Would you suggest a grounding probe?

Well I could use a little bounce in my hair... :lol: Sorry, I know this is no joking matter. I'm thinking most of the time I'll just be switching off the power strips for everything for the short amount of time required for maintenance or coral placement and on those rare occassions when I don't do that I'll test the water w/ the voltage meter to be safe. I think those two methods will guarantee I never get a new hairdoo or permanent brain damage amage... :D
 
<a href=showthread.php?s=&postid=7687842#post7687842 target=_blank>Originally posted</a> by smatter
I switch off the power before I stick my hands in the tank.
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Everytime? Really? You never need to adjust a coral, move a rock, pick up a frag, retreive a cleaning magnet, and just do so without turning off the power to the tank?
 
The setup this is all relating to isn't actually set up yet so I'm only speculating at this point on what I'm going to do vs. what I'll actually do. In my current 72 gallon I just stick my arm right in but I have very minor electrical components on that tank. I get a little tingle if I brush my arm against the PC hood while playing in the water so as of late have been making sure I don't do that... :rolleyes: I really don't forsee any issues with flipping a switch and turning everything off on the 125 though. I've had the entire system filled with tap water to test for leaks and it will actually be easier to do water changes via the sump w/ the water flow stopped. I have one of those handy dandy cleaning magnets that floats when disconnected so I just wait for it to float back on over to the glass and voila I'm back in business w/out touching the water. Other than water changes I really never have any need to put my hands in the tank as my corals get securely attached and if the tang pulls the algae clip off the glass I can easily retrieve it w/ my long scraper. (Until of course he drags it under the rocks some day just to watch the look on my face...)
 
<a href=showthread.php?s=&postid=7687851#post7687851 target=_blank>Originally posted</a> by wlagarde
If a GFCI is in use on your tank it is not possible to be injured in the process of "tripping it". The current required to trip a GFCI is far below that required to stop a human heart from beating (i.e. induce ventricular fibrillation) - hence this is why it saves lives and is reqired by code for outlets located near water. So in terms of safety a grounding probe is meaningless - HTH.
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You still get a nice little shock when a GFCI goes.

THat being said, a probe makes it so you dont have to stick your hands in to blow the GFCI. the instant a voltage leak happens, current goes to ground and it trips the GFCI. If you dont have a probe, it wont trip until you get a little shock.
 
<a href=showthread.php?s=&postid=7678475#post7678475 target=_blank>Originally posted</a> by Hal
A mere 50mA is all that it takes to stop a beating heart. Keep in mind that most circuits on your house are 20A circuits. If I did my math correctly, that's 400 times more current than you need to kill.
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Actually its around 6mA...well according to mythbusters :D
 
Again, the GFCI interrupts the circuit lfar before 20A flows. In fact, it interrupts the circuit long before even 50mA of current flows to ground, hence the idea of a GFCI breaker. So, if the GFCI is functioning, there is no hazard. And actually it's around 300mA applied at the peak of the T wave (mid-ventricular replorization) that is needed to induce V-fib. All GFCI's blow well below 100mA.
 
<a href=showthread.php?s=&postid=7689561#post7689561 target=_blank>Originally posted</a> by steve newman
Just to interject, in the uk we use Schego titanium heaters:

http://www.shopsolution.nl/shop/home.asp?shopid=seameuk&deptid=schego

which come with an earth wire ( ground ) connection coming out of the cable, in fact I use these heaters as an earth probe, which then plugs into a circuit breaker (GFCI), so are we saying I should disconnect the earth wire?.

Regards

Steve
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I havent seen that brand, but on most of the Ti heaters, the ground wire is just capped off inside. Its not even connected to the Ti shell. Its tottaly non functional.
 
<a href=showthread.php?s=&postid=7689561#post7689561 target=_blank>Originally posted</a> by steve newman
Just to interject, in the uk we use Schego titanium heaters:

http://www.shopsolution.nl/shop/home.asp?shopid=seameuk&deptid=schego

which come with an earth wire ( ground ) connection coming out of the cable, in fact I use these heaters as an earth probe, which then plugs into a circuit breaker (GFCI), so are we saying I should disconnect the earth wire?.

Regards

Steve
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Do as you choose, but you will note that Schego doesn't advertise thier heater as a "safety device".
 
<a href=showthread.php?s=&postid=7682178#post7682178 target=_blank>Originally posted</a> by bureau13
Oh look...its on a Georgia Tech website. Do they have electrical engineers there? :smokin:
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I am a Georgia Tech electrical engineer (graduated). Don't assume that means much, though. Most of those guys get squeamish if they have to do anything physical like run a wire and terminate it on a receptacle.

As for my $0.04, I would say never, ever use a ground probe without GFCI protection on all items in and above the tank. If you do, you are just creating a path to ground that will cook your tank should a piece of equipment fail and not draw at least 16 Amps (highly likely, actually). The same might happen if the GFCI fails to trip, but at least you tried to put the safety device in there. Just test your GFCI regularly to make sure it at least works off the test circuit.

Also, be aware that a low-grade insulation failure could result in a low-current flow that will not trip even a functional GFCI at 5 mA. This will still fry your tank. It will just take a little longer. That happened to a guy in my local reef club. The GFCI tested out fine, but the current was so low it would not trip. The current flow killed his sensitive corals. For that reason, I do not use a ground probe even though it would add an extra layer of safety to me, personally (alternative ground path other than your wet hand and bare feet).
 
This is very true...I'm a Purdue EE, and probably fall into that same boat! Everyone was hung up on whether or not so-and-so was an electrical engineer, when in reality an electrician would probably be far more suited to deal with this particular issue.

I get that "You're an engineer, how come you can't wire my house" BS all the time!

jds

<a href=showthread.php?s=&postid=7689960#post7689960 target=_blank>Originally posted</a> by Runner
I am a Georgia Tech electrical engineer (graduated). Don't assume that means much, though. Most of those guys get squeamish if they have to do anything physical like run a wire and terminate it on a receptacle.
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Heh. I know how to wire a house and have done so with a friend. I did not learn those skills at Tech, though. :D
 
OK what if.......

Say you have a ground probe in your tank, NO GFCI, and a shorted power head. If you are standing with bare feet in a puddle of spilled tank water, a ground probe would be a good thing to have. Right? How about if you grab some copper plumbing to balance yourself as you reach into the tank?
 
By using a grounding probe you are grounding the tank allowing electricity to flow through. If you have current running through your tank you will actually be electrocuting your fish and you if you ground it.
 
<a href=showthread.php?s=&postid=7686894#post7686894 target=_blank>Originally posted</a> by dandy7200
So if the hot wire on a powerhead comes loose in the tank, and the water is conducting current will the GFCI notice a differance and trip? Or because of the saltwaters ability to cunduct current will the water simply show the same voltage as far as the GFCI is concerned?
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Since we now have all of these EE's envolved may be one could answer this one :).
 
I imagine a grounding probe would not provide protection as the current would flow through both the grounding probe and you. Without a GFCI in both cases the current would not reach anywhere near the 20A required to blow the breaker but could provide enough current to cause death provided your feet were well grounded.
 
It is exactly as wlagarde says -- even if most of the current would flow through the low resistance path offered by the ground probe, a good bit would flow through you, too. Enough to stop a heart if it grabs you. You need a GFCI if you have a ground probe. Otherwise, the protection is marginal.

The resistance of saltwater can be too great to trip a 20A breaker. That is why the GFCI is essential. Unless it is bad, a GFCI will always notice a loose wire with bare metal of the hot wire touching the water. It is only on the high-impedence insulation break-downs (a "scuff" in the wire that doesn't quite expose the metal) that current can flow and not trip the GFCI.
 
sorry i was a little late on this thread and there are a lot of long posts that im too lazy to read, but isnt a ground probe to absorb stray current that is in the water? Thats what i use mine for. My coworker has a 10 gallon tank that had a faulty pump that was pumping 120V into his tank. it was so strong that we were getting shocked. He bought a ground probe and it absorbed all stray electricity in his tank and the volt meter is reading in milivolts
 
120v isn't that much.

In an AP Physics class I took my senior year the teacher had a machine, forgot the name of it, that would Generate 30,000 volts. You put your hand by it, it arcs through the air, you get little nip and walk away.

A grounding probe will do more harm than good. If the tank isn't grounded it doesn't matter how much current of volts are in the tank. If it becomes grounded thats when things get shocked. That is why people get shocked when they touch the water. It is because they are grounded and it provides something for the electricity to flow through.
 
Sorry guys I just don't believe that if there is current running in the tank and the water is grounded by Ti and Cu that flesh and bone is going to be the path of least resistance even if I am standing barefoot in a pool of water holding my Titanium feeding probe feeding my fish.
OK, if the problem is in the lighting and I touch a grounded tank with one hand and the light with the other there is a problem and a shock is likely, a functioning GFCI will not let that happen so I should be safe right?
Does a GFCI always see variances on the other side of a ballast?
 
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