The current will take both paths (the grounding probe and you) and if enough current flows through you then poof your dead...the GFCI will save you and yes the GFCI will sense any current that leaks to ground including that leaking from the secondary of a ballast to ground. So if the GFCI is working it will protect you. However, I would of course eliminate damaged/leaking equipment from my tank as a matter of principle.
Would you suggest a grounding probe?
- Thread starter dreaminmel
- Start date
Avast Marine
.Registered Member
I agree that eliminating faulty equipment is the best course of action regardless, I am just trying to run down the list of everything I can possibly ever forsee happening to my tank. Worst case scenerio's just like I would for plumbing. Several of you guys are providing very compelling reasons for removing the ground. I let the kids put their hands in one of my tanks and I am a stickler for safety. I want to make absolutely certain that there is NEVER a circumstance in which a ground probe could prevent a shock. I am considering removing mine as we speak. There are many thing in this hobby that are passed along as fact when indeed they may be fiction. Is this one of those? At this point I am leanig towards a definite maybe.
Runner
Active member
The ground probe will increase the saftey of people when used in conjuction with a GFCI because it will trip the circuit before you place your hand in the tank. If you are most worried about protecting people the most, then use a ground probe with your GFCI. Just be aware that you could be endandering your corals.
If 10 Amperes run to ground and 50 milliamperes through your left hand, through your heart, and to the concrete slab beneath your feet, you can still die. Current divides up with more following the path of least resistance -- not all of it.
Something I never can understand about these debates:
Why are there these debates?
Why do some of you so passionately defend your position on things you really know nothing about, when the learned knowledge of experts are so readily available? We have a difference of opinion, lets ask the electrician or in this case the electrical engineer. The only thing more rediculous is disagreeing with him.
Mike
Why are there these debates?
Why do some of you so passionately defend your position on things you really know nothing about, when the learned knowledge of experts are so readily available? We have a difference of opinion, lets ask the electrician or in this case the electrical engineer. The only thing more rediculous is disagreeing with him.
Mike
Avast Marine
.Registered Member
Not sure why you think it is a useless debate? It is a discussion on safety issues not substrate (or lack there of). MANY people use these including myself, yes I have read pros and cons in the past, but a good discussion will always be more productive then a textbook.
It is a useless debate only in that it is not a subjective issue. It like arguing if water is wet or not. I understand the curiousity or the need to know. But once an electrical person has explained it to you the debate is pretty much over.
So, as I understand, this is the nuts and bolts. Electrical power is provided via a circuit. A circuit is a loop where a hot wire sends a current out and then the current is returned through a nuetral wire. If some of the voltage escapes from the circuit and does not return down the neutral wire, it is stray voltage. In a three prong device it is returned down the ground or third prong.
If a heater were to break or a pump split in a tank that wasn't grounded then bascially nothing would happen. The current would enter the tank swim around and exit out the nuetral or ground wire per design.
Dispite commercial hype from probe sellers, the stray voltage has not been proven to cause any damage to any tank inhabitants as long as it isn't grounded.
The effects of voltage in sufficient quanities would be, using a broken heater as an example.
Grounding probe:
Current travels down the grounding probe and completes the circuit. If the heater is connected to a properly operating GFCI, the GFCI senses the differing inputs and returns and trips. If no GFCI then all the inhabitants of the tank get electrocuted and you too if you stick your hands in.
No grounding probe: Everything fine until circuit is completed by something grounding the tank. If its you then: GFCI trips if installed, no GFCI YOW! Zap. You get shocked.
Is this right?
Mike
So, as I understand, this is the nuts and bolts. Electrical power is provided via a circuit. A circuit is a loop where a hot wire sends a current out and then the current is returned through a nuetral wire. If some of the voltage escapes from the circuit and does not return down the neutral wire, it is stray voltage. In a three prong device it is returned down the ground or third prong.
If a heater were to break or a pump split in a tank that wasn't grounded then bascially nothing would happen. The current would enter the tank swim around and exit out the nuetral or ground wire per design.
Dispite commercial hype from probe sellers, the stray voltage has not been proven to cause any damage to any tank inhabitants as long as it isn't grounded.
The effects of voltage in sufficient quanities would be, using a broken heater as an example.
Grounding probe:
Current travels down the grounding probe and completes the circuit. If the heater is connected to a properly operating GFCI, the GFCI senses the differing inputs and returns and trips. If no GFCI then all the inhabitants of the tank get electrocuted and you too if you stick your hands in.
No grounding probe: Everything fine until circuit is completed by something grounding the tank. If its you then: GFCI trips if installed, no GFCI YOW! Zap. You get shocked.
Is this right?
Mike
Sorry Mike - But wrong.
In the first senario you explain, the inhabitants of the tank would not be electrocuted if there were NO GROUNDING PROBE AND NO GFCI. An exmple is the bird that sits on a 10,000 volt line without even noticing it until it touches the line AND ground - then and only then POOF.
The second case you describe is correct.
Finally - No this is not a subjective issue.
In the first senario you explain, the inhabitants of the tank would not be electrocuted if there were NO GROUNDING PROBE AND NO GFCI. An exmple is the bird that sits on a 10,000 volt line without even noticing it until it touches the line AND ground - then and only then POOF.
The second case you describe is correct.
Finally - No this is not a subjective issue.
<a href=showthread.php?s=&postid=7698820#post7698820 target=_blank>Originally posted</a> by Runner
So my bathtub can get angry an hunt me down too?
BTW, your bathtub is effectively grounded through the waste line unless it is a newer house with PVC pipe. And if you'll notice, the National Electrical Code requires all receptacles in bathrooms be GFCI protected.
More than half the homes in the US have been built with PVC plumbing and so are not grounded. GFCI's are required because thay are a safety device. Bathtub grounding is not required as it does not enhance safety.
Try again. You can ground your tub if you want, just don't claim that it is a safety device.
Runner
Active member
Um, yeah. That why I was a smartass when I answered your questions before. I am the stupid electrical engineer who refuses to trade off the safety of my fish and corals for the marginal increase in safety a ground probe would add to my person, remember? A ground probe + no GFCI = dead fish and corals on the first equipment failure.
The GFCI is required as a safety issue near water. It should be a code issue to require it on all Aquarium circuits. In fact, I think I'll submit that as a change in the 2008 NEC. Probably not applicable there, though, any more than requiring GFEP receptacles in bedrooms was (and will be replaced by other code requirements in 2008). But at least I'll get some credit for it if I do an intelligent write-up.
It is correct that this is not subjective. Electricity works exactly as it would and is 100% predictable whether you "believe in it or not". No ground (you or intentional probe or an exposed hot and neutral wire), and NO CURRENT FLOWS. There is no such thing as "stray current". It is a myth to explain the mysterious things that people don't understand. If you do not have a difference in potential, no electrons move. Just like a 1000 ton rock won't roll if it is sitting on solid, flat ground. Lot of power there, but it only does work if you roll it off the cliff and create a difference in potential. On an equipment failure in your tank, the voltage in the tank will rise to 120 Volts above ground potential at pretty much every point with no current flow except the initial minimal "charging" to bring it up to that potential. It then just sits there waiting for you to stick your hand in. No current flow occurs until you do. If you do stick your hand in, then that voltage divided by the sum of the resistances of the path between the exposed hot wire and the neutral bonding point in your power panel will determine the magnitude of current flow. If you add a ground probe, this gives you a very low resistance path back to the panel -- but still not likely large enough to trip a 20 Amp breaker (which trips at 16 Amps over a few minutes to an hour or two up to a few seconds at some point over 20 Amps). The current flow over a few hours or days will cook your tank.
That is why I say a GFCI, which operates at a difference of 5 milliamps current flow in the neutral and hot wires, is highly recommended equipment for an aquarium -- and an absolute must should you decide to use a ground probe (which I do not). The only way to be safer personally than using GFCI protection, I feel, is to develope the habit of turning off your pumps and heaters before you stick your hand in the tank. Or at the very least don't stand on a concrete floor (or wet carpet over a concrete floor) in bare feet.
dreaminmel
New member
Is all this a mute point then if I'm standing on dry hardwoods w/ slippers on? Not picking... really curious...
Runner
Active member
You are marginally safer because of the hardwood floors. That's why they are sometimes specified in electrical equipment rooms. The key is dry. If your hands are in the tank, then there will eventually be water beneath your feet. High resistance will keep current from flowing through you. It isn't exactly OSHA regulations, but rubber-soled shoes and hardwood floors and the like help out.
Plus, if you have a bad failure like a pump burning up, you could have both hot and neutral wires exposed to the tank which will give a good current flow and cause problems at least for the fish and corals in the vicinity of that pump -- not to mention the metals and chemicals being released from the incident. A GFCI will help in this case. A ground probe will just cause everything between the fault and the ground probe to cook until a GFCI takes out the circuit or (where there is no GFCI protection), the breaker eventually trips.
Plus, if you have a bad failure like a pump burning up, you could have both hot and neutral wires exposed to the tank which will give a good current flow and cause problems at least for the fish and corals in the vicinity of that pump -- not to mention the metals and chemicals being released from the incident. A GFCI will help in this case. A ground probe will just cause everything between the fault and the ground probe to cook until a GFCI takes out the circuit or (where there is no GFCI protection), the breaker eventually trips.
Avast Marine
.Registered Member
OK, I'm convinced. Ground probe coming out. Now are Ti heaters grounded to the tube?
