Q about negative connection at distribution panel

[coopec43]

Montanan QUOTE 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.QUOTE

I posted this comment yesterday(on a new thread) Do you have any comments?

"Thinking about it a bit more I could install the circuit breaker beside the inverter (under the companionway steps) without too much trouble. That would be within a meter of the batteries.

I just looked at the circuit diagram and realised the isolating switch is closer to the battery than the circuit breaker.

The way I propose doing it the circuit breaker would be closer to the batteries than the isolating switch. My logic tells me it doesn't matter..... ??

Clive

[Wotname]

Originally Posted by coopec43

Montanan QUOTE 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.QUOTE

I posted this comment yesterday(on a new thread) Do you have any comments?

"Thinking about it a bit more I could install the circuit breaker beside the inverter (under the companionway steps) without too much trouble. That would be within a meter of the batteries.

I just looked at the circuit diagram and realised the isolating switch is closer to the battery than the circuit breaker.

The way I propose doing it the circuit breaker would be closer to the batteries than the isolating switch. My logic tells me it doesn't matter..... ??

Clive

It doesn't matter until it does matter..

Without knowing all the details it can safety be said that best practice is the following order:
battery +ve, circuit breaker close by, isolating switch anywhere before the solenoid (if using a solenoid), load (i.e. winch), negative lead, battery.

Doing it this way means the rest of the details don't matter.

Each component has a particular purpose in the circuit and doing it the above way means each component is doing it's job as it is meant to do. Changing the order requires additional protection to be installed to achieve the same degree of protection (e.g. providing physical protection to the wiring, separating the +ve and -ve leads etc)

[coopec43]

Originally Posted by Wotname

It doesn't matter until it does matter..

Without knowing all the details it can safety be said that best practice is the following order:
battery +ve, circuit breaker close by, isolating switch anywhere before the solenoid (if using a solenoid), load (i.e. winch), negative lead, battery.

Doing it this way means the rest of the details don't matter.

Each component has a particular purpose in the circuit and doing it the above way means each component is doing it's job as it is meant to do. Changing the order requires additional protection to be installed to achieve the same degree of protection (e.g. providing physical protection to the wiring, separating the +ve and -ve leads etc)

Muir winch people say the isolating switch should be near the battery and that makes sense as you don't want live, heavy amperage cables going the full length of the yacht un-necessarily.

"Isolating Switch. This should be fitted in an accessible position for safety, ideally close to the battery or switches. The isolating switch is not a circuit breaker."

The Muir circuit diagram shows the Battery +ve, isolating switch then the circuit breaker (I am putting the circuit breaker before the isolating switch which I judge is of no concern)

(I have re-posted the circuit diagram below)

Clive

[mitiempo]

Originally Posted by coopec43

Muir winch people say the isolating switch should be near the battery and that makes sense as you don't want live, heavy amperage cables going the full length of the yacht un-necessarily.

Clive

The ideal is the breaker or fuse within 7" of the battery positive post. This is what a surveyor in North America would want to see. It leaves virtually all cabling protected. The proximity to the positive post is one reason I prefer a fuse instead of a breaker.

The isolation switch can be anywhere along the cable that is convenient. There is no reason for it to be located where it will not get used. You want it off when the windlass is not being used.

[Wotname]

I have a very high regard for Muir products and I have had three of their winches however I contend they haven't followed best electrical practice in this instance. Their wiring could be an acceptable practice if the suggestions I have made to their drawing were followed.

Originally Posted by coopec43

Muir winch people say the isolating switch should be near the battery and that makes sense as you don't want live, heavy amperage cables going the full length of the yacht un-necessarily.

Remember the heavy amperage cables are live anytime the switch is ON. Should the switch be left on inadvertently, the cables are live. The switch itself does not provide any current protection when ON. Only the circuit breaker offers that which is why it should be close to the source.

"Isolating Switch. This should be fitted in an accessible position for safety, ideally close to the battery or switches. The isolating switch is not a circuit breaker."

I concur with this but at no time should be before the circuit breaker.

The Muir circuit diagram shows the Battery +ve, isolating switch then the circuit breaker

I contend they are in error for best practice and I guess no one has advised them. They are up the road and next time I'm going past I'll call in and have a chat about this. In the past, they have been quite friendly . One of their customer relations guys was an ex aviation electrical engineer IIRC and we talk the same language

(I am putting the circuit breaker before the isolating switch which I judge is of no concern)

I suggest your method is perfect

(I have re-posted the circuit diagram below)

Clive

[Terra Nova]

Typically power comes off the battery to a fuse (rather than circuit breaker) and then to a battery (isolation) switch.

[rbrake]

The negative part of the circuit must equal the positive side of the circuit in resistance, or lack of. If you have 20 14g wires connected to a voltmeter and then a 2/0 battery cable running to the negative terminal of the battery no problem. If you have 20 14g wires running to a voltmeter and then one 14g wire running to the battery, problem.

The first happens when a system is planned by a competent electrician, the second happens when the electrician follows the "just keep touching wires until something happens" approach.

[er9]

Originally Posted by rbrake

The negative part of the circuit must equal the positive side of the circuit in resistance, or lack of. If you have 20 14g wires connected to a voltmeter and then a 2/0 battery cable running to the negative terminal of the battery no problem. If you have 20 14g wires running to a voltmeter and then one 14g wire running to the battery, problem.

The first happens when a system is planned by a competent electrician, the second happens when the electrician follows the "just keep touching wires until something happens" approach.

luckily I have the former but I do have to say their standards were far lower in 1980. it appears some of the electrical was cobbled together with whatever might have been lying around or surplus parts. lots of soldering as well. its held up since 1980 with apparently no problems but some not so smart things done...for example...lots of pinched wires run over bulkheads through fiberglass openings so tight I had trouble pulling the old wires out. think they ran the wiring before the deck was bolted /tabbed to the hull...luckily everything is fairly accessible and easy to get to.

[Uncle Bob]

Originally Posted by cal40john

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

Your advice may well be correct for North America, not necessarily for the rest of the world.