For the last year or so, my Mariner Depth Meter has done the following: Worked fine, works sometime, fluctuates between 160 and 0, just stays on 0. I sent it in, had it checked, all OK. Replaced sending unit with out any change in operation. Sitting at the dock, with unit on, needle moves approx 20 feet when I plug/unplug shore power, even if SP is tripped/untripped. Here is the wierd part. My boat has an outboard with electric start. When the motor and the cable that runs to the battery is removed from the boat, the DM works fine. Also, with the motor on the boat, sitting at the dock, the needle usually, not always, goes to 120 and slowly drifts down to 0, back to 120 etc. But, if the motor is not touching the water, it reads 60, the proper depth. Anyone have any ideas? John
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Gremlins
You've got a bad ground/ground path somewhere. Is your O/B alt. grounding out or something? Check all connectors, not only those on the depth circuit. Good Luck, AD
You've got a bad ground/ground path somewhere. Is your O/B alt. grounding out or something? Check all connectors, not only those on the depth circuit. Good Luck, AD
Check shore power neutral
John, Make sure the shore power AC neutral wire (green wire) IS NOT connected to the DC negative (ground). A lot of people confuse AC neutral with DC ground but they are not the same and can be dangerous if interconnected and a piece of AC equipment fails. That might explain the shore power issue. Not sure on the issue with the motor but I bet Adam is correct and there is a loose connection somewhere on the negative side of the board. After you make sue the alternator is okay, I would check the battery connections and the bus bars first, and then work around to the individual circuits. What you can do is disconnect each circuit one at a time from the negative bus and see if the problem goes away. Probably not related to your particular issue, but I have seen my Moor Electronics depth gauge do something similar, but it only happens if the thru-hull is leaking. Anyone else ever have this problem? Best of luck slaying the gremlins. They can be hardy little buggers. Bob s/v Simple Dreams Chicago
John, Make sure the shore power AC neutral wire (green wire) IS NOT connected to the DC negative (ground). A lot of people confuse AC neutral with DC ground but they are not the same and can be dangerous if interconnected and a piece of AC equipment fails. That might explain the shore power issue. Not sure on the issue with the motor but I bet Adam is correct and there is a loose connection somewhere on the negative side of the board. After you make sue the alternator is okay, I would check the battery connections and the bus bars first, and then work around to the individual circuits. What you can do is disconnect each circuit one at a time from the negative bus and see if the problem goes away. Probably not related to your particular issue, but I have seen my Moor Electronics depth gauge do something similar, but it only happens if the thru-hull is leaking. Anyone else ever have this problem? Best of luck slaying the gremlins. They can be hardy little buggers. Bob s/v Simple Dreams Chicago
Sounds Familiar
My depth was acting goofy for a while and I went through all of the things that the other guys were talking about, never did find any problems wiring wise. On mine, it was acting up only when I was in my slip, so naturally, I associated it with a wiring/ground problem. I'll cut this short. One of my dock mates told me that the owner of the boat that was previously in my present slip accidentally dropped a bunch of CD's overboard and that they were never recovered. I contacted the factory and talked to one of their Tech's. After we hashed it over, he agreed that the CD's could be reflecting erratic soundings causing the depth to act up. May not be your problem, but this one drove me crazy trying to find all other solutions. Luck with it!
My depth was acting goofy for a while and I went through all of the things that the other guys were talking about, never did find any problems wiring wise. On mine, it was acting up only when I was in my slip, so naturally, I associated it with a wiring/ground problem. I'll cut this short. One of my dock mates told me that the owner of the boat that was previously in my present slip accidentally dropped a bunch of CD's overboard and that they were never recovered. I contacted the factory and talked to one of their Tech's. After we hashed it over, he agreed that the CD's could be reflecting erratic soundings causing the depth to act up. May not be your problem, but this one drove me crazy trying to find all other solutions. Luck with it!
A quick correction...
Bob, the green wire for shore power is GROUND, the nuetral wire will be WHITE, or possibly Grey. The green wire from shore power should be connected to the boats grounding grid, but the A.C. neutral (white) should be 'floating', that is, not connected to anything but the A.C. system. Other than that, I'd say the prior posters are correct, there's likely a grounding issue involved here that's causing the problem at hand. Don't assume that just because a wire is connected to the ground grid that it is truly grounded. Even a little tiny bit of corrosion can put enough resistance in the ground path to causes all sorts of 'weirdity'. Check and clean all of the connections and be sure to use a good anti-oxidant on all terminals and connections to lower the risk of corrosion induced resistance. Best of luck!
Bob, the green wire for shore power is GROUND, the nuetral wire will be WHITE, or possibly Grey. The green wire from shore power should be connected to the boats grounding grid, but the A.C. neutral (white) should be 'floating', that is, not connected to anything but the A.C. system. Other than that, I'd say the prior posters are correct, there's likely a grounding issue involved here that's causing the problem at hand. Don't assume that just because a wire is connected to the ground grid that it is truly grounded. Even a little tiny bit of corrosion can put enough resistance in the ground path to causes all sorts of 'weirdity'. Check and clean all of the connections and be sure to use a good anti-oxidant on all terminals and connections to lower the risk of corrosion induced resistance. Best of luck!
Men, the ground on an alternating current panel
doesn't do anything until a appliance or wire shorts. Then it can be a life saver until the breaker trips. Don't confuse AC ground with DC ground. The ground path for DC is vital for the proper operation of the accessory. With that said, a poor ground will still let your stuff run, sort of.
But 'running' doesn't mean 'working good'. A poor ground somewhere on the DC side is almost certainly the problem.
doesn't do anything until a appliance or wire shorts. Then it can be a life saver until the breaker trips. Don't confuse AC ground with DC ground. The ground path for DC is vital for the proper operation of the accessory. With that said, a poor ground will still let your stuff run, sort of.
But 'running' doesn't mean 'working good'. A poor ground somewhere on the DC side is almost certainly the problem.Fred, you're exactly right...
in an A.C. system, the ground wire is a 'non-current-carrying conductor'. It is only there to carry a 'fault current' in the event of catastrophic failure of the connected load. If you have ANY current flow or voltage on an A.C. ground conductor, something is seriously wrong! On the other hand, in a D.C. system, the ground wire is used to complete the path from the load to the source, this same conductor function is referred to as a NEUTRAL in an A.C. system. A confusing bit of nomenclature, I know, but the difference between the two is VERY important!
in an A.C. system, the ground wire is a 'non-current-carrying conductor'. It is only there to carry a 'fault current' in the event of catastrophic failure of the connected load. If you have ANY current flow or voltage on an A.C. ground conductor, something is seriously wrong! On the other hand, in a D.C. system, the ground wire is used to complete the path from the load to the source, this same conductor function is referred to as a NEUTRAL in an A.C. system. A confusing bit of nomenclature, I know, but the difference between the two is VERY important!
Thanks Jeff, and to freak out the novices
even more, the white wire that completes the path for alternating current, leaves the boat and then goes to a grounding rod device on shore. It stops in the dirt. How's that for weird? The neutral at your house (and all houses) ends in the dirt too, just below your power meter, and the ground, safety wire, is hooked to the same place. Those AC wires in the poles are all hot. (black)
even more, the white wire that completes the path for alternating current, leaves the boat and then goes to a grounding rod device on shore. It stops in the dirt. How's that for weird? The neutral at your house (and all houses) ends in the dirt too, just below your power meter, and the ground, safety wire, is hooked to the same place. Those AC wires in the poles are all hot. (black)
John, go through...
...all your connections. Pull them apart, rough up the connections then use a connection preservative such as DeOxit 5. As other posters have noted that even a good looking connection can be loose and/or dirty. Clean 'em all. You might also want to wipe down/clean up your electric panel and guages. Over time moisture may leave deposited crystalline material or good old-fashioned gunk that may leave a surface film able to serve as a conductor of sorts (these films also retain/attract moisture). To this end, don't forget to wipe down the top of the battery as this can also get accumulated amounts of wetted crytalline matter to create a small conductor between posts. Not unlike water, electricity will look for a path of least resistance/flow; so if you have a dodgey ground somewhere, the electricity may be finding ground through another source/connection. Regards, Adam
...all your connections. Pull them apart, rough up the connections then use a connection preservative such as DeOxit 5. As other posters have noted that even a good looking connection can be loose and/or dirty. Clean 'em all. You might also want to wipe down/clean up your electric panel and guages. Over time moisture may leave deposited crystalline material or good old-fashioned gunk that may leave a surface film able to serve as a conductor of sorts (these films also retain/attract moisture). To this end, don't forget to wipe down the top of the battery as this can also get accumulated amounts of wetted crytalline matter to create a small conductor between posts. Not unlike water, electricity will look for a path of least resistance/flow; so if you have a dodgey ground somewhere, the electricity may be finding ground through another source/connection. Regards, Adam
Thanks for the corrections, Jeff and Fred...
You are right, and I had my terminology wrong. I should have said "make sure the AC ground is not connected to the DC negative". Even though it carries no current under normal operating conditions, you don't want it hooked to DC if an AC circuit goes to ground. I found such a connection (or rather the surveyor did) on my boat before I bought it. First thing I corrected. Thanks for the correction, and sorry for the confusion. Bob
You are right, and I had my terminology wrong. I should have said "make sure the AC ground is not connected to the DC negative". Even though it carries no current under normal operating conditions, you don't want it hooked to DC if an AC circuit goes to ground. I found such a connection (or rather the surveyor did) on my boat before I bought it. First thing I corrected. Thanks for the correction, and sorry for the confusion. Bob
One more experience with Mariner
John, I now have problems with my depth meter fluctuating and will now check grounds etc. that are suggested. My problem previously was different- the needle was too close to the face and when it was in the sun, it would stick at different depths. I thought it was stactic electricity, but an old friend of mine who had an electonics business looked at it and it checked out ok, until he had it under a hot lamp and voila -- it stuck. He put in a small spacer ring and that problem was solved. Maybe check this clearance problem as well as the other suggestions on the circuit. Hope this helps.
John, I now have problems with my depth meter fluctuating and will now check grounds etc. that are suggested. My problem previously was different- the needle was too close to the face and when it was in the sun, it would stick at different depths. I thought it was stactic electricity, but an old friend of mine who had an electonics business looked at it and it checked out ok, until he had it under a hot lamp and voila -- it stuck. He put in a small spacer ring and that problem was solved. Maybe check this clearance problem as well as the other suggestions on the circuit. Hope this helps.
Does anyone know what the ABYC says...
about the A.C. ground being tied to the boat ground grid? Seems to me that all grounds should be tied together, both for safety and to prevent galvanic action between two different ground systems. If you're not supposed to tie the A.C. ground to the grid, where does it ground to? Is it supposed to 'float', in which case you're counting on an efficient ground at the shore power connection? Seems sketchy to me. Also, how does one get a copy of the ABYC electrical code without paying the big bucks for their seminar? If they are going to set the standards, they should be available in print to anyone who wants them and is willing to pay for the book alone. Thanks, Jeff
about the A.C. ground being tied to the boat ground grid? Seems to me that all grounds should be tied together, both for safety and to prevent galvanic action between two different ground systems. If you're not supposed to tie the A.C. ground to the grid, where does it ground to? Is it supposed to 'float', in which case you're counting on an efficient ground at the shore power connection? Seems sketchy to me. Also, how does one get a copy of the ABYC electrical code without paying the big bucks for their seminar? If they are going to set the standards, they should be available in print to anyone who wants them and is willing to pay for the book alone. Thanks, Jeff
ABYC on AC Gnd. & Nuetral
The ABYC “Standards & Recommended Practices” book is available through Bluewater Charts & Books (Ft. Lauderdale & On-line) and thru’ the ABYC @ www.abycinc.org. The AC Ground (green) is bonded directly (or thru' an optional 'recommended' Galvanic Isolator), to the boat’s main Ground Bus, per section 8.23.1.4. The AC Ground does NOT rely on upon the Shore-Power Ground connection. Neither the AC Shore-Grounded Neutral (White) nor the Ungrounded Current Carrying Conductor (Black) are grounded on the boat (8.23.1.2). Regards, Gord
The ABYC “Standards & Recommended Practices” book is available through Bluewater Charts & Books (Ft. Lauderdale & On-line) and thru’ the ABYC @ www.abycinc.org. The AC Ground (green) is bonded directly (or thru' an optional 'recommended' Galvanic Isolator), to the boat’s main Ground Bus, per section 8.23.1.4. The AC Ground does NOT rely on upon the Shore-Power Ground connection. Neither the AC Shore-Grounded Neutral (White) nor the Ungrounded Current Carrying Conductor (Black) are grounded on the boat (8.23.1.2). Regards, Gord
Jeff you are correct
Bob's statement ""make sure the AC ground is not connected to the DC negative"" is not the way ABYC wants it these days. They would rather you tie the green wire (AC Ground) is tied to the DC Ground, typically at only one point for safety reasons. Some people have claimed that there is a "potential" that this might cause more electrolysis due to the small current flow out the boat ground through the shaft. Here is a good write up on the "green wire" controversy. And here is some ABYC documents http://www.bluesea.com/abyc.htm
Bob's statement ""make sure the AC ground is not connected to the DC negative"" is not the way ABYC wants it these days. They would rather you tie the green wire (AC Ground) is tied to the DC Ground, typically at only one point for safety reasons. Some people have claimed that there is a "potential" that this might cause more electrolysis due to the small current flow out the boat ground through the shaft. Here is a good write up on the "green wire" controversy. And here is some ABYC documents http://www.bluesea.com/abyc.htm
Overwhelming response, Thank you all
To ALL: Thank you all for your help. I guess I will have lots of things to try this weekend. Since I am color blind, I will make sure the shore power is disconnected!
To ALL: Thank you all for your help. I guess I will have lots of things to try this weekend. Since I am color blind, I will make sure the shore power is disconnected!
Tom S...thanks for the great links!
I appreciate you posting those 2 links. Good info that I've been looking for! I didn't realize that compliance with ABYC standards was voluntary, I was under the impression that U.S. boatbuilders and repair shops were REQUIRED to follow their code, just like us electricians are required to follow the N.E.C. (National Electrical Code). Believe me, there is no such thing as 'voluntary compliance' as far as the N.E.C. is concerned! You either do it their way or you don't do it at all! Still, from what I read of the ABYC requirements (suggestions?), it all seems to be good engineering and it's pretty close to various sections of the NEC, ie. back-up power systems, hazardous location wiring, proper grounding methods, etc. Anyhow, thanks again for the posting! Jeff
I appreciate you posting those 2 links. Good info that I've been looking for! I didn't realize that compliance with ABYC standards was voluntary, I was under the impression that U.S. boatbuilders and repair shops were REQUIRED to follow their code, just like us electricians are required to follow the N.E.C. (National Electrical Code). Believe me, there is no such thing as 'voluntary compliance' as far as the N.E.C. is concerned! You either do it their way or you don't do it at all! Still, from what I read of the ABYC requirements (suggestions?), it all seems to be good engineering and it's pretty close to various sections of the NEC, ie. back-up power systems, hazardous location wiring, proper grounding methods, etc. Anyhow, thanks again for the posting! Jeff
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