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Grounding Probe
If you have any device leaking elektricity to the water, and you are
affraid of negative effects on your tank inhabitants, the grounding probe will make things even worse. It will INCREASE the current flowing from the failed device to the ground through the water column. Without the probe, the resistance of glass, wood is high enought to make the current flow almost zero. The probe will lower this resistance to zero and current will be limited only with the weak resistance of broken insulation of the device. If you narrowed the problem to the light fixture I would look to this really closer. Does it have metal reflector? Is it correctly grounded? Lights usualy radiate some electricity to water, but if the fixture is designed correctly it is negligible. Do one test: disconnect the probe from ground and put a multimeter in series with it on a AC current settings. If you measure less then 1mA I would not worry about. If it is more than that I would fix your lights. Let me give you an example - the original fluorescent fixture from CustomSeaLights causes readings on a level about 0.2mA. DIY fixture I made with my friend gives reading 0.8mA when one lamp is on and 1.6mA when both lamps are on. This is a reason for us to redesign reflector and replace glass mirror with grounded polished aluminium. In your case I would fix the light fixture and I would get rid of the probe for sure. In a matter of your GFCI plug - what is it rated for? 5-6mA? Or maybe bigger? 1mA current is detectable by human skin. 5mA is already very painful. GFCI plug will not react to very small currents. wrote in message ... Just wondering here...I put a ground probe in one of my tanks and hooked it up to a GFCI outlet. I was feeling some shocks when I touched the water. I narrowed the problem down to the lighting. Anyway, the GFCI never tripped. I thought aside from supposedly ridding the tank of stray voltage, that it would also trip the GFCI when the water is touched. I guess not? What's the deal? |
Grounding Probe
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Grounding Probe
Well, I thought the outlet was a GFCI since it was in my kitchen not too far
from an actual GFCI outlet. I just tested that one and it did not shut off the outlet at the tank. Guess I'll be changing that outlet today...although I think I have a portable GFCI I can attach for now. It's only a temporary setup for an injured fish. It's a 25 gallon tank with an Eclipse hood and it's that light that was causing the little shocks. Probably because some water got inside it. It's a big puffer in there and he splashes allot. So, anyway I'll just keep the light unplugged for now. I'm sure it's fine and just needs to dry out. You're answer though does lead me to another question with my big tank. I have that on a GFCI outlet (for sure) with 2 power strips plugged into that. The ground probe is plugged into one of the power strips. Will the probe still trip the GFCI before I stick my hand in or must it be plugged directly into the outlet, not the power strip. Thanks! "Brian C. Attwood" wrote in message ... wrote: Just wondering here...I put a ground probe in one of my tanks and hooked it up to a GFCI outlet. I was feeling some shocks when I touched the water. I narrowed the problem down to the lighting. Anyway, the GFCI never tripped. I thought aside from supposedly ridding the tank of stray voltage, that it would also trip the GFCI when the water is touched. I guess not? What's the deal? The GFCI will only protect you against leaking devices that are plugged into the GFCI. It does not really matter if ground probe is plugged into the GFCI or not, because the GFCI compares the current in the hot and neutral wires to detect a fault rather than monitoring the ground wire. The ground probe merely provides a means for a bad device to leak to ground and trip the GFCI before you stick your hand in. I would suggest that you make sure that ALL devices are plugged into the GFCI, otherwise you are not fully covered. If it still does not trip I would check to make sure the GFCI is wired correctly. |
Grounding Probe
Pszemol wrote:
"Brian C. Attwood" wrote in message ... It should not matter where probe is plugged in as long as it provides a path to ground. The GFCI trips when it detects that the current in the host wire is not equal to the current in the neutral wire, meaning that the difference must be going somewhere else, i.e. the ground probe or your hand. Whether that current goes through the GFCI's ground wire or another outlet (or your body) makes no difference. If your powerstrip was not adequately grounded then that would be a problem. Everything is right of course, but I need to add GFCI will normally NOT trip when the current difference, in other words: leakage to ground is less then 5-6 mA. At this value you may still feel a sting when you touch the water but the current will be too small for GFCI to trip. It just protects you from being electrocuted :-) Good point, although intuitively I would think that a voltage sufficient enough to cause a 5-6mA current through a person (so-so conductor) might result in quite a bit more current through a metal ground probe (better conductor) and thus trip the GFCI. Either way, not getting electrocuted is always preferred. |
Grounding Probe
In article , Pszemol wrote:
In your case I would fix the light fixture and I would get rid of the probe for sure. Do not get rid of the ground probe. It could save your life. All sal****er tanks should have a ground probe. |
Grounding Probe
what rating of a GFCI should I get? 5-6mA or what ,to insure my safety?
"Brian C. Attwood" wrote in message ... Pszemol wrote: "Brian C. Attwood" wrote in message ... It should not matter where probe is plugged in as long as it provides a path to ground. The GFCI trips when it detects that the current in the host wire is not equal to the current in the neutral wire, meaning that the difference must be going somewhere else, i.e. the ground probe or your hand. Whether that current goes through the GFCI's ground wire or another outlet (or your body) makes no difference. If your powerstrip was not adequately grounded then that would be a problem. Everything is right of course, but I need to add GFCI will normally NOT trip when the current difference, in other words: leakage to ground is less then 5-6 mA. At this value you may still feel a sting when you touch the water but the current will be too small for GFCI to trip. It just protects you from being electrocuted :-) Good point, although intuitively I would think that a voltage sufficient enough to cause a 5-6mA current through a person (so-so conductor) might result in quite a bit more current through a metal ground probe (better conductor) and thus trip the GFCI. Either way, not getting electrocuted is always preferred. |
Grounding Probe
now that it is mentioned marc check your GFCI.
"Marc Levenson" wrote in message ... FWIW, I was getting shocked by my 29g a few times last week. I tried unplugging one thing after another to figure out what was causing it, but never could. I have a grounding probe, btw. Jose was over, and we checked it together, and still it was very elusive. Finally, I pushed my cords firmly into the outlets, and the problem was solved. :D Marc Pszemol wrote: If you have any device leaking elektricity to the water, and you are affraid of negative effects on your tank inhabitants, the grounding probe will make things even worse. It will INCREASE the current flowing from the failed device to the ground through the water column. Without the probe, the resistance of glass, wood is high enought to make the current flow almost zero. The probe will lower this resistance to zero and current will be limited only with the weak resistance of broken insulation of the device. If you narrowed the problem to the light fixture I would look to this really closer. Does it have metal reflector? Is it correctly grounded? Lights usualy radiate some electricity to water, but if the fixture is designed correctly it is negligible. Do one test: disconnect the probe from ground and put a multimeter in series with it on a AC current settings. If you measure less then 1mA I would not worry about. If it is more than that I would fix your lights. Let me give you an example - the original fluorescent fixture from CustomSeaLights causes readings on a level about 0.2mA. DIY fixture I made with my friend gives reading 0.8mA when one lamp is on and 1.6mA when both lamps are on. This is a reason for us to redesign reflector and replace glass mirror with grounded polished aluminium. In your case I would fix the light fixture and I would get rid of the probe for sure. In a matter of your GFCI plug - what is it rated for? 5-6mA? Or maybe bigger? 1mA current is detectable by human skin. 5mA is already very painful. GFCI plug will not react to very small currents. wrote in message ... Just wondering here...I put a ground probe in one of my tanks and hooked it up to a GFCI outlet. I was feeling some shocks when I touched the water. I narrowed the problem down to the lighting. Anyway, the GFCI never tripped. I thought aside from supposedly ridding the tank of stray voltage, that it would also trip the GFCI when the water is touched. I guess not? What's the deal? -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com |
Grounding Probe
My GCFI is the breaker itself. When it trips, the room goes dead.
Marc J wrote: now that it is mentioned marc check your GFCI. -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com |
Grounding Probe
They aren't. I have two circuits in my room. Each is a 20amp breaker, but one
is GCFI. My lighting is on the GCFI, as well as my heaters. The return pumps are on the regular outlets. I've had the electrician out here two times to get it set up the way I like it. Marc J wrote: Marc all your eggs in one basket is a very not smart idea. Home depot has three for $20 outlet style I'm sure you could install them or I can if you feel uncomfortable. " -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com |
Grounding Probe
pumps need the/a GFCI too. Didn't you have a pump failure recently? just a
thought. feel free to tell me shut up if I'm pestering you..lol "Marc Levenson" wrote in message ... They aren't. I have two circuits in my room. Each is a 20amp breaker, but one is GCFI. My lighting is on the GCFI, as well as my heaters. The return pumps are on the regular outlets. I've had the electrician out here two times to get it set up the way I like it. Marc J wrote: Marc all your eggs in one basket is a very not smart idea. Home depot has three for $20 outlet style I'm sure you could install them or I can if you feel uncomfortable. " -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com |
Grounding Probe
That pump was bad since day one. The replacement works great.
Marc J wrote: pumps need the/a GFCI too. Didn't you have a pump failure recently? just a thought. feel free to tell me shut up if I'm pestering you..lol "Marc Levenson" wrote in message ... They aren't. I have two circuits in my room. Each is a 20amp breaker, but one is GCFI. My lighting is on the GCFI, as well as my heaters. The return pumps are on the regular outlets. I've had the electrician out here two times to get it set up the way I like it. Marc J wrote: Marc all your eggs in one basket is a very not smart idea. Home depot has three for $20 outlet style I'm sure you could install them or I can if you feel uncomfortable. " -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com |
Grounding Probe
"SG" wrote in message ...
In article , Pszemol wrote: In your case I would fix the light fixture and I would get rid of the probe for sure. Do not get rid of the ground probe. It could save your life. All sal****er tanks should have a ground probe. GFCI saves life... Grounding probe is designed just to keep your fish from getting sick from stray voltages - but I guess it is only a marketing thing rather than a real deal... because the real thing is that grounding probe is making things worse for your fish. It creates stray currents which are far worse than stray voltages for a living things. But this is only IMHO. I would be happy to hear from you about grounding probe saving lives... please explain how does it do it? |
Grounding Probe
"mark" wrote in message . ca...
what rating of a GFCI should I get? 5-6mA or what ,to insure my safety? Standard, 5-6mA, protects you from geting killed. It will not protect you from just getting shocked. You can feel the current on the level of 1mA. 5mA is already very painful and you GFCI could pass this kind of current without tripping off. If you can get lower rated GFCI - do not buy it... It could trip without a good reason and it could be anoying like hell. And one more thing as a warning - one time I purchased a pluged GFCI and it tripped every time a power outage happened. It did not matter it lasted 1 minute or 1 hour. Power went down, GFCI plug disconnected the circuit :-( My tank powered by this GFCI was shut off for the whole night just because power went down for a minute at 10pm and I did not go to the tank to check things up... Next morning my shrimp was laying bottom up on the sand. It slowly recovered when I turned pumps on and it was a miracle for me... but the GFCI plug went to the garbagge. |
Grounding Probe
it saves the lives of my blue spot stingray:)
i went through a un commented number of them after I got my first, the tank is outside, and they would not do well, I bought that tank used, with the ray, it took only a few days to kill it, and the next ...... there was very very little stray voltage leaking from something but it was bothering him, now the probe, and cooler temps and ive been keeping the same one for a while ill have to dig out dates but I think its over a year now. So you are saying, that grounding water column and leading much stronger electric current out of this failured device to ground, through the water and the stingray was better than leaving voltage not grounded? It does not make sense - try to imagine birds sitting on a 20kV wire hanging between hig-voltage poles. Do they feel stray voltage around them in the air? On their legs? NOT! They would certainly feel it when somebody would aproach them with a something like a "grounding probe". Their would become a nice, birdy fireworks :-) The same works with water, stray voltage in the water, and leading these voltages to ground with a grounding probe. Basicaly, the interest of normally grounded human (shoes?) putting his hand into the water and acting as a poor grounding probe conflicts with the interest of fish inside the tank. Fish do not want any grounding probe in their tank, like birds sitting on 20kV wire do not want any grounding probes near them. I would suspect that a grounding probe **WITH** a GFCI would do a good job at sending that stray current away from the guy with his hand in his tank, between the time that the shock occurs and the GFCI trips, but read into that third word suspect in this statement as I have no proof either way. just seems the probe is a much less resistant path then a guy with his arm in a tank As I said - there are two different aspects of this issue and both need to be discussed separatelly. In my opinion, I am sufficiently protected against being electocuted by the GFCI plug and I do not need additional grounding probe. In this case I would not install one to not put miliamps not tripping GFCI going through the bodies of my fish inside the tank. Yes, I will risk being stung by the small voltage not tripping GFCI normally, showing itself as a stray voltage, but I would take this risk just to not make any currents flow in the water column. Bottom line: GFCI - big YES, Grounding Probe - big NO! |
Grounding Probe
"richard reynolds" wrote in message . ..
first off rays and sharks sense electrical differences and use that to hunt so YES he noticed that he was on a 20kv wire even if a bird wont notice it. there are biological receptors(?) (shark experts jump in and tell me what its called) that sences very very low pockets(?) of electricity using that to find prey, and hide from prediators OK - I would ask the next question - do they sense voltage difference or maybe electric currents flowing? Assuming the very low impedance of the salt water pointed here several times, it should be rather currents because it will be most likely no significant voltage potentials in the seawater. I am not a shark/ray expert myself - we should ask some marine biologist :-) second you assume its a device, you make an assumption that honestly I do make myself, BUT at the same time cant find your also assuming this stray voltage occurs FROM the tank and goes into the sump where one of the probs are also something I cant prove either way, this is a preditor tank, there are 2 NO flor lights above a glass plate and as its outside that light fixture has been sealed its 100% submersiable and even without the lights its an issue, thats the only AC in or around the tank, everything else is in the sump. IF it were a failing device in the sump and IF it grounded to the probe so it would shock the water in the sump not an issue. there are no closed loops/powerheads or anything else in the tank all the electrical is in the sump 1. Fluorescent lights can be very big, sometimes the biggest source, of electricity in the water. It is the biggest source in case of my DIY fixture with no metal reflectors (I used glass mirrors). Even if the lamp connectors are sealed the tube itself radiates electromagnetic waves through the glas. Make a test, and touch a glass part of tube with a burned starter - it will glow. It glows from current flowing from the connectors, through the glass, your hands to the ground. The same is when the water is grounded. 2. Assuming all other devices are in the sump, together with the probe there is no risk that your probe will electrocute your fish when your powerhead will loose the insulation and starts leaking electricity to water. It will be shorted to the probe and GFCI will trip - no problem. Unfortunately it will not cure the problem with fluorescent fixture or any other elec. device submersed in the tank itself instead of the sump. I say it cant be seperate it HAS to be kept together its always a risk to livestock vs risk to ourselves. both need to be eliminated I agree that sharks owners have bigger problems if their fish are feeling stray voltages... But sharks in home aquariums are a big mistake anyway... so there is another story right here :-)) Bottom line: GFCI - big YES, Grounding Probe - big NO! again disagreeing he) I challenge you to prove your point of view based on the science :-) I would be glad proven wrong - I am always happy to learn something new ;-) |
Grounding Probe
GFCI's are installed in bathrooms and kitchens because you are literally
surrounded by potential grounds. The plumbing system! Running Water! Metal Basins! etc... You can hold an AC hot wire and not get shocked if you are not grounded.... Not the name is GROUND FAULT CIRCUIT INTERRUPTER... You have to have a ground fault to trip the circuit interrupter.... -- Stephen -------------------------------------------------- In-Dash MP3 http://www.highwaymp3.com/ -------------------------------------------------- "Pszemol" wrote in message ... "J" wrote in message news:TeGVa.15711$YN5.13321@sccrnsc01... Without a grounding probe how will the leaking voltage trip the GFCI. It WONT, Yes, it would, using your body grounded to the floor as a conductor. How is a GFCI working in your bathroom without "grounding probe"? :-) How is a GFCI on your hair-dryer working without a probe? :-) YOU WILL BE THAT PATH for the potential/voltage in the tank. Exactly. This is the reason GFCI will trip on a safe level of current. No GFCI manufacturer is selling their device as protecting against electrick shock. They sell these to prevent you being KILLED by the electric current. You can still feel a sting. I myself would rather a GFCI trip once in a while rather than electrocute myself but to each his own. Right. And since I know in an event of a device leaking I would NOT be electrocuted because GFCI will tripp BEFORE the current rises to a dangerous levels, I do not see the reason to use probe. I'm in my third semster in Electronics and have a certificate in Electrical as well as H.V.A.C. and have worked in Commercial building automation so you decide who to believe. GFCI's NEED GROUNDING to work properly it says so on the box. :-))) Oh well... Good luck in your study :-) I think I made my point but I do not expect to convince everyone. |
Grounding Probe
"Stephen" wrote in message ...
GFCI's are installed in bathrooms and kitchens because you are literally surrounded by potential grounds. The plumbing system! Running Water! Metal Basins! etc... The same situation could happen in any other wet environment. Such as fish tank: salt water spilled on the floor wehre you stand combined with a faulty electric device submersed in the water where you put your hands can be very deadly combination and that is the reason smart people recommend GFCI for us to power fish tanks equipment from. You can hold an AC hot wire and not get shocked if you are not grounded.... Right. Is there anybody claiming anything else here? See my "birds sitting on a 20kV wire" example... :-) Not the name is GROUND FAULT CIRCUIT INTERRUPTER... You have to have a ground fault to trip the circuit interrupter.... I hope you do not derive all your knowledge about GFCI from its name ;-) I can easily imagine a scenario when GFCI will trip when grounding will be perfect and DO NOT trip when grounding is faulty... If your imagination does not work for some reason I can give you full description of such scenarios. Is then the GFCI name wrong? Let's change it! ;-) |
Grounding Probe
He's a troll I believe. The answers to all his statements and questions are
in my post but he won't listen or understand. "Stephen" wrote in message ... GFCI's are installed in bathrooms and kitchens because you are literally surrounded by potential grounds. The plumbing system! Running Water! Metal Basins! etc... You can hold an AC hot wire and not get shocked if you are not grounded.... Not the name is GROUND FAULT CIRCUIT INTERRUPTER... You have to have a ground fault to trip the circuit interrupter.... -- Stephen -------------------------------------------------- In-Dash MP3 http://www.highwaymp3.com/ -------------------------------------------------- "Pszemol" wrote in message ... "J" wrote in message news:TeGVa.15711$YN5.13321@sccrnsc01... Without a grounding probe how will the leaking voltage trip the GFCI. It WONT, Yes, it would, using your body grounded to the floor as a conductor. How is a GFCI working in your bathroom without "grounding probe"? :-) How is a GFCI on your hair-dryer working without a probe? :-) YOU WILL BE THAT PATH for the potential/voltage in the tank. Exactly. This is the reason GFCI will trip on a safe level of current. No GFCI manufacturer is selling their device as protecting against electrick shock. They sell these to prevent you being KILLED by the electric current. You can still feel a sting. I myself would rather a GFCI trip once in a while rather than electrocute myself but to each his own. Right. And since I know in an event of a device leaking I would NOT be electrocuted because GFCI will tripp BEFORE the current rises to a dangerous levels, I do not see the reason to use probe. I'm in my third semster in Electronics and have a certificate in Electrical as well as H.V.A.C. and have worked in Commercial building automation so you decide who to believe. GFCI's NEED GROUNDING to work properly it says so on the box. :-))) Oh well... Good luck in your study :-) I think I made my point but I do not expect to convince everyone. |
Grounding Probe
My goal is not to force you to change your mind.
My goal was to express my opinion on this subject. It is up to each of us to make the best decision in order to care for animals we take our responsibility for. I know ! :) As much as the 'theory' about stray voltages is appealing, and might explain some strange or weird behaviors of our fish, including causes for HLLE in some fish, no evidence has been shown to support such allegations. there is some evidence but as i hinted to the study basically says we need to study it which isnt enough. Please, describe your setup in more details. What do you use for water circulation? What devices are submersed in the water column? Where is the probe placed in the water? being a preditor tank the ONLY circulation is from the sump to tank (and back duh:) ) the sump is a 20long the tank is a 75 and completely covered in diatom algae :( the only thing in the tank is the ray, a porcupine puffer, a 4" very fine sand bed (forget dsb the ray tosses it over and over) and a ground probe (not the only one, not always in there) as its outside and as outside is easy to get to dirt to ground it instead of using the ground wire from the main i ran a seperate wire 10gague solid copper to a 10' grounding rod burried about 9' deep its all of 4' from the sump to the rod the box from the main has a circuit breaker plus one of them hard cutoff switches the breaker is a gfci breaker, this is attached to both ground probes and the canister heater one ground probe is in the sump the other is in the tank. the heaters grounded but I THINK that its only the outside thats really grounded not the part that touches the water when its working, ive tested this a few times and to the best i could come up with this is the case. I have 2 skimmers both americal typhoon's ran with rio 3500's with the rio rtv adapter YES IVE CHECKED THEM THERE NOT THE CAUSE figured id get that straight out because w/o it ppl are gona jump on these poor rios :) the return pump which ive checked out over and over is a slightly older little giant 3-md something there is a canister heater which probibly hasnt even flickerd sence april and a fan on a thermostat its ran on sence april :) tank temp is kept around 72~74tops i get the same very very small stray voltage going through the probe What do you mean "voltage going through the probe"? I have already explained here a mistake people do measuring the voltage. You can prove me wrong by using very different voltmetter and measuring the voltage again. Tell me please what you have read from both readings. ill have to dig up details ive posted them before and while ive done it a few times, id like to not mess up the details. ive used analog and digital meters in several AC and DC modes, all good meters. for all I can tell there is NOTHING in the tank adding to any current besides the tank/water/fish Tell me more how did you find out about this. trial and error and a few dead rays :( I should point out the "for all I can tell" part one more time. though I havent taken any scientificly acurate method of chasing down whatever is the cause, maybee i will probibly wont, i like the guy but what i have is working:) I am glad you are happy. But you can help others adding more details about your setup. Please do. ill be glad to do any tests you can think of in the interest in providing a better place :), but I'd like to not re do them all, the last time I went through all of these I lost a ray, there $80 a pop Id rather not kiss this one bye bye along with the $80 to get a replacement (side note good ad for live aquaria every time ive had to replace them they have been real good about getting one that fit my wishes) I am not an electronics expert, but ive been around the block many times. all the major electrical work like the grounding rod and the run from the mains was done by a licensed electrcian as rqd by local code :) I even went as far as having it all inspected by a different guy just to make sure it wasnt something fsked up with the first guys wiring -- richard reynolds |
Grounding Probe
The same situation could happen in any other wet environment.
Such as fish tank: salt water spilled on the floor where you stand combined with a faulty electric device submersed in the water where you put your hands can be very deadly combination and that is the reason smart people recommend GFCI for us to power fish tanks equipment from. Right, Especially on concrete! (Giant solid gelatin).... But what about wood flooring or Carpet? The majority of aquarium devices do not include grounds in their cords. However they really should. A ground probe provides a positive ground to the tank to trip the GFCI immediately in case of a problem. It is just an added safety measure. However, like you I believe the other stuff is hocus pocus snake oil..... However, after saying that, imagine the fact that the entire tank essentially becomes a Faraday Cage once the ground it inserted. More physics than I would like to think about this early. I am sure that a book could be written about this subject if studied in a lab. Only then would such discussions be resolved. Until then this is just opinion versus opinion.... "Pszemol" wrote in message ... "Stephen" wrote in message ... GFCI's are installed in bathrooms and kitchens because you are literally surrounded by potential grounds. The plumbing system! Running Water! Metal Basins! etc... The same situation could happen in any other wet environment. Such as fish tank: salt water spilled on the floor wehre you stand combined with a faulty electric device submersed in the water where you put your hands can be very deadly combination and that is the reason smart people recommend GFCI for us to power fish tanks equipment from. You can hold an AC hot wire and not get shocked if you are not grounded.... Right. Is there anybody claiming anything else here? See my "birds sitting on a 20kV wire" example... :-) Not the name is GROUND FAULT CIRCUIT INTERRUPTER... You have to have a ground fault to trip the circuit interrupter.... I hope you do not derive all your knowledge about GFCI from its name ;-) I can easily imagine a scenario when GFCI will trip when grounding will be perfect and DO NOT trip when grounding is faulty... If your imagination does not work for some reason I can give you full description of such scenarios. Is then the GFCI name wrong? Let's change it! ;-) |
Grounding Probe
"J" wrote in message news:guIVa.16583$YN5.16888@sccrnsc01...
He's a troll I believe. Are you sure you want to start childish name calling game? The answers to all his statements and questions are in my post but he won't listen or understand. In which of your posts are all the answers? |
Grounding Probe ( something to read guys)
"Boomer" wrote in message ...
http://www.aquarium.net/1298/1298_3.shtml I read this before and I strongly disagree. Let me quote something terrible: "So if you now accept this as the normal case for SW tanks, you begin asking yourself if this is a problem. I have discussed this with several educated folks, and we have concluded that the minute currents in the tank, due to grounding with titanium probes, are much less significant than unterminated voltages on the order of tens or hundreds of volts" - this is totaly FALSE. And I have explained this already based on an example with standing on 10th floor and on the 2nd floor. Standing on the 10th floor (unterminated voltage) is not dangerous until you fall down (create a current flow). And by adding grounding probe to those detected stray voltages you are creating "minute currents" on the levels about 0.1-1mA even if all devices are in good order. I do not know Gerry Parker, but I can only say it is not enough to have an access to labolatory grade test equipment - you also have to know what are you exactly measuring. The test equipment unfortunately will not do the thinking part for you... http://avdil.gtri.gatech.edu/RCM/RCM...ingProbes.html This one, in oposite, is very good and convincing. "In conclusion, the addition of a "grounding probes" will guarantee an electrical current flow in your aquarium and may induce erratic behavior or disease in your fish. If you have defective aquarium appliances that are creating a current path in your aquarium by using the salt water as a conductive medium, then the solution is to repair the appliances or replace them... not divert a portion of the current into a "grounding probe"." This is exactly what I am trying to say here. "NO" to grounding probes - period. |
Grounding Probe
"Stephen" wrote in message ...
Right, Especially on concrete! (Giant solid gelatin).... But what about wood flooring or Carpet? The majority of aquarium devices do not include grounds in their cords. However they really should. A ground probe provides a positive ground to the tank to trip the GFCI immediately in case of a problem. It is just an added safety measure. However, like you I believe the other stuff is hocus pocus snake oil..... This "added safety measure" is not needed. That is my point exactly. If there is no current flow enough to trip GFCI there is also not enough current flow to electrocute you. Do you agree on this matter? And, when you add grounding probe you are CAUSING current flows from a faulty device to the ground through the water column. GFCI are not designed to trip on current levels which stress your fish, so such currents can flow to the grounding probe unstopped. That is the reason I am strongly against the grounding probe as a cure to the faulty device leaking some electricity to the water. In the value range from 0-5mA GFCI will not react, so such currents as 5mA could flow from the faulty device to the ground with a help of this probe. However, after saying that, imagine the fact that the entire tank essentially becomes a Faraday Cage once the ground it inserted. I disagree. This is not a very good analogy. Situation in the fish tank is far more complicated. I would say that fish body resistance to the AC current is comparable to the salt water resistance so you cannot neglect currents flowing through the fish body in the calculation. The body of any living thing is full of electrolytes conducting electricity very well. More physics than I would like to think about this early. I am sure that a book could be written about this subject if studied in a lab. Only then would such discussions be resolved. Until then this is just opinion versus opinion.... I see you are not willing to challenge my scenarios with GFCI, ok :-) |
Grounding Probe
feel free to tell me shut up if I'm pestering you..lol
Shut up! Heehe... Helping Marc to say it. He is just too nice to use those words. CapFusion,... |
Grounding Probe ( something to read guys)
In article , Pszemol wrote:
"Boomer" wrote in message ... http://www.aquarium.net/1298/1298_3.shtml I read this before and I strongly disagree. Disagree all you want, but the paper is correct. The findings were based on scientific procedures and principles. http://avdil.gtri.gatech.edu/RCM/RCM...ingProbes.html This one, in oposite, is very good and convincing. It is convincing, but incorrect. The author did not do any research to arrive at their conclusions. If you have defective aquarium appliances that are creating a current path in your aquarium by using the salt water as a conductive medium, then the solution is to repair the appliances or replace them... not divert a portion of the current into a "grounding probe"." The grounding probe will cause the GFCI or circuit breaker to trip alerting you to the possibility of defective equipment. There will be currents flowing in an aquarium with or without the grounding probe. This is the nature of AC. |
Grounding Probe
"Pszemol" wrote in message ... "Stephen" wrote in message ... Right, Especially on concrete! (Giant solid gelatin).... But what about wood flooring or Carpet? The majority of aquarium devices do not include grounds in their cords. However they really should. A ground probe provides a positive ground to the tank to trip the GFCI immediately in case of a problem. It is just an added safety measure. However, like you I believe the other stuff is hocus pocus snake oil..... This "added safety measure" is not needed. That is my point exactly. If there is no current flow enough to trip GFCI there is also not enough current flow to electrocute you. Do you agree on this matter? I think you are confusing the functionality of a GFCI to a circuit breaker.... GFCI detects current leaking to ground, not the neutral wire... Without a ground, thats all there would be, current leaking to neutral.... And, when you add grounding probe you are CAUSING current flows from a faulty device to the ground through the water column. GFCI are not designed to trip on current levels which stress your fish, so such currents can flow to the grounding probe unstopped. That is the reason I am strongly against the grounding probe as a cure to the faulty device leaking some electricity to the water. In the value range from 0-5mA GFCI will not react, so such currents as 5mA could flow from the faulty device to the ground with a help of this probe. However, after saying that, imagine the fact that the entire tank essentially becomes a Faraday Cage once the ground it inserted. I disagree. This is not a very good analogy. Situation in the fish tank is far more complicated. I would say that fish body resistance to the AC current is comparable to the salt water resistance so you cannot neglect currents flowing through the fish body in the calculation. The body of any living thing is full of electrolytes conducting electricity very well. More physics than I would like to think about this early. I am sure that a book could be written about this subject if studied in a lab. Only then would such discussions be resolved. Until then this is just opinion versus opinion.... I see you are not willing to challenge my scenarios with GFCI, ok :-) |
Grounding Probe
"Stephen" wrote in message ...
I think you are confusing the functionality of a GFCI to a circuit breaker.... GFCI detects current leaking to ground, not the neutral wire... Without a ground, thats all there would be, current leaking to neutral.... No, I am not confusing it. I fully understand how it works. And you are *almost* right saying it detects the current leaking to the ground wire. The exact statement is that GFCI detects a *difference* in the current value between hot and neutral wire. This difference can leak to the ground wire by the grounding probe *OR* through your hands, legs, the floor (or water pipes or gas line) then dirrectly to the ground. |
Grounding Probe
"SG" wrote in message ...
In article , Pszemol wrote: This "added safety measure" is not needed. That is my point exactly. If there is no current flow enough to trip GFCI there is also not enough current flow to electrocute you. Do you agree on this matter? A GFCI will not trip unless a ground is present. Once a ground is present a GFCI takes some time to trip (but it is very fast). I want to be a ground for 120v for exactly zero seconds and no more. It is your choice :-) |
Grounding Probe
"richard reynolds" wrote in message .. .
My goal is not to force you to change your mind. My goal was to express my opinion on this subject. It is up to each of us to make the best decision in order to care for animals we take our responsibility for. I know ! :) Good :-) there is some evidence but as i hinted to the study basically says we need to study it which isnt enough. Exactly :-) being a preditor tank the ONLY circulation is from the sump to tank (and back duh:) ) the sump is a 20long the tank is a 75 and completely covered in diatom algae :( the only thing in the tank is the ray, a porcupine puffer, a 4" very fine sand bed (forget dsb the ray tosses it over and over) and a ground probe (not the only one, not always in there) Is it glass tank? as its outside and as outside is easy to get to dirt to ground it instead of using the ground wire from the main i ran a seperate wire 10gague solid copper to a 10' grounding rod burried about 9' deep its all of 4' from the sump to the rod the box from the main has a circuit breaker plus one of them hard cutoff switches the breaker is a gfci breaker, this is attached to both ground probes and the canister heater one ground probe is in the sump the other is in the tank. the heaters grounded but I THINK that its only the outside thats really grounded not the part that touches the water when its working, ive tested this a few times and to the best i could come up with this is the case. I have 2 skimmers both americal typhoon's ran with rio 3500's with the rio rtv adapter YES IVE CHECKED THEM THERE NOT THE CAUSE figured id get that straight out because w/o it ppl are gona jump on these poor rios :) the return pump which ive checked out over and over is a slightly older little giant 3-md something there is a canister heater which probibly hasnt even flickerd sence april and a fan on a thermostat its ran on sence april :) The only way to eliminate this heater from the picture is completely remove it from the AC outlet. Assumtion it does not flicker because water is hotter than the thermostate setup is probably true, but it does not say if we have current leak from it to water or not... It could leak even if the thermostate does not turn it on. It could be one pole switch, so one pole can be constantly on. i get the same very very small stray voltage going through the probe What do you mean "voltage going through the probe"? I have already explained here a mistake people do measuring the voltage. You can prove me wrong by using very different voltmetter and measuring the voltage again. Tell me please what you have read from both readings. ill have to dig up details ive posted them before and while ive done it a few times, id like to not mess up the details. ive used analog and digital meters in several AC and DC modes, all good meters. I would be very surprised if you measured the same stray voltages with different types of meters :-) Their readins will mostly depend on their internal resistance compared to the resistance of the devices insulation. for all I can tell there is NOTHING in the tank adding to any current besides the tank/water/fish Tell me more how did you find out about this. trial and error and a few dead rays :( I should point out the "for all I can tell" part one more time. Right... and since I am not a ray expert I have no idea what was stressing your fish. In terms of electicity in other hand, I know what I am saying... :-) I am glad you are happy. But you can help others adding more details about your setup. Please do. ill be glad to do any tests you can think of in the interest in providing a better place :), but I'd like to not re do them all, No, if everything is working - do not change anything... :-) I would be only interested in two things: - what is the influence of you heater being off to the stray voltages - what is the reading of stray voltages from a set of different meters :-) I am not an electronics expert, but ive been around the block many times. all the major electrical work like the grounding rod and the run from the mains was done by a licensed electrcian as rqd by local code :) I even went as far as having it all inspected by a different guy just to make sure it wasnt something fsked up with the first guys wiring Good. I have no doubt your grounding is good. BTW - do you have pictures of your outside tank setup? I am interested in seeing it if you have them available. |
Grounding Probe
Is it glass tank?
yes The only way to eliminate this heater from the picture is completely remove it from the AC outlet. Assumtion it does not flicker because water is hotter than the thermostate setup is probably true, but it does not say if we have current leak from it to water or not... It could leak even if the thermostate does not turn it on. It could be one pole switch, so one pole can be constantly on. sorry didnt give enough details, the heater isnt leaking ive checked it a number of times, both removal from E supply and total removal from tank, my reference to flickering is the tank temp must be slightly colder than a normal reef, and its outside in SoCal it rained today and the low is probibly 80F, i was just providing as much detail as i could and missed a step. I would be very surprised if you measured the same stray voltages with different types of meters :-) Their readins will mostly depend on their internal resistance compared to the resistance of the devices insulation. i used at least 4, 1 is analog and a tad old late '80s, 2 of which are crappy digitals well $$$ kinda crappy but not analog or $2500 digitals either, the tectronics is a good ociliscope with a V probe and one of them tectronics isolators(forgot what its called) plug probe into it so you dont screw up scope when messing with things Right... and since I am not a ray expert I have no idea what was stressing your fish. In terms of electicity in other hand, I know what I am saying... :-) I just like the blue spot he is cool (actually think its a she but not 100% sure) No, if everything is working - do not change anything... :-) I would be only interested in two things: - what is the influence of you heater being off to the stray voltages - what is the reading of stray voltages from a set of different meters :-) ive done it w/o the heater when I was trying to isolate the issue, as for the readings ill either have to re take them or search around for the last time i posted them. Good. I have no doubt your grounding is good. BTW - do you have pictures of your outside tank setup? I am interested in seeing it if you have them available. i can make them available, but i was serious its covered in algae :( -- richard reynolds |
Grounding Probe
Pszemol wrote: Yes, it would, using your body grounded to the floor as a conductor. How is a GFCI working in your bathroom without "grounding probe"? :-) How is a GFCI on your hair-dryer working without a probe? :-) Actually, the GCFI (I believe that is the correct order of initials) is grounded when it is wired into the wall. And I believe I read that 10mA trips it. Marc -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com |
Grounding Probe
Marc Levenson wrote in message ...
Yes, it would, using your body grounded to the floor as a conductor. How is a GFCI working in your bathroom without "grounding probe"? :-) How is a GFCI on your hair-dryer working without a probe? :-) Actually, the GCFI (I believe that is the correct order of initials) both gfci and gcfi are pointing to the same gfi or electronics device that seperates the supply from the devices when a ground fault is found. ANSI calls it a GFCI so if one were to argue there one of the ones setting the standards so they are correct :| ive seen both used though, so is a mandarin goby correct really it is because its the 'common name' not meaining much when it comes to its scientific name which neither has mandarin or goby in it. same aplies here is grounded when it is wired into the wall. your missing a step but thats ok the devices ground means little (not nothing) it really has little to do with "ground" as a third wire, in easy terms it compars what is going to a device from what is coming back, if there different it trips in electronics if there is a difference then some current is going to ground and its called a ground fault, it wont trip if there is a short, because the current going out the supply and coming back on the return will be the same, even if its too much current it doesnt know the difference. And I believe I read that 10mA trips it. you can buy these in more and less sensitive models depending on there use. Marc -- Personal Page: http://www.sparklingfloorservice.com/oanda/index.html Business Page: http://www.sparklingfloorservice.com Marine Hobbyist: http://www.melevsreef.com -- richard reynolds |
Grounding Probe ( something to read guys)
"Boomer" wrote in message ...
No Marc and after more than 10 years even the electrical wizards (which I am not) are still arguing. I don't think anyone has a real answer as it really hasn't been tested as far as I'm concerned, I just hear statements and no data. Fact of the matter is, that even with GFIC's there is still "Induced Voltage" in the water in aquariums and I don't mean "stray voltage" witch is another issue. Any electrical device in or even near an aquarium will induce voltage into the water, it has been measured 100's of times. Power cords, cables, heaters, etc., all generate an electrical field in water, which can be measured. An Amp Clamp is an electrical device electricians use to measure amps, you don't connect anything to it, the wire in question is just placed in the "C' like ring and the number of amp's is directly proportional to the induced field the cord generates. You also don't need to plug in a fluorescent light bulb in either, if you are close enough to a high tension power line, the generated fields by themselves will light the bulb. Right. But there is no way to shield every electric device or wires in the walls to get rid of this electric noise in our modern society... You would have to get rid of TV-sets, computers, electric pumps&motors, lights definetely and you will still not recreate conditions similar to what is in the ocean, couple of miles from the shore, couple hundred meters deep :-) Also, we have to remember about the dualism of the electric energy becoming magnetic energy and vice versa... Every single change in an electric field will cause a change in magnetic field so the water as a conductor, grounded or not, will never be quiet in electro-magnetic terms as long as there is a source of electromagnetic noise near by. There is no ways to recreate ocean in 100% and grounding probe does not really help here much. BTW - Amp Clamp is working simply as transformer or Hal sensor. In the first case it just measure current flowing in the wire, not induced voltage... All public aquariums with shark tanks have the water grounded, with a probe, to eliminate any stray or induced voltage, as Elasmobranches have what is called a Lorenzini Organ, which can detect, in seawater, 0.005 uV or 5nV / cm @ 0.33 meters. I just wonder what kind of current has to flow in the seawater to generate such voltage difference... You will never find a piece of the ocean that generates say 18 V induced, but a power head may/will. If it is not in the ocean it should not be in a tank. I am not questioning the stray voltage issue, just the induced voltage issue, they are not the same. All of which means, IMHO, that a GFIC w/ probe or a GFIC / without a probe doesn't solve the two problems. Maybe someone can invent, just for us, a GFIC which also eliminates any Induced Voltage, without the potential side effect of a GFIC with a probe The voltage is always measured between two points. So when you are talking about powerhead induced voltage, lets say 18V, are refering to what two points? To the ground? Or two points in different places inside tank? In the first case - fish does not care about voltages relative to the ground unless it does have contact with this ground. Similarly like birds on 20kV wire. Pszemol It is rather odd that you disagree with Gerry Parker but agree with Robert Michelson, when Michelson states "A reference on the web for empirical data on aquarium voltage and current is" http://www.aquarium.net/1298/1298_3.shtml , which is Gerry's article. Garry did not make mistake in using scope and collecting data from it. He has measured different things correctly... He made a big mistake interpreting collected data - thats all :-) When you wear a wool sweter there are thousands volts generated and you can often feel a spark. Should I be affraid touching wool sweter in the same way I should be affraid touching 20kV coming out from the electric plant? :-) It looks to me the science behind voltages, amperes, ohms is kind of fuzzy for Garry and his "educated folks". But it is only my observation. You do not have to agree with me, of course :-) I think Gerry pretty much know his P & Q 's and knows how and what he is measuring I do not know Garry, so I cannot tell you who is he, but obviously he must be also scared like hell when he is elevated at the Observation Deck in any tower like Hancock, Sears in Chicago. I am affraid to jump, but I am fine with standing there :-)) |
Grounding Probe
"Boomer" wrote in message ...
http://www-training.llnl.gov/trainin...GFCIworks.html http://www.howstuffworks.com/question117.htm Good idea of posting such info - it will help folks not familiar very much with electricity understand this discussion better... Also, I can verify I was understanding correctly how it works, so people jumping so quickly to correct me, or call a troll, have a chance now to correct themselves :-) |
Grounding Probe ( something to read guys)
|
Grounding Probe ( something to read guys)
Thank you boomer for finally setting people on the right road.
Some here say a GFCI doesn't need a ground. I'm like thats how it works it needs the ground. ohh well have fun arguing with people here. "Boomer" wrote in message ... Pszemol Just for you, this should make you happy :-) "Ok. I finally did it. I finally figured out the whole mystery of stray voltages in a tank. I'll explain it, but first a disclaimer: All tanks should have a ground probe and a GFI socket. Parts of this document talk about doing unorthodox things to outlets and ground probes-- which fall under the category of "Kids, don't do this at home". Other parts talk imply that ground probes are not all that good, while is arguably true for your fish, it is not true for YOU. Don't risk death. Use a ground probe and GFI socket. Your tank is not worth your life. We now return to our regularly scheduled program... It happens all the time. Someone takes a multimeter and measures the voltage between their water and earth ground. They get 30 to 60 volts and then panic, thinking that this is somehow bad and that they should do something to get rid of it. They then post a question on the net and they get dozens of answers saying the same thing, "The stray voltage is caused by electrical induction with your pumps. Use a ground probe to get rid of it". Sometimes, this stray voltage is fingered as the cause to fish stress, Head and Lateral Line Erosion (HLLE), and other mysterious fish deaths. I'll cut to the chase here and say that both of these are incorrect. Induction is not the cause of stray voltages. Ground probes are not going to remove it. And it cannot possibly be the cause of fish deaths. I can't imagine how these myths got started, especially since it is very easy for someone to find the true cause of stray voltages. The true source of the stray voltages is capacitive coupling, not inductive coupling and not resistive. Ground probes (or a multimeter) actually complete the circuit for electricity to flow. Since electricity doesn't flow unless the circuit is completed, electricity won't be flowing in a tank without a ground probe. Therefore, mysterious fish deaths in tanks without a ground probe cannot be attributed to stray voltages since current is not flowing in the tank to begin with. I'm about to go into a long, technical explanation for the cause of stray voltages. If you don't want to read it, you can stop here. I've said/typed all the important practical information already. I realize that what I'm saying goes against decades of common misbelief so some proof is required. What follows is the proof. For the proof, I assume that you know basic electricity. Ohms law, resistor dividers, and the general properties of transformers, capacitors, and inductors. You don't need a great deal of this knowledge, but enough so that you can picture what's going on since there are no pictures in this post. To find the source of this stray voltage, we must eliminate sources that don't fit the evidence. Possible sources are induction, resistive coupling, and capacitive coupling. There are other possible sources, but the odds of these being the cause are so remote that we can ignore them. Here is the evidence that can be easily measured: o The "stray voltage" changes (and is repeatable) depending on what is turned on-- including the lights. o If you put a resistor between the ground probe and earth ground, and measure the current through the resistor, you will measure up to about 40 uA. The voltage across the resistor will depend on the value of the resistor, according to ohms law. o The stray voltage/current does not change with the position of the ground probe. o The voltage measured between two ground probes is zero, regardless of their position or orientation. o If you disconnect the NEUTRAL line to the pumps/lights/etc. while leaving HOT connected, the stray voltage almost DOUBLES! o The resistance, as measured by my multimeter, between the ground probe and neutral/hot of the pumps/lights/etc. is infinite (I.E., open). Let's start with induction, since that is the common myth. If this were happening, then electrically the tank would look like a transformer. The wiring in the pumps/heaters/lights would work like the primary coil of the transformer. The water itself would be the secondary coil. Unfortunately, the evidence does not support the induction theory. In a transformer, if current is not flowing in the primary then no current will flow in the secondary. If induction were the cause then disconnecting HOT would cause the stray voltage to go to zero, not double. If induction were the cause, then almost zero current would flow through the ground probe but we have 40 uA. If induction were the cause, then moving the ground probe around the tank, or using two ground probes, would give us different results. Conclusion: It's not induction! So that leaves resistive coupling, or capacitive coupling. Electrically, resistive coupling would look like a voltage divider. One resistor of the divider would be the insulation (or lack there of) surrounding the pumps. The other resistor would be the multimeter itself, the ground probe, or a real resistor that we put in. You can actually calculate the "resistance" of the insulation using ohms law. Let's assume that we have 25 uA of current flowing. Using ohms law then X ohms = 120 volts / 0.000025 Amps, or 4.8 Meg ohms. My multimeter is calibrated for up to 40.0 ohms, so it should be able to measure this without problems. But since it measured as an open circuit, they resistance theory can't be correct. Two notes about resistance... You'll notice that I didn't take into account the resistance of the water or the resistor that I used to make the current measurements. That's because those things have much less resistance than the estimated 4.8 meg ohms. It was a shortcut for sure, but the resistance of the water and resistor was less than 100 kohms, or about 2% of the total resistance. Also... The way most people measure the stray voltage is by placing the multimeter between the tank and earth ground. In this case, the multimeter itself acts as one resistor in the voltage divider. The multimeter has a high, but finite, resistance. That's why I used a separate resistor between the ground probe and earth ground, and measured the voltage across this resistor. The resistor was anywhere from 100 to 100k ohms. When you have a two resistors in parallel, one of low value and the other of high value, the low value resistor will be dominant. The high value resistor (the multimeter) will not play a huge electrical role and mess up the measured values. In this way, I could be assured that my measurements were correct. With capacitive coupling, you must know that a capacitor can behave like a resistor when an AC current is applied to it. The resistance is proportional to, and increases with, frequency. The formula for calculating the resistance at a given frequency is: Resistance = 1 / (2 * Pi * Freq * Cap), where resistance is in ohms, freq is in Hz, and Cap is in Farads. So, with capacitive coupling is set up exactly like the resistive coupling above but with a cap as the electrical link between the AC Mains and the water. If we expect to see a 4.8 meg ohm resistor, then we can use the above formula to find the expected capacitance. So... 4.8 meg Ohms = 1 / (2 * Pi * 60 * Cap). Solving for Cap gives us 552 pF. My multimeter will measure capacitance, but it isn't calibrated into the 1000 pF range. So I expected some "not quite right numbers". I measured the capacitance between the ground probe and hot or neutral at around 1100 pF. This was suprising, since I didn't expect the numbers to be that far off. That's when I did the "disconnect neutral and leave hot connected" experiment. In this experiment the stray voltage doubled! Then the numbers made sense. At 1100 pF, 60 Hz, and 25 uA, the resistance of the cap should be about 2.4 meg ohms. This should cause double the current to flow through our voltage divider, which causes our measured voltages to be double. The evidence matches this perfectly when neutral is disconnected. With neutral connected, the AVERAGE VOLTAGE inside the pumps, lights, etc. is exactly half of the 120 volts applied to it. That's because of the voltage drop from the current flowing through it. When we disconnect neutral, there is no current flowing so there is no voltage drop. When there is no current running through the pumps, then the average voltage is 120 volts. This explains why the voltage doubles/halves depending on the neutral connection. So, now all the evidence points to capacitive coupling! For capacitive coupling to work, a circuit must be formed. This is normally done by a ground probe (or the multimeter). If there is no circuit, then there cannot possibly be any current flowing! People claim that once they add the ground probe then they cannot measure any more stray voltage-- thus the ground probe must have removed it! This is, of course, not true. Essentially, what's happening is they are measuring the voltage drop across a zero ohm resistor (the ground probe). And of course there will be no voltage drop across such a resistor! That's why they claim that it went away. Naturally, life is more complex than that. It's not a zero ohm resistor, since you have to take into account the resistance of the water and the proximity of everything. But generally speaking, adding the ground probe will bring the measured "stray voltage" very close to zero. Conclusions: 1. Very Important! Use a ground probe and GFI for your safety. 2. "Stray Voltage" is caused by capacitive coupling, not induction. 3. There is nothing you can do about it, unless you don't use electricity in your tanks (including lights). 4. A ground probe will cause, not prevent, current from flowing in a tank. 5. The lack of current flowing has never been attributed to the death of anything (except the lack of the normal electrical impulses in the brain and nervous system). So, ground probes cannot possibly solve things like HLLE, fish stress, etc. I hope that this removes a lot of the popular myths that have been circulating for decades about stray voltages in our tanks! David Kessner "I've been employed as an electrical engineer for almost the last 20 years, and everything that David wrote is completely legit. The only claim that I can't back up is the one concerning whether electrical fields and/or currents can cause diseases in fish, but that's only becuase I don't know much about the physiology of fish.." Hans Lehmann So the issue is still unsolved on whether fish are affected or not I'm surew you will enjou all of this in this thread http://groups.google.com/groups?hl=e...1eecc.16483120 %40NEWS.erols. com&rnum=6&prev=/groups%3Fq%3Dskates%2Bgroup:rec.aquaria.marine.ree fs%26hl%3 Den%26lr%3D%26 ie%3DUTF-8%26selm%3D3601eecc.16483120%2540NEWS.erols.com%26 rnum%3D6 |
Grounding Probe ( something to read guys)
Boomer quoted Someone who wrote:
o The resistance, as measured by my multimeter, between the ground probe and neutral/hot of the pumps/lights/etc. is infinite (I.E., open). This is odd. In North America the resistance between ground and neutral should be zero as neutral is connected to ground at the power panel. The resistance between hot and ground or neutral should be infinite. Let's start with induction, since that is the common myth. The author claims there is no inductive coupling, but we know there must be. When there is a moving magnetic field (from powerheads and other pumps) there will be current flow. It may be correct to say that the inductive coupling is minimal. The other paper supports this theory. If induction were the cause, then moving the ground probe around the tank, or using two ground probes, would give us different results. This I have serious problems with. I would like to see the theory that supports the argument. |
Grounding Probe ( something to read guys)
humm stiring up the mind
SG wrote in message ... Boomer quoted Someone who wrote: o The resistance, as measured by my multimeter, between the ground probe and neutral/hot of the pumps/lights/etc. is infinite (I.E., open). This is odd. In North America the resistance between ground and neutral should be zero as neutral is connected to ground at the power panel. The resistance between hot and ground or neutral should be infinite. yea odd, is there a different way of isolating the neutral/ground/hot wires elseware i know us US ppl can be odd sometimes. Let's start with induction, since that is the common myth. The author claims there is no inductive coupling, but we know there must be. When there is a moving magnetic field (from powerheads and other pumps) there will be current flow. It may be correct to say that the inductive coupling is minimal. The other paper supports this theory. an issue for me is, even with minimal remember my issue is i had a ****ed off ray :) what you might say is minimal might be ****ing this ray off. capiable of picking up voltages well below the meters, the scope does pick up things they wont, but even then the ray might pick up even more, the people shock factor for me is seriously minimal no arms go in this tank when anything is pluged in anyways and i dont have kids to stick there hands in it. If induction were the cause, then moving the ground probe around the tank, or using two ground probes, would give us different results. This I have serious problems with. I would like to see the theory that supports the argument. I never thought that 2 ground probes would give a different result I have 2 1 in tank 1 in sump interesting worthy of closer examination i didnt place the 2nd for any reason only because i figured better safe than sorry also the scope did show different values based on where in the tank the probe was positioned maybee the meters used in his "test" were not capiable of the difference. -- richard reynolds |
Grounding Probe
Boomer wrote in message ...
LOL " mandarin goby" , yup I know what you mean Richard, but that fish has often been put in the wrong family by hobbyists, who 'think' it is Goby but actually is a Dragonet and not a Goby and whats up with that how stoned was the person that made the link between Callionymidae and dragonet and "ray fined fishes" -- Boomer :) just some minor humor mixed in with minor facts :) -- richard reynolds |
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