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#1
posted to rec.boats.electronics
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More Breaker Panel Mess
So are you complaining that the AC ground and DC negative are both connected
to the boats ground or where they're connected? "Larry" wrote in message ... Marc wrote in news:ufm1p1h2l7qr8s8vs3vbso6j1so1l3apgr@ 4ax.com: Having disconnected and labeled all the 12 V wiring, the 110 AC is now visable. It appears that all the AC ground wires (green) are run to a common buss. But , then, the AC Ground buss is connected with a 6 ga. wire to the DC negative buss. This doesn't seem right to me. Is it? They do this to insure your engine, underwater propulsion gear and everything hooked to the DC ground system is connected to every other stupid boat and the marina's big earth ground system, making one HUGE battery out of those zincs you can't figure out why they disappear so fast. There's absolutely NO reason why the independent DC system should be connected to the AC ground bus I know of. Ours isn't. I'll be damned if I'd pay with MY zincs to protect your prop because my zincs are hooked through the AC wiring ground to your zincs..... Oh, hooked up like that, too, your zincs are protecting the whole electrical system of HIS marina any place it touches the water or makes contact with the earth. Aren't you being, inadvertently, nice....(c; |
#2
posted to rec.boats.electronics
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More Breaker Panel Mess
"johnhh" wrote in
: So are you complaining that the AC ground and DC negative are both connected to the boats ground "Boats ground"? What's that? The boat is made of PLASTIC, an insulator. It has no "ground". It has a negative battery bus. It has an AC supply ground connected to the shore power ground system. What's the "boats ground"? I hear this a lot. It doesn't exist. The battery negative bus has no relationship, whatsoever, to the AC shore power ground as the two systems are totally isolated from each other unless there is something wrong with your battery charger, dual-voltage fridge or other AC/DC components. Touching the AC shore grounded appliance, already hooked to AC shore ground, with one hand and touching the engine block connected to the sea and DC ground bus results in no hazard...unless the AC shore ground is defective PLUS the appliance or device is defective. Touching an AC grounded device with one hand and a defective 2-wire toaster with the hot lead of the AC line hooked to its metal case has the SAME SHOCK as touching the DC ground bus hooked to the engine block....unless, of course, the boat has a proper GFI that should, but is not, required aboard the boat....just like proper NEC-approved breaker panels are not. (A bunch of little plastic breakers on a plastic panel screwed into a flammable wooden box made of some exotic, expensive wood is NOT up to the National Electric Code of the USA or any country with any brains. AC and DC panels in boats are made that way to SAVE MANUFACTURERS MONEY. They are NOT "safe", from fire (flammable) or explosion (not sealed against fumes) at all! Ok, back to the buses connected together for some stupid reason..... If the DC bus hooked to the zincs by virtue of the DC bus being connected to the engine block....is connected directly to the AC bus ground back to shore power ground through the boat's impressive yellow shore cable, this connects the boat's zincs STRAIGHT TO THE BOTTOM OF THE HARBOR...not to mention every other boat wired this stupid way. YOUR zincs are hooked to HIS underwater metal parts through the common-connected AC shore power ground wires. So? What happens now?........(you ask)..... Ever notice the metal conduit hanging loose under every dock on every marina in the country? See how it hangs into the water? If I hook MY zincs to that metal conduit (by the AC shore power ground wire from the boat with the DC negative bus hooked to AC shore power ground), MY zinc will fizz away protecting the rotting plating on that sagging conduit, every little ground wire touching anything conductive hooked to the water, and even the ground rod back at the feed point from the power company! Isn't that nice of me? Is it any wonder some people are going through those amazingly-expensive zincs at an alarming rate in your marina? Zincs protect what they are CONNECTED to. They are a virual shorted battery, the zinc one plate, any metal part making connections with the water the other plate and seawater as the electrolyte. In order for the battery to DISCHARGE, eating the zinc, it has to have a DIRECT DC PATH from the zinc to that plate. Unhook the path, you've opened the shorted battery circuit. The only battery plate the UNHOOKED boat makes a battery with is the metal part the zinc is mounted on and is protecting, not every neighboring boat connected to the AC power shore ground. Every AC device in the boat, with, of course, the exception of insulated, UL-approved, appliances-electronics-doubleinsulated drills-etc....should be hooked for safety to the SHORE GROUND, to prevent the AC line from appearing on the metal cabinet parts of it. Of course, it would be nice if the damned AC panel, ITSELF, on pleasure boats were so connected. They're not. Look into the wooden box. Metal breaker panel hooked to green wire? Not most. If you disconnect the DC negative bus from the AC Shore Ground green wire, you measure the DC potential caused by the zincs...the electroplating voltage trying to destroy the zincs. It CAN'T have any AC voltage between the Shore Ground hooked to a ground rod somewhere and the DC ground bus hooked to the engine block....doesn't wash. |
#3
posted to rec.boats.electronics
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More Breaker Panel Mess
So you're saying not to ground the AC ground at the boat, but to rely on the
shore ground? Everything I've read says you must ground it at the boat as a safety precaution against faulty grounding at the dock. Did I misunderstand something? I can't (conveniently) isolate my house DC from ground since I have a non-isolated ground alternator. Don't SSB antennas need to be grounded? Do the radios isolate the antenna ground from DC ground? "Larry" wrote in message ... "johnhh" wrote in : So are you complaining that the AC ground and DC negative are both connected to the boats ground "Boats ground"? What's that? The boat is made of PLASTIC, an insulator. It has no "ground". It has a negative battery bus. It has an AC supply ground connected to the shore power ground system. What's the "boats ground"? I hear this a lot. It doesn't exist. The battery negative bus has no relationship, whatsoever, to the AC shore power ground as the two systems are totally isolated from each other unless there is something wrong with your battery charger, dual-voltage fridge or other AC/DC components. Touching the AC shore grounded appliance, already hooked to AC shore ground, with one hand and touching the engine block connected to the sea and DC ground bus results in no hazard...unless the AC shore ground is defective PLUS the appliance or device is defective. Touching an AC grounded device with one hand and a defective 2-wire toaster with the hot lead of the AC line hooked to its metal case has the SAME SHOCK as touching the DC ground bus hooked to the engine block....unless, of course, the boat has a proper GFI that should, but is not, required aboard the boat....just like proper NEC-approved breaker panels are not. (A bunch of little plastic breakers on a plastic panel screwed into a flammable wooden box made of some exotic, expensive wood is NOT up to the National Electric Code of the USA or any country with any brains. AC and DC panels in boats are made that way to SAVE MANUFACTURERS MONEY. They are NOT "safe", from fire (flammable) or explosion (not sealed against fumes) at all! Ok, back to the buses connected together for some stupid reason..... If the DC bus hooked to the zincs by virtue of the DC bus being connected to the engine block....is connected directly to the AC bus ground back to shore power ground through the boat's impressive yellow shore cable, this connects the boat's zincs STRAIGHT TO THE BOTTOM OF THE HARBOR...not to mention every other boat wired this stupid way. YOUR zincs are hooked to HIS underwater metal parts through the common-connected AC shore power ground wires. So? What happens now?........(you ask)..... Ever notice the metal conduit hanging loose under every dock on every marina in the country? See how it hangs into the water? If I hook MY zincs to that metal conduit (by the AC shore power ground wire from the boat with the DC negative bus hooked to AC shore power ground), MY zinc will fizz away protecting the rotting plating on that sagging conduit, every little ground wire touching anything conductive hooked to the water, and even the ground rod back at the feed point from the power company! Isn't that nice of me? Is it any wonder some people are going through those amazingly-expensive zincs at an alarming rate in your marina? Zincs protect what they are CONNECTED to. They are a virual shorted battery, the zinc one plate, any metal part making connections with the water the other plate and seawater as the electrolyte. In order for the battery to DISCHARGE, eating the zinc, it has to have a DIRECT DC PATH from the zinc to that plate. Unhook the path, you've opened the shorted battery circuit. The only battery plate the UNHOOKED boat makes a battery with is the metal part the zinc is mounted on and is protecting, not every neighboring boat connected to the AC power shore ground. Every AC device in the boat, with, of course, the exception of insulated, UL-approved, appliances-electronics-doubleinsulated drills-etc....should be hooked for safety to the SHORE GROUND, to prevent the AC line from appearing on the metal cabinet parts of it. Of course, it would be nice if the damned AC panel, ITSELF, on pleasure boats were so connected. They're not. Look into the wooden box. Metal breaker panel hooked to green wire? Not most. If you disconnect the DC negative bus from the AC Shore Ground green wire, you measure the DC potential caused by the zincs...the electroplating voltage trying to destroy the zincs. It CAN'T have any AC voltage between the Shore Ground hooked to a ground rod somewhere and the DC ground bus hooked to the engine block....doesn't wash. |
#4
posted to rec.boats.electronics
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More Breaker Panel Mess
"johnhh" wrote in
: So you're saying not to ground the AC ground at the boat, but to rely on the shore ground? Everything I've read says you must ground it at the boat as a safety precaution against faulty grounding at the dock. Did I misunderstand something? The boat is made of PLASTIC. You cannot ground the fiberglass. If you have a steel hull, I still wouldn't connect the green wire to it. It is already "grounded" through the seawater. You'd just add to your galvanic action problem. You may not be able to isolate it as the grounded equipment is hooked to the hull in lots of places, anyways. Fiberglass boats are being discussed. All AC grounds are to be connected to shore power "ground". This insures you get knocked on your ass if you touch AC hot and the grounded fridge case. But, that's the way they want it. Buy a plastic cased fridge, problem solved. The battery charger should have its DC circuit isolated from its AC circuit. If it's not, I wouldn't buy it. The + and - charging terminals should be totally isolated from the power-line- grounded case. If you tie the "faulty ground" at the dock, let's say it's open from corrosion or the wire is busted, connected or not to DC ground in the boat...it's still open. If the plug is wired wrong, the AC box is still grounded to ground. You'll get knocked on your ass plugging your grounded plug in if it doesn't explode in your hand before the breaker trips. Grounding the hot AC line through the faulty hot-connected-to- green-wire-to-the-boat absurd scenario in the DC to AC interconnected ground scenario only results in a big flash as the AC current has a direct path to ground through the engine block/propshaft, tripping the breaker I hope unless some other absurd scenario has it bypassed.... I'll be absurd, too. Every boater should have a ground detector built right into the AC breaker panel! |
#5
posted to rec.boats.electronics
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More Breaker Panel Mess
Jeez Larry, I didn't say anything about grounding anything to a plastic
hull. I also did not say that the AC ground should not be grounded at the shore side. I said that everything I have read says it should also be grounded at the boat end. Just like that grounding rod outside my wood house. "Larry" wrote in message ... "johnhh" wrote in : So you're saying not to ground the AC ground at the boat, but to rely on the shore ground? Everything I've read says you must ground it at the boat as a safety precaution against faulty grounding at the dock. Did I misunderstand something? The boat is made of PLASTIC. You cannot ground the fiberglass. If you have a steel hull, I still wouldn't connect the green wire to it. It is already "grounded" through the seawater. You'd just add to your galvanic action problem. You may not be able to isolate it as the grounded equipment is hooked to the hull in lots of places, anyways. Fiberglass boats are being discussed. All AC grounds are to be connected to shore power "ground". This insures you get knocked on your ass if you touch AC hot and the grounded fridge case. But, that's the way they want it. Buy a plastic cased fridge, problem solved. The battery charger should have its DC circuit isolated from its AC circuit. If it's not, I wouldn't buy it. The + and - charging terminals should be totally isolated from the power-line- grounded case. If you tie the "faulty ground" at the dock, let's say it's open from corrosion or the wire is busted, connected or not to DC ground in the boat...it's still open. If the plug is wired wrong, the AC box is still grounded to ground. You'll get knocked on your ass plugging your grounded plug in if it doesn't explode in your hand before the breaker trips. Grounding the hot AC line through the faulty hot-connected-to- green-wire-to-the-boat absurd scenario in the DC to AC interconnected ground scenario only results in a big flash as the AC current has a direct path to ground through the engine block/propshaft, tripping the breaker I hope unless some other absurd scenario has it bypassed.... I'll be absurd, too. Every boater should have a ground detector built right into the AC breaker panel! |
#6
posted to rec.boats.electronics
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More Breaker Panel Mess
On Sat, 03 Dec 2005 18:54:28 -0500, Larry wrote:
"johnhh" wrote in : So are you complaining that the AC ground and DC negative are both connected to the boats ground "Boats ground"? What's that? The boat is made of PLASTIC, an insulator. It has no "ground". It has a negative battery bus. It has an AC supply ground connected to the shore power ground system. What's the "boats ground"? Not everbody has a "Tupperware" boat Larry. Some of us have steel boats. I sincerely hope that your philosophy changes for these. The best problem that I found on a boat was the following. Steel boat in at a dock connected to 240v shoreline. Boat was pressure washed and sparks were seen when the lance touched the hull. I was asked to check it out. Finally found that the hull was sitting at 24v dc above shore ground. Went searching and found that the metal end cover on the charger was touching an uninsulated crimp lug. The DC -ve was not connected to the hull. If the system had been installed correctly this would not have happened. I am glad that my Steel hull was not mored nearby!!! Richard Nb "Pound Eater" Parkend G+S |
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