempting to put it out with a garden hose. Less than a 20 footer, it was also parked under the eaves, and now he had a house fire on his hands also. No real progress was made until a quint showed up and had it out in about 30 seconds.
It sat around and just looking inside, it seemed likely to me that a long length of wire was responsible, fore to aft. Just a guess though.

ABYC defines unsheathed as a bare wire. One could interpret that a bare wire wrapped in electrical tape as sheathed, however there are also temp ratings to be considered. I would not have a problem with a wire that is coated and stamped with appropriate ratings (voltage, gauge, temp, resistance, marine grade) being considered sheathed.

Wow, I thought the 7" spec was for normal insulated wire!

Hard to imagine anyone running exposed uninsulated bare copper wires any length at all?

john61ct said:

Wow, I thought the 7" spec was for normal insulated wire!

Hard to imagine anyone running exposed uninsulated bare copper wires any length at all?

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I would agree but there might be a reason in some specialized application that we never see.

m. Sheath - A material used as a continuous protective covering, such as overlapping electrical tape,
molded rubber, molded plastic, or flexible tubing, around one or more insulated conductors.

that's the 1990 version. I don't have access to the latest 1998.

I would think sheathed refers to wire that has normal insulation red, black, green etc with a covering over that such as bildge pump wiring with the gray sheathing. Just my guess.

ABYC standards also dictate gauge size and temperature rating. A bare wire wrapped in electrical tape would pass the sheathed requirement but might not pass the temperature rating. I can’t say that it won’t because it just might on a 24 gauge wire.

diver dave said:

m. Sheath - A material used as a continuous protective covering, such as overlapping electrical tape, molded rubber, molded plastic, or flexible tubing, **around one or more insulated conductors.**

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To me that means the sheathing material is in addition to the usual insulation.

IOW the 7" rule is for already insulated wiring, the 42" for when covered with an **additional** covering.

diver dave said:

Years ago in my waterfront neighborhood, there was dense, black smoke. I thought it might be a boat fire. Just a few houses down, it was a boat on a trailer. The owner was attempting to put it out with a garden hose. Less than a 20 footer, it was also parked under the eaves, and now he had a house fire on his hands also. No real progress was made until a quint showed up and had it out in about 30 seconds.
...

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A tough one downunder. Then found this:

"Quint

From Wikipedia, the free encyclopedia

Quint or Quints may refer to:
In music

• A type of sackbut, a musical instrument
• A free-bass system for the accordion invented by Bill Palmer
• A type of pipe organ stop

Vehicles

• Honda Quint, a subcompact car manufactured by Honda of Japan
• Quint (fire apparatus), a fire service apparatus combining features of an engine and a ladder truck
• A tandem bicycle with five seats

People and fictional characters

• Quint (name), a list of people and characters with the surname or given name

Other uses

• NATO Quint, an informal decision-making group consisting of the EU big four and the United States
• Quint -, a numerical prefix meaning five
• A component of a graphical GUI scroll bar widget
• Quintuplets, born as part of a multiple birth with five children
• Quints, a 2000 Disney Channel movie"

john61ct said:

To me that means the sheathing material is in addition to the usual insulation.

IOW the 7" rule is for already insulated wiring, the 42" for when covered with an **additional** covering.

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Diverdave correctly quoted ABYC Standard E-11.4.28. So electrical tape does qualify as a sheathing material but there are other rules to consider and other than a temporary fix we all know that electrical tape would be a poor choice in sheathing material.

tiltrider1 said:

Diverdave correctly quoted ABYC Standard E-11.4.28.

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Yes but my point is that my reading is that insulated marine wiring does not count as "sheathing" on its own, therefore 7" applies without additional cover.

john61ct said:

Yes but my point is that my reading is that insulated marine wiring does not count as "sheathing" on its own, therefore 7" applies without additional cover.

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And that's the funny thing about standards, two people two interpolations. Do you go with the most stringent interpolation, with what is most commonly done, what your surveyor will sign off on, or what's reasonable for a specific situation. Even that answer is not consistent.

Frankly I'm of the camp that a wire covered in continuous molded plastic is sheathed but there are situations were I would only find it acceptable to run it through a conduit. So I'm going to disagree with your interpolation but certainly agree with your practice.

BruceK said:

A tough one downunder. Then found this:

"Quint

From Wikipedia, the free encyclopedia


Vehicles
a fire service apparatus combining features of an engine and a ladder truck

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pumper, ladder, tanker, hoses, aerial.

quint from quintuple. If you have only one item on wheels to put out a fire, that would be it!

Easting said:

I would think sheathed refers to wire that has normal insulation red, black, green etc with a covering over that such as bildge pump wiring with the gray sheathing. Just my guess.

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Electricians ashore might more likely use the terms "approved wireway" and "protected from physical abuse". meaning: conduit, flextite, etc.

A UL product inspector uses the terms like "reinforced insulation" or "supplemental insulation", with very specific requirements.

But we are in the marine context, and are left with some pretty vague terms.

diver dave said:

m. Sheath - A material used as a continuous protective covering, such as overlapping electrical tape, molded rubber, molded plastic, or flexible tubing, around one or more insulated conductors.

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It is perfectly clear to me.

The sheath is material (covering, tape/tubing, made of plastic or rubber)

**around insulated conductors**

Plain English, precisely written, I don't even see room for misinterpretation.

john61ct said:

It is perfectly clear to me.

The sheath is material (covering, tape/tubing, made of plastic or rubber)

**around insulated conductors**

Plain English, precisely written, I don't even see room for misinterpretation.

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The INTENT is quite clear. What is not clear is the acceptable implementation. To my point on the electricians use of "approved wireway". Anything they see as acceptable needs to have a UL mark on it. Yes, even the common EMT, steel conduit has a UL mark. and, its just a piece of steel tubing.

Another example is the ABYC use of the word "plastic". Well, many insulating plastics have horrible flame resistance. I would hate to see us use polyethylene, for instance in an engine space. Its a great electrical insulator, but if it flames for any reason, it will not self-extinguish.

And, don't get me started on TAPE. I hate electrical tape on stuff. When warm for a few decades, it slips, sticky, unwraps. But, you will see many OEM boat makers use a number of individual conductors with an overwrap of tape.

I was just talking about the recommendation that bank CP be located within 7" of the post.

Now I also know if a situation requires up to 42", I will ask for recommendations here about suitable conduit.

diver dave said:

The INTENT is quite clear. What is not clear is the acceptable implementation. To my point on the electricians use of "approved wireway". Anything they see as acceptable needs to have a UL mark on it. Yes, even the common EMT, steel conduit has a UL mark. and, its just a piece of steel tubing.

Another example is the ABYC use of the word "plastic". Well, many insulating plastics have horrible flame resistance. I would hate to see us use polyethylene, for instance in an engine space. Its a great electrical insulator, but if it flames for any reason, it will not self-extinguish.

And, don't get me started on TAPE. I hate electrical tape on stuff. When warm for a few decades, it slips, sticky, unwraps. But, you will see many OEM boat makers use a number of individual conductors with an overwrap of tape.

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Don't tell me! The PO of my boat was a tape lover and wrapped all wires from engine room in electrical tape. Years after with heat and age it became a sticky dirty black thing that I cannot wait to throw away.

L

Good discussion. My boat is not completely ABYC compliant. There were several things that were flagged by the surveyor before I purchased it, but only 1 item that the insurer required be remedied. Now, there are a couple other items that the surveyor did not flag yet are in the current ABYC standards that I intend to upgrade over time. One of those is to come up with better wire protection fusing closer to the batteries. I don't "have" to, but it would be good practice and make good sense.

From what I understand from people who worked in ABYC, the standards are for new construction and new installs more than total application.

Standard not necessarily to automatically upgrade and can accomodate installs that are less than perfect.

The main rub is surveryors and insurance companies CYA to require even old boats to be perfect. Fortunately there are smart and good surveyors and insurance companies that are reasonable.

If ABYC truly thought every single vessel in every single category should absolutly be built exactly the same or brought to the same standard without question,....well...to many different conclusions there.

That is like saying every American car should meet milspec.

psneeld said:

From what I understand from people who worked in ABYC, the standards are for new construction and new installs more than total application.

Standard not necessarily to automatically upgrade and can accomodate installs that are less than perfect.

The main rub is surveryors and insurance companies CYA to require even old boats to be perfect. Fortunately there are smart and good surveyors and insurance companies that are reasonable.

If ABYC truly thought every single vessel in every single category should absolutly be built exactly the same or brought to the same standard without question,....well...to many different conclusions there.

That is like saying every American car should meet milspec.

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ABYC is a good thing. However... I am a mechanic, electrician, rigger (worked for several boat yards over the years). Forums are good for lots of folks to say "you should have a certified electrician do all your work for you". Some boat owners can and should do that. I went to the ABYC site and to my amazement found out it's a private society (so to speak). Oh I can get the information... but I have to join and pay for it.

My beef with ABYC is, if everyone wants to quote ABYC all day and do everything by their standard, make the standard available to everyone. ABYC is not the only way to do things properly and safely.

Kind of like saying all you guys who work on your own cars better get it done by an ASE certified technician or by their specs.