No joy on shore power

[thomm225]

Originally Posted by boatpoker

His questions suggest otherwise.

Some of that was CF'ers not giving him credit. You have to be careful not to say one thing wrong especially technical on a forum like this.

He said something about thinking the Shore Power AC should/would run all systems when plugged in.......

So, he didn't know old sailboat systems is how I saw that.........not that he was clueless about electrical/electronics.

He was navy and 99.9% of all navy jobs/rates are technical in some way

[ramblinrod]

Originally Posted by thomm225

Yes, it's definitely best to check each and every device but it's still up to the individual. Besides on an old boat, you almost need to rewire the thing to be absolutely sure the wiring isn't frayed in places for example that could cause a short etc.

Again, my point exactly.

RE: Old wiring.

If the wiring is "likely" or "expected" to be faulty, check it BEFORE connecting power.

RE: Simple vs complex electrical systems.

An electrical fire does not care how simple or complex the circuit is.

Ohm's Law applies to every single circuit.

What's more, the more simple the circuit, the more easy it is to inspect before applying power.

There simply is no valid excuse for suggesting the wiring not be inspected before connecting power.

[thomm225]

Originally Posted by ramblinrod

Again, my point exactly.

RE: Old wiring.

If the wiring is "likely" or "expected" to be faulty, check it BEFORE connecting power.

RE: Simple vs complex electrical systems.

An electrical fire does not care how simple or complex the circuit is.

Ohm's Law applies to every single circuit.

What's more, the more simple the circuit, the more easy it is to inspect before applying power.

There simply is no valid excuse for suggesting the wiring not be inspected before connecting power.

Okay.

You win.

I just ordered (4) four battery fuses this morning. (175 amp) Individual circuits are already fused.

I do have a 400 watt inverter hooked up, but I usually only run a fan, fluorescent light, and charge my phone and laptop with it (and a 1500 watt as a spare which if I use it with a heavy load will be the only thing running)

On my boat, most all the wiring is visible near the switch/fuse boxes. The wiring to the lights (running and cabin) is all that isn't

[Stu Jackson]

Originally Posted by Bigjim

FYI, the diagram I posted was from the owners manual. There are no docs from the PO. So your guess is as good as mine.

Fascinating.

Could it be that you might be getting closer to understanding why suggestions to stop guessing may be appropriate?

[btrayfors]

Originally Posted by thomm225

Okay.
........
I just ordered (4) four battery fuses this morning. (175 amp) Individual circuits are already fused. .............

175 amp fuses are likely to be Mega fuses. These are NOT suitable for connection directly to house batteries, because their ampere interrupt capacity (AIC) isn't high enough.

Only fuses suitable for direct connection to batteries are: Class-T, ANL, or MRBF (terminal) types. These all have AIC's in excess of the min. 5000 amps.

Bill

[thomm225]

Originally Posted by btrayfors

175 amp fuses are likely to be Mega fuses. These are NOT suitable for connection directly to house batteries, because their ampere interrupt capacity (AIC) isn't high enough.

Only fuses suitable for direct connection to batteries are: Class-T, ANL, or MRBF (terminal) types. These all have AIC's in excess of the min. 5000 amps.

Bill

Thanks. I'll switch those out.

Didn't realize they were what we call fast blow.

I may still hook one up (if they can't cancel the order) and see if it blows. Most of my loads are quite low current......5-10 amps per switch. (I know about the initial surge on some circuits)

[rwidman]

Originally Posted by thomm225

......... Haven't you ever shorted your car battery out with a wrench? .................

I knew not to do that before I was old enough to drive a car. And that was back when most car electrical systems were six volt!

So the answer is "no".

[btrayfors]

Originally Posted by thomm225

Thanks. I'll switch those out.

Didn't realize they were what we call fast blow.

I may still hook one up (if the can't cancel the order) and see if it blows. Most of my loads are quite low current......5-10 amps per switch. (I know about the initial surge on some circuits)

Issue isn't fast blow vs. slow blow, nor is it the actual loads attached. The issue is what could happen if there were a direct short in the circuit, the fuse blew OK, but it blew in a CLOSED condition, e.g., welded itself and passed current as if it weren't there at all.

That's why ABYC calls for an AIC of at least 5,000 amps for any fuse or circuit protection device (CPD) attached directly to a large battery source. In a full shorted condition, batteries are capable of delivering HUGE amp currents which could cause meltdowns, fires, explosions, etc.

One more caution when ordering, e.g., ANL fuses. Be advised that ANL fuses and fuseholders are not all created equal. Some of those which are very common in the automotive world (e.g., in high power audio circuits) really are not suitable for marine applications. You're best advised to use well-known and reliable marine suppliers, like Blue Sea Systems for both holders and fuses.

Bill

[thomm225]

Originally Posted by rwidman

I knew not to do that before I was old enough to drive a car. And that was back when most car electrical systems were six volt!

So the answer is "no".

We all know not to do that but it can and will happen when you are young and in a hurry to do a repair.

I've caused some pretty nice arcs from car batteries but no where near as strong (and loud) as discharging the high voltage section of radar transmitters with a shorting bar before doing repairs

High voltage to CRT's can also give a nice arc and ruin your day if you get hit by it.

I got 115 AC/400 hz in the mouth once. I had some solder in my mouth and was soldering in the dark. The system was off but the solder hit the side of the power switch where the power was. It didn't hurt my mouth but did hurt down my neck. This back in the 70's

[thomm225]

Originally Posted by btrayfors

Issue isn't fast blow vs. slow blow, nor is it the actual loads attached. The issue is what could happen if there were a direct short in the circuit, the fuse blew OK, but it blew in a CLOSED condition, e.g., welded itself and passed current as if it weren't there at all.

That's why ABYC calls for an AIC of at least 5,000 amps for any fuse or circuit protection device (CPD) attached directly to a large battery source. In a full shorted condition, batteries are capable of delivering HUGE amp currents which could cause meltdowns, fires, explosions, etc.

One more caution when ordering, e.g., ANL fuses. Be advised that ANL fuses and fuseholders are not all created equal. Some of those which are very common in the automotive world (e.g., in high power audio circuits) really are not suitable for marine applications. You're best advised to use well-known and reliable marine suppliers, like Blue Sea Systems for both holders and fuses.

Bill

Got it, I'll go with the AIC

I've had a battery blow up before on start up in a car of mine once. You wouldn't want to be near it

[Sailmonkey]

Originally Posted by thomm225

Got it, I'll go with the AIC

I've had a battery blow up before on start up in a car of mine once. You wouldn't want to be near it

AIC means amps interrupt capacity, it's a rating, not a fuse type.

My favorite for battery fusing are these

https://www.bluesea.com/products/519...k_-_30_to_300A

[Scot McPherson]

The statement earlier in the thread that ABYC standards are voluntary may be true, but they are developed for a reason, and there is a reason why so many technicians and surveyors are ABYC certified. It sets a standard of safety and reliability and baseline knowledge. ABYC standards are not so far an above the minimum coast guard regulations. They are an improvement. Yes voluntary, but highly recommended.


My boat is an old boat, and the wiring in it was "legal" but not up to abyc standards. After checking for continuity and shorts all over the place to assure it was "safe" to plug in, it only took a few minutes of being plugged into shore power for the fuse panel to get warm to the touch. If the panel was getting warm, god knows how hot the wires themselves were getting.


When I ripped the old panel off and I saw 14 guage carrying the 30 amp trunk and and 16 gauge wire carrying 20 amps branches of 120v AC, I was shocked. I spent about $500 for a new blue sea breaker panel, new shore power receptacle, GFCI Outlets, and about 50 ft of three colors of marine stranded wire (black, white and green) at 12 guage, and 3 ft of 10 guage for the 30 amp main trunk between the shore power and the 30 amp breaker main.


That's ABYC compliant, and all the wires stay cool to the touch right up to tripping a breaker. That's the way it's supposed to be, it prevents fires and prevents future shorts caused by degrading shielding allowing arcs between parallel wires.


Don't scoff at the standards, they are there for a good reason. You can chose to ignore them if you like, but that is not a decision to be taken lightly and really should be taken ONLY IF you REALLY know what you are doing.

[ramblinrod]

Originally Posted by Scot McPherson

The statement earlier in the thread that ABYC standards are voluntary may be true, but they are developed for a reason, and there is a reason why so many technicians and surveyors are ABYC certified. It sets a standard of safety and reliability and baseline knowledge. ABYC standards are not so far an above the minimum coast guard regulations. They are an improvement. Yes voluntary, but highly recommended.


My boat is an old boat, and the wiring in it was "legal" but not up to abyc standards. After checking for continuity and shorts all over the place to assure it was "safe" to plug in, it only took a few minutes of being plugged into shore power for the fuse panel to get warm to the touch. If the panel was getting warm, god knows how hot the wires themselves were getting.


When I ripped the old panel off and I saw 14 guage carrying the 30 amp trunk and and 16 gauge wire carrying 20 amps branches of 120v AC, I was shocked. I spent about $500 for a new blue sea breaker panel, new shore power receptacle, GFCI Outlets, and about 50 ft of three colors of marine stranded wire (black, white and green) at 12 guage, and 3 ft of 10 guage for the 30 amp main trunk between the shore power and the 30 amp breaker main.


That's ABYC compliant, and all the wires stay cool to the touch right up to tripping a breaker. That's the way it's supposed to be, it prevents fires and prevents future shorts caused by degrading shielding allowing arcs between parallel wires.


Don't scoff at the standards, they are there for a good reason. You can chose to ignore them if you like, but that is not a decision to be taken lightly and really should be taken ONLY IF you REALLY know what you are doing.

100% Agreement!

The only people that should entertain deviation form applicable marine standards, are those who no so much about marine electrical wiring, that they understand why the standards are as they are, and can make an educated decision to deviate.

When I deviate from ABYC standards or good practice, it automatically flashes in my head, "Can I justify this action, if challenged in court, should something, even completely unrelated, go south?"

So before I could possibly connect a shore power cord or a battery to a derelict boat, all of the alarm bells would go off, I would set the power source down, and inspect the wiring. ABYC doesn't require it; but sound practice does.

[thomm225]

Originally Posted by Sailmonkey

AIC means amps interrupt capacity, it's a rating, not a fuse type.

My favorite for battery fusing are these

https://www.bluesea.com/products/519...k_-_30_to_300A

Yeah, okay. (that other guy mentioned that)

Thanks for the link.

[ramblinrod]

Originally Posted by thomm225

We all know not to do that but it can and will happen when you are young and in a hurry to do a repair.

I've caused some pretty nice arcs from car batteries but no where near as strong (and loud) as discharging the high voltage section of radar transmitters with a shorting bar before doing repairs

High voltage to CRT's can also give a nice arc and ruin your day if you get hit by it.

I got 115 AC/400 hz in the mouth once. I had some solder in my mouth and was soldering in the dark. The system was off but the solder hit the side of the power switch where the power was. It didn't hurt my mouth but did hurt down my neck. This back in the 70's

And you object to safe wiring recommendations?

I'm not shocked! ;-)

FYI, in the 70s and 80's solder was typically 60% lead or higher.

Lead accumulates in your body over your lifetime and can lead to a variety of adverse medical conditions, including neurological damage.

The most common / prolific method of entry is ingestion.

In 2010, the state of California lead (har har) the way to mandating the reduction in the use of lead in brass plumbing products used for domestic water, from a maximum of 4% to only 0.25%, due to the risk of lead leaching into drinking water.

Direct application orally. Hmmm. Have you had your blood levels checked?