I've not seen one go bad but you can try disconnecting it temporarily. Do you have a galvanic isolator?
alternative charging options?
- Thread starter Justin_NSA
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I've not seen one go bad but you can try disconnecting it temporarily. Do you have a galvanic isolator?
I think that diode or surge supressor would trip the GFCI both in the water or on land if it was "bad".. But you said you dont trip on land.
Curious is you can just plug into a dock neighbors receptacle that you know works.. Ie, plug into a neighbors plug that has the same GFCI setup but does not trip on your neighbors boat.
I do not. I read your article, but I wasn't sure it would make a difference in my case. I will disconnect the surge arrester and see if it helps.
I had replaced the breaker early in my ownership and reused the CG751. The case was cracked and a lug was loose. The new paneltronics said it requires the 281-001. I can't find one anywhere.
It is disturbing that nothing trips sitting on the trailer in the yard
I have tried to plug in to different pedestals and it still trips the pedestal GFCI
How are you connecting when in the yard vs at the slip? different set of cables or splitters/combiners/3 prong circular to 3 prong "household outlet" converter...???
Assuming the GFCI outlets on the hard and at the dock are both identical and both of them work..
Since you trip in the water on both your slip rec. and a neighbors slip rec (which does not trip his boat), we can assume that you have some sort of ground fault leakage.
Assuming your that your on the hard GFCI was working correctly and it does not trip, this would say that you do NOT have leakage from the AC hot to green in the boat wiring or AC devices. If you did have a boat wiring ground fault, the on the hard GFCI would also trip. It would trip because the green ground wire is hooked up in the on the hard setup so would have provided a path for the ground fault to leak and then trip the GFCI. This of course assumes the on the hard GFCI does work and the green safety wire is also hooked up correctly for the on the hard source.
If all the above is true and you only trip when the boat is in the water, this would imply that your leakage that is setting off the GFCI is through the water and not the green wire. The leakage from your boat to the water could either on the AC side but it could also be from a 12 volt DC wire somehow making contact with the water..
You have one more problem with your current meter test. If the GFCI trips and disconnects the AC, how do you measure any AC current? Maybe you will have to temporarilly remove the GFCI socket and replace it with a non GFCI socket.
If you are able to measure AC current (disable the GFCI), and if the boat is on the water,
clamp around hot and neutral only - should show some current as this is what is tripping the GFCI
Clamp on green only - if this shows zero current, the ground fault leakage is going through the water.
Since you trip in the water on both your slip rec. and a neighbors slip rec (which does not trip his boat), we can assume that you have some sort of ground fault leakage.
Assuming your that your on the hard GFCI was working correctly and it does not trip, this would say that you do NOT have leakage from the AC hot to green in the boat wiring or AC devices. If you did have a boat wiring ground fault, the on the hard GFCI would also trip. It would trip because the green ground wire is hooked up in the on the hard setup so would have provided a path for the ground fault to leak and then trip the GFCI. This of course assumes the on the hard GFCI does work and the green safety wire is also hooked up correctly for the on the hard source.
If all the above is true and you only trip when the boat is in the water, this would imply that your leakage that is setting off the GFCI is through the water and not the green wire. The leakage from your boat to the water could either on the AC side but it could also be from a 12 volt DC wire somehow making contact with the water..
You have one more problem with your current meter test. If the GFCI trips and disconnects the AC, how do you measure any AC current? Maybe you will have to temporarilly remove the GFCI socket and replace it with a non GFCI socket.
If you are able to measure AC current (disable the GFCI), and if the boat is on the water,
clamp around hot and neutral only - should show some current as this is what is tripping the GFCI
Clamp on green only - if this shows zero current, the ground fault leakage is going through the water.
I went out to the boat tonight, The pedestal GFCI was tripped again. I removed the surge arrestor from behind the main AC breaker and powered it back up. Left it for 2 hours while I helped a guy haul his boat out on the crane. So far it hasn't tripped, but it can be hours or days before it does. Here is a pic of the component. It looks like there might be evidence of heat, he says, wishing it were true.
John - I think it is a form of MOV (metal oxide varistor) - not a diode... they are two back to back diodes with couple hundred volts breakdown voltages
If that part were bad, you would be blowing the GFCI on the hard.. But I understand that never happens.
It goes between green (earth ground) and white (neutral) and the voltage between these two nodes is never very high (or should never be very high anyhow).
Since that part normally does not see any voltage bias, you could simply measure the resistance on the two leads using an ohm meter. Measure it one way.. then swap the leads and measure it again. FYI, if that part was ever overstressed, the failed part could look like a low impedance and then would cause a problem. But as mentioned, it would cause a problem on the hard if that GFCI (and green earth hookup) was working correctly.
FYI, lets say that at very worse case, you get 3 volts RMS between those two wires (green and white). To get 5 ma, the resistance would have to be less than 600 ohms. My guess is that if you measrure the resistance, you will see maybe 1000 times that value (guess.. but I think it would be WAY higher..).
This all is assuming that every time you hook up to GFCI, you are the only load hooked up and that a string of slips are not served by one GFCI circuit.
It goes between green (earth ground) and white (neutral) and the voltage between these two nodes is never very high (or should never be very high anyhow).
Since that part normally does not see any voltage bias, you could simply measure the resistance on the two leads using an ohm meter. Measure it one way.. then swap the leads and measure it again. FYI, if that part was ever overstressed, the failed part could look like a low impedance and then would cause a problem. But as mentioned, it would cause a problem on the hard if that GFCI (and green earth hookup) was working correctly.
FYI, lets say that at very worse case, you get 3 volts RMS between those two wires (green and white). To get 5 ma, the resistance would have to be less than 600 ohms. My guess is that if you measrure the resistance, you will see maybe 1000 times that value (guess.. but I think it would be WAY higher..).
This all is assuming that every time you hook up to GFCI, you are the only load hooked up and that a string of slips are not served by one GFCI circuit.
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I read you Walt. The good behavior when on the hard might also be that it just sits there static too, ut it does support your statements. I'm grasping at straw now. A tester may or may not help. It's possible that the circuit is hovering just below the fault threshold and something pushes it over. A tester might see this. I'll be interested to see if it is tripped next time I go out.
Intermittent, non-inducible (?) problems are really frustrating
Intermittent, non-inducible (?) problems are really frustrating
Yup. And 99% of all Intermittent eletrical issues are connections, somewhere.
Good luck.
I think the AC meter clamp test from Maine Sail will be interesting.. If the intermittent issue is from being close to a threshold, I think you would be able to measure that as long as the instrument can read resolution in the ma range.
Little bit interesting to note how those instruments work. When you run current through a wire, it creates a magnetic field and the clamp instrument measures that magnetic field.
So if you just clamp on the black wire, it that would indicate how much current the boat is using.
If I have two wires running next to each other and the currents are in opposite direction and in phase, the magnetic fields cancel each other so you measure zero current. If one of these wires now has slightly less current, the magnetic fields dont exactly cancel so what you are measuring is the difference in current between the two wires. So if you clamp on the black and white wires, the current in each should be opposite and identical and you would read zero. But if there was some leakage either to the green wire or somehow to the water, the black and white would not have the same current and you could read this.
Since the instrument is just reading magnetic field inside the clamp, if the sum of currents going one way is equal to the sum of currents going the other way, the instrument will read zero current. The interesting thing about this is that you can have a ground faul where half the return current is on the green wire and half on the white which is a really bad ground fault but the clamp meter around all three wires reads zero. At a marina, someone would just clamp on all three wires (easiest) and while this wont tell you if the green wire has current on it, measuring any current on all three wires means that the leakage is going into the water. (safety issue).
Clamp on black only - this tells the AC current draw of the boat
Clamp on black and white only If this is zero, you have no leakage and no problem.. If its not zero, you have leakage and its above the GFCI trip level, trips.
Clamp on green only. If you measured leakage on the black and wire wires but no current on the green wire, the leakage current is going into the water. If the leakage current is on the green wire, the reading for the black and white wire couple should equal the current on the green side.
Clamp on all three wires. Zero current only means that you dont have current leaking into the water. If you do have current leaking into the water, the clamp on all three wires will measure this. But.. you can have a ground fault leaking current to the green wire in the cable and you can not measure this with the clamp on all three wires.
And.. I could have something wrong in there. What you measure will be interesting..
Little bit interesting to note how those instruments work. When you run current through a wire, it creates a magnetic field and the clamp instrument measures that magnetic field.
So if you just clamp on the black wire, it that would indicate how much current the boat is using.
If I have two wires running next to each other and the currents are in opposite direction and in phase, the magnetic fields cancel each other so you measure zero current. If one of these wires now has slightly less current, the magnetic fields dont exactly cancel so what you are measuring is the difference in current between the two wires. So if you clamp on the black and white wires, the current in each should be opposite and identical and you would read zero. But if there was some leakage either to the green wire or somehow to the water, the black and white would not have the same current and you could read this.
Since the instrument is just reading magnetic field inside the clamp, if the sum of currents going one way is equal to the sum of currents going the other way, the instrument will read zero current. The interesting thing about this is that you can have a ground faul where half the return current is on the green wire and half on the white which is a really bad ground fault but the clamp meter around all three wires reads zero. At a marina, someone would just clamp on all three wires (easiest) and while this wont tell you if the green wire has current on it, measuring any current on all three wires means that the leakage is going into the water. (safety issue).
Clamp on black only - this tells the AC current draw of the boat
Clamp on black and white only If this is zero, you have no leakage and no problem.. If its not zero, you have leakage and its above the GFCI trip level, trips.
Clamp on green only. If you measured leakage on the black and wire wires but no current on the green wire, the leakage current is going into the water. If the leakage current is on the green wire, the reading for the black and white wire couple should equal the current on the green side.
Clamp on all three wires. Zero current only means that you dont have current leaking into the water. If you do have current leaking into the water, the clamp on all three wires will measure this. But.. you can have a ground fault leaking current to the green wire in the cable and you can not measure this with the clamp on all three wires.
And.. I could have something wrong in there. What you measure will be interesting..
Speaking off the top of my head (which can be dangerous), I believe that an MOV is basically an open circuit until you reach a certain voltage across the two leads, then it suddenly conducts with a very low resistance. Their most common purpose is to eat up unexpected voltage spikes in power supply circuits for sensitive equipment. They are usually round & flat. They often show two small rods on the flat surfaces. They are often, but not always blue or green.
I would think that the best way to test them would be by attaching them to a variable voltage power supply that has a current limiting feature & watching the ammeter for a sudden spike. A homebrew test might be to apply various voltages with a small amperage fast-blow fuse in series. When the fuse pops, you found the trip voltage.
A zener diode has the same function as I just described above, except that when it conducts, it only conducts in one direction. They are commonly used to bleed off excess amperage from unregulated charging systems in older British motorcycles. Higher voltage versions are used in other power control circuits. A zener diode often looks like a regular diode. Unless you look up the part number that is written on the side of the barrel, you don't know if you have a zener or not.
The MOV needs to be out of the circuit to perform these tests. The same is normally true when testing diodes.
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In case anyone might be following my GFCI tripping problem; Removing the surge arrestor did not make any difference. The GFCI still trips randomly. Every time I go out to the boat it is tripped.
The good news is my leakage detector finally arrived! So now maybe I have a solid way to trace down this issue. I hope to post success some day!
The good news is my leakage detector finally arrived! So now maybe I have a solid way to trace down this issue. I hope to post success some day!
I hope to John. I checked mine while the GFCI was staying set and I have a small leak between hot and neutral I need to track down. Maybe my neighbors will let me do a quick test on their boats. Unfortunately most have hauled them out already. At least mine will be fixed by Spring. I may try and test the dock posts anyway.