Q about negative connection at distribution panel

[Wotname]

^^ is the battery located forward near to the winch?

Yes, keep the circuit breaker close to the battery (assuming the battery is located above any expected water ingress).

[P3sailor]

I would install it on your main electrical distribution panel. It should be relatively close to your power source and in the event of an emergency easy to locate.

[Wotname]

Coopec43, without wanting to derail er9's negative busbar thread, can you post your planned wiring diagram (either here or a new thread) because it doesn't sound like you are following best practice - but this might be my misunderstanding of what you have written.

For instance, is your isolation switch in the low current or high current circuit of your solenoid (assuming you are fitting a solenoid)?

[coopec43]

Originally Posted by Wotname

As others have posted, the circuit breaker must be placed close to the source, not near the load.

The switch is necessary and should be placed where convenient.
The purpose of the switch is to prevent inadvertent / accidental / unintentional winch operation; usually the winch is turned on only when needed. Circuit breakers do not make good switches, their mechanical cyclic life is quite low (especially when compared to the cycle life of a switch).

There are of course some designed as a combined "circuit breaker and switch" which do have a high cycle life; typically they look like lever or toggle switch but of course they still need to be located close to the source.

There are cheap 100A circuit breakers that you can buy for $30 but mine is a Muir "combined circuit breaker/Isolator Switch" which cost $154. (I suppose there was really no need to install a separate isolator switch)



Clive

[mitiempo]

My preference for protecting wires to heavy loads such as windlasses and thrusters is fuses - Anl, Terminal, or Class T - instead of breakers. Breakers are often installed where convenient while fuses are most often installed close to the feed positive where they should be.

There is also the AIC rating vs battery bank size to consider. Many breakers don't qualify with a high enough rating.

[coopec43]

Originally Posted by mitiempo

My preference for protecting wires to heavy loads such as windlasses and thrusters is fuses - Anl, Terminal, or Class T - instead of breakers. Breakers are often installed where convenient while fuses are most often installed close to the feed positive where they should be.

There is also the AIC rating vs battery bank size to consider. Many breakers don't qualify with a high enough rating.

I'm aware there are also time delay circuit breakers which will allow an overload for a short time. I just read up on AIC ratings but I really don't understand it. I have a Muir winch and a Muir circuit breaker so I hope they have thought it all out.

With my knowledge I find it challenging to work out the circuit where all the options are on one circuit diagram:

• There are two and three pole motors.
• Some installations are UP as well as DOWN.
• Some foot switches are UP and some DOWN
• Some foot switches - press the front to go down and the back to go up.
• Wiring for remote controls

Thanks for your advice

Clive

[cal40john]

Originally Posted by billknny

This shows a very basic, and very common, misunderstanding of what a circuit breaker or fuse is for. It is to protect the WIRES not the device.

In your case you have a pari of very large high amperage cables running from the power panel to the winch that are, apparently, unprotected. If through accident, wear, or misadventure, there was to be a short circuit between those wires, they would almost literally explode into flame as the full force of the battery pushed through them. Don't tell me "It can't happen."

If you have never seen the result of a dead short with even a small 12 volt battery, you should. It should be part of every boatbuilders required education. Wires heat in a fraction of a second to temperatures hot enough that molten copper trailing flame sprays every where, while smoke form the vaporized insulation fills the space. It is truly awe-inspiring.

No external fuse or breaker will do anything to protect your winch motor. The motor might (or might not!) have internal thermal protection to prevent an overload, but that is a different matter.

I have seen 3 boat fires, put out two of them and a boat gas explosion. They are frightening events. Most boat fires are either galley or electrical in origin. If you don't know what you are doing, it is far better to leave even deceptively simple DC wiring to people who do.

The below is separate and in addition to the normal circuit breakers folks have been talking about, properly placed near the source.

There are circuit breakers designed to protect motors. The ones on the motors I worked with, the manufacturer called breakers, the company in the link below calls them relays. They are adjustable to the exact specs for the motor.
https://www.schneider-electric.com/e...tegory-id=1520

[mitiempo]

Originally Posted by coopec43

I'm aware there are also time delay circuit breakers which will allow an overload for a short time. I just read up on AIC ratings but I really don't understand it.
Clive

AIC stands for Ampere Interrupt Capacity. It is the maximum current that a breaker is designed to safely interrupt. If this is exceeded the breaker may arc over and fuse the contact points together, closing the circuit. When there is a major short circuit this is the last thing you want. The larger the battery bank the higher the AIC rating is needed.

More information here: https://www.bluesea.com/support/arti...uit_Protection

Most marine rated breakers have an AIC rating of 3000 or 5000 depending on series from Blue Seas. Fuses can have much higher AIC ratings.

Blue Seas terminal fuses have an AIC rating of 10000 @ 14 volts

Blue Seas ANL fuses have an AIC rating of 6000 @ 32 volts (much higher @ 14 volts)

Blue Seas Class T fuses have an AIC rating of 20000 @ 125 volt DC. This is the type most inverter manufacturers suggest be used.

[Wotname]

Originally Posted by coopec43

There are cheap 100A circuit breakers that you can buy for $30 but mine is a Muir "combined circuit breaker/Isolator Switch" which cost $154. (I suppose there was really no need to install a separate isolator switch)



Clive

The guys at Muir's strongly advised me to fit a seperate isolation switch even though they had supplied a Muir combined circuit breaker / isolator switch with their winch.

They hinted that while their circuit breaker could be used as a switch, I would get a far longer service life from the breaker if it wasn't used as a switch. This matched my knowledge of a lifetime of electronics (land / marine / air) so I took their "hint".

[seabreez]

Originally Posted by Terra Nova

The circuit breaker must be installed near the power source--not the load.

I just finished wiring a tugboat and the circuit breakers are supposed to be installed within 24 inches from the power source. And to add to the "grounding", now called "bonding" the color of all bonding wires should be "yellow" to prevent confusion between green and black grounds if multiple voltages are used for example 12 volts 24 volts and 110 or 220 volts. The inspectors also insisted all connections be crimped and copped thinned without drilling out the connectors. They all had to be proper sized for the stud connectors.

[seabreez]

Forgot to add that all connectors had to be shrink wrap type and all battery cables connectors had to be shrink wrapped also.

[seabreez]

Originally Posted by P3sailor

Now, on a slightly different note, are there any boats out there that utilize a "case ground" say for lights, etc. I was on an older wooden boat and it seems to me that all of the originally installed lights were case ground. Any thoughts?

If you use anything that is case ground... it Is not meant for boat use. All equipment for nautical or commercial use for sea is all made with a "ground, bonding wire" for the return to the batteries. Some manufacturers install a spade connector on the case if you want to add a ground. And some even wire a proper return to the batteries and even add a green wire. I had to remove all grounds from cases and wire the "bonding wire" to return to the power source.

[cal40john]

Originally Posted by seabreez

I just finished wiring a tugboat and the circuit breakers are supposed to be installed within 24 inches from the power source. And to add to the "grounding", now called "bonding" the color of all bonding wires should be "yellow" to prevent confusion between green and black grounds if multiple voltages are used for example 12 volts 24 volts and 110 or 220 volts. The inspectors also insisted all connections be crimped and copped thinned without drilling out the connectors. They all had to be proper sized for the stud connectors.

Bonding and DC return or DC negative are different.
ABYC
Green - bonding
Yellow (black still listed but discouraged) - DC return

Yellow is promoted as the DC return to avoid confusion with 120 volt AC wiring which has black as the Hot wire .

https://www.proboat.com/2015/04/the-...tems-revealed/
"In the simplest of terms, bonding systems are an interconnection of underwater metallic components,"
"That’s the how, but why bond? Interconnection of these underwater metals protects against stray-current and galvanic corrosion. "

https://www.defender.com/pdf/abyc-wire-color-chart.pdf

[Montanan]

"Now where do I install the circuit breaker? Under the floor boards near the battery? But looking at one of the manufacture's drawings of a motor boat it looks like near the helm (that's not going to happen on my yacht)"

You answered your own question and would be following the advice of the responses by locating the circuit breaker near the battery. The positioning of circuit breakers must function so as to protect the wiring leading from the power source to the device loads, and thence also the remainder of the CIRCUIT. Question: What kind of a breaker is the safety device? Answer: A CIRCUIT BREAKER. Protect the entirety of the circuit, not just a portion; place the breaker[s] at the beginning of the circuit[s]. That is why circuit breakers are customarily mounted at the power source distribution panels, i.e., look at your home source panel beginning from the meter, there will be a high amperage main breaker between the utility power source and the distribution bus and then smaller amperage breakers for each of the individual distribution circuits. Size the wiring appropriately for each circuit, including the wiring from the primary power source to the distribution panel.
As to the breaker panel being mounted under the floor boards, I would hope you are not suggesting or considering the bilge area where water can enter. Elevate your circuit breaker panel so as to not be the low point of your vessel. Leave the bilge clear for the rats to run about and the water to slosh about.

[er9]

Originally Posted by Wotname

Coopec43, without wanting to derail er9's negative busbar thread, can you post your planned wiring diagram (either here or a new thread) because it doesn't sound like you are following best practice - but this might be my misunderstanding of what you have written.

For instance, is your isolation switch in the low current or high current circuit of your solenoid (assuming you are fitting a solenoid)?

no worries feel free to post away. Helps me learn more also as original question has been clearly answered.