Ground probes

moviegeek · 03/11/2000, 07:27 PM

What's the consensus here on using titanium grounding probes?

Could someone briefly describe how they are installed into a tank?

Thanks,
Adam

Tadashi · 03/11/2000, 08:49 PM

Many of the devices we place in the aquarium leak voltage. I read in another post that you will not feel any shock until it is above 24 volts. Heater are the biggest culprit. I would use one just in case to prevent you or your livestock from getting shocked. $14 is a small price to pay.

I have heard someone making one out of a titanium bike spoke and old power cord but since you can get one for about $14 it may be cheaper just to buy it (unless you have those laying around your house).

As for installation - just plug into wall, if you do not have the three prong plug use the attachment and screw in the grounding screw in the wall socket plate, then place probe in tank (I put it in my skimmer sump to hide it from view).

------------------
"Honey, put the bleach down and step away from the reef tank. I promise we will spend more quality time together."
My Bonsai-reef site

David Grigor · 03/11/2000, 09:20 PM

I have heard mixed reviews.

But I have the same attitude as Tadashi. It can't hurt whether it is totatly necessary or not. It's a small price to pay.

MLP · 03/12/2000, 01:54 PM

Induced electrical charge in our tanks is still a debated topic. I for one subscribe to it as being a fact and that it has detrimental effects on our tank inhabitants. Voltages as high as 50 volts have been reported to be found in some tanks. NO you or I would not really feel this voltage as it is voltage with no amperage and no flow. However, many inhabitants in our tanks do indeed sense this voltage. Electrical voltages as small as those created by a living creatures nervous system is enough to be sensed by many waterbound creatures, as this is how some of them hunt. So placing them in an environment of a constant 25 volts would to say the least, increase stress greatly.

A grounding probe is the best way we have at controlling this. However, many people spend the $$ on one and plug it in and think they have solved the problem. This is just not true. Many homes do not have the third (ground) lead in their wall outlets. If there is no ground lead, simply screwing the wire to the screw in the middle of the socket covert 99% of the time will not provide any ground what so ever!!!!!!

If the home is old enough not to have three prong wall sockets, then the likelihood of the actual wall box being grounded is slim to nill. Furthermore if an old house that is not wired with grounds has a three prong plug installed into a wall outlet box, then there is no ground wire to connected to the ground circuit, thus it is just like a two prong plug, only you do not have to use an adapter to plug a three prong plug into it.

Has any of this made sense so far??

So, You either have to verify that you do indeed have a ground circuit in your house and at the wall plug in question. Or simply go and buy an 8" grounding rod and drive it into the ground (all the way save 6", no cheating and leaving it up a couple of feet) then run your grounding probe to the grounding rod.

HTHS

------------------
Happy Reefing,
Michael
Aquaria Central

Learn from the mistakes of others, Life is too short to make them all for yourself!
An ounce of prevention is worth a pound of cures.

myram · 03/12/2000, 03:15 PM

MLP......you have obviously not felt what 50+ volts of electricity feels like. My Rio 2500 had a crack in it's wire and was submerged in the wet/dry sump....there was 59 volts of electricity in the tank. When I went to put my hand in the tank to work on something.....whew!!! I felt it and I felt it good! I only got as far as the tip of my finger and I quickly pulled my hand out and the tip of my finger was numb. Well.....the problem fixed itself as the Rio died a couple of days later and I replaced it with a new one.

Just wanted to say.....You can feel the electricity in the tank.

------------------
http://www.angelfire.com/me3/fishtanks

MLP · 03/12/2000, 06:06 PM

myram,
Not only have I felt 50 volts, I have felt 80,000 volts and laughed about it and I have 440volts light my fire right through rubber soled shoes, and didn't laugh about it. It all depends on the amperage. An open wire in your tank has the amperage supplied by feed to your house. However, induced voltage in a tank does not, unless you have an open wire in there. And that is not what is considered induced voltage.

Another thought on utilizing a grounding probe. The use of one can virtually render a GFCI useless.

------------------
Happy Reefing,
Michael
Aquaria Central

Learn from the mistakes of others, Life is too short to make them all for yourself!
An ounce of prevention is worth a pound of cures.

JohnL · 03/12/2000, 06:13 PM

Michael, How so?

quote:
Originally posted by MLP:
Another thought on utilizing a grounding probe. The use of one can virtually render a GFCI useless.

moviegeek · 03/12/2000, 09:12 PM

I'm still reading up before I make an order at marine depot later this week. A visitor of this board was kind enough to mail me the following links:
http://nucalf.physics.fsu.edu/pfohl/...eral/grounding
http://209.185.240.250:80/cgi-bin/li...f003094%2ehtml

MLP · 03/12/2000, 11:35 PM

Hi John,
The GFCI works off the surge created in the ground side when there is a short. When you install a grounding probe it will provide an easier path to ground from your water, so if a heater breaks or (stretching it) if a lamp fixture fell into the tank the surge would flow through the probe to ground and the GFCI would not trip.

moviegeek,
Your second link doesn't work. The first link is what I am use to seeing from an electrician. They look to the obvious, and miss the obscure. I did not read the whole thing. But what I did skim on it looks only to the obvious. That being an actual leak, (like from a bare wire) of voltage into the tank. When that happens refer to my reply above to John.

However, what most electricians fail to think about is that most often the induced charge in our tanks is just that "Induced". It can come from the electromagnetic fields formed by the electric motors of PowerHeads, pumps and even heaters.

Most electricians deal with hard wires like in your house and bad wiring and overloading circuits causing most all problems. These type problems in our tanks can very quickly kill our tank inhabitants. However. EMF's create stress and hidden problems in living organisms. Just as they are finding that people that live in very close proximity to High Tension Electrical Towers have elevated health problems.

Here are a couple of things to think about:

American Society of Ichthyologists and Herpetologists have compared the electrical sensitivity of certain species of sharks to that of a voltmeter able to detect the potential between two wires connected to opposite poles of a flashlight battery, the other ends of which were separated in the ocean by a distance of two miles! By comparison to this tiny amount of electricity, the 20 volts or so measured in a tank is an enormously powerful charge. No wonder fish hide!

Also, The common dogfish, for example, finds prey by detecting its electric field, even though the prey item may be buried just beneath the sand. This does not involve a current flow, but is obviously a bio-electrical phenomenon.

This shows the sensitivity of some of the creatures that live in our WaterWorld. So anything IMHO that can be done to reduce or remove this charge in our tanks is beneficial.

Besides, A bare wire or worn insulation on a PH or Heater shoud be visible, and most would not put something like this in water, let alone their tanks anyway. A little bit of common sense always need to be employed!

------------------
Happy Reefing,
Michael
Aquaria Central

Learn from the mistakes of others, Life is too short to make them all for yourself!
An ounce of prevention is worth a pound of cures.

bmw · 03/13/2000, 07:42 AM

Hi Michael,
That was interesting about the GFI.
Why is it different to the gfi if ground is thru a "probe" rather than thru a person?
What happens if the ground probe is plugged into the gfi circuit?

Thanks,
bmw

Staceon · 03/13/2000, 07:59 AM

Does a ground probe still work if it is pluged into a "6-way" plug? The 6-way is just a type of extension plug that has six holes for plugging in with a flip switch for on/off. They are found everywhere. Does pluging the probe into it defeat its purpose?

turbo · 03/13/2000, 11:35 AM

MLP,
A ground probe in no way will render a "Properly installed" GFCI useless. I also do not agree that a GFCI works off the surge created in the ground side. A surge cannot be created from ground. A GFCI trips when there is a 5 milliamp differance between the the hot & the neutral. The GFCI wants to see 120v on the hot & 120v on the neutral, if it doesn't see that it will trip. As far as your heater/lamp scenario goes, You are correct only if the heater/lamp is on an unprotected circuit, in all likelyhood your breaker/fuse should trip(assuming it's a 15a circuit) because you would have a dead short to ground. The breaker would take time to trip though(realitively speaking) and there would be no protection to a human being if he /she were touching the water. If the breaker does not trip, there would most likely be a fire. If the heater/lamp was plugged into a GFCI at the time of breakage/falling in the tank, be it with or without a ground probe it would trip. HTH

Thanks

Paul

[This message has been edited by turbo (edited 03-13-2000).]

turbo · 03/13/2000, 11:53 AM

BMW,
Q: "Why is it different to the gfi if ground is thru a "probe" rather than thru a person?"

A: There is no diff to the GFCI as long as there is a good ground provided at the box.

Q: "What happens if the ground probe is plugged into the gfi circuit?"

A: Nothing, unless you have no ground at the box for the GFCI. At that point the GFCI will then use your tank as a ground (not good BTW). If you have a good ground they will just share the same ground.

I think of a GFCI as human protection and a ground probe as tank inhbitants protection.
HTH

Thanks

Paul

bmw · 03/13/2000, 12:14 PM

Thanks,
I asked a little tounge in cheek.
I asked an electical engineer, as well as the owner of a electical contracting firm about all this. They both told me to use a gfi circuit breaker on its own line and plug the grounding plug into it. Which I now have installed.
This was in the context of my health, not marine life.

b.

turbo · 03/13/2000, 01:17 PM

BMW,
That's exactly how I have my system wired.
Now both you and your marine life are protected

.

Thanks

Paul

Larry M · 03/13/2000, 01:47 PM

Here's the kicker: What do you do if your metal halide lights trip the gfci? I had to remove my gfi because I would come home and the tank would be dead. I tried changing the gfi, didn't help. Now that's it gone everything is rosy.

------------------
Larry M

See my tanks at Northern Reef

turbo · 03/13/2000, 01:53 PM

Larry,
Is your MH fixture grounded? Are they plugged in to a GFCI or is it a breaker?

Thanks

Paul

Larry M · 03/13/2000, 02:10 PM

The MH fixture is grounded, yes. There is a 3-prong cord on the fixture, and the ground is attached to the socket bracket. The light was connected to a gfci receptacle, now just a standard receptacle. These 175w (and maybe other wattages) 10,000K bulbs draw a ton of current when they first start up.

------------------
Larry M

See my tanks at Northern Reef

turbo · 03/13/2000, 02:49 PM

I have 2 400's, a 250 and 3 VHO ballasts on a dedicated 20amp circuit. The circuit is protected by a 20amp GFCI breaker. That breaker has never tripped. A GFCI receptacle is usually rated for 15 amps. You may want to check the fixtures' ground connection with a meter. Also check the ground at the box that the GFCI was in. Most of the electrical problems I have seen are usually bad/no grounds or bad connections. You also may want to call Leviton, they have a good tech line/customer support. Their number is on their website - www.leviton.com. HTH

Paul

bmw · 03/13/2000, 05:15 PM

FWIW,
Both the guys I consulted said a separate line with a gfi breaker. Asked about the receptcle, cord extension with the gfi--both said separate line with the gfi breaker. I do not know enough about these things--but I know both of them and their address.

I installed a separate line (15 amp btw-no mh to suck up the amps

) and no problems so far.
I did read somewhere-not a aquarium bb-- that the gfi receptcles and extensions were more prone to trip false. Again, no expertise whatsoever. Just relying on those I know who (should)have direct knowlege of the matter.
b.

Larry M · 03/13/2000, 05:29 PM

quote:
I did read somewhere-not a aquarium bb-- that the gfi receptcles and extensions were more prone to trip false.

b, I've heard that too. Being a contractor I am around electricians quite a bit. This is what they've always told me. I suppose I could fork over a few dollars and stick a gfi breaker on that circuit.

------------------
Larry M

See my tanks at Northern Reef

Dave · 03/13/2000, 05:56 PM

We need Badgers he'll set the record straight.
And for the record I was blasted once when my ground wasnt plugged in and my tank was plugged into a GFI outlet. I did have socks on and was on a cement floor. I dont think it would have happened if I had shoes on.

MLP · 03/13/2000, 08:15 PM

Your guys sure were busy here while I was still at work. A lot of stuff I will only address a bit of it.

quote:
Why is it different to the gfi if ground is thru a "probe" rather than thru a person?

Nothing, neither of those is not what the GFCI is looking for. It is looking for a fault current to ground exceeds a predetermined value. It looks for this internally within its internal circuits.

quote:
A ground probe in no way will render a "Properly installed" GFCI useless.

That was not an assumption on my part. That is what I was told by an electrical contractor. Now I am not a Certified Electrician, but I do have a pretty good knowledge base in it and it makes some sense, though I have never tried to prove or confirm it.

quote:
I also do not agree that a GFCI works off the surge created in the ground side. A surge cannot be created from ground.

Maybe a poor way that I wrote it. But yes the surge does to or through the ground side.

quote:
The GFCI wants to see 120v on the hot & 120v on the neutral, if it doesn't see that it will trip.

That is impossible because voltage is supplied in the Line side and there is no voltage supplied in the neutral side. It is just that, neutral, just the same as ground. Though properly wired, you run a separate dedicated line for ground. If you don't believe me, get out a DVOM and test your outlets yourself. Or go and pull the inside cover off your breaker box and pull your meter off as well and look how it is wired. I won't get into voltage drops and how to troubleshoot and diagnose circuits here.

Here is something taken strait off Leviton's site. Take note to what I have put in bold and italics:

quote:
Application:
These devices provide personnel protection by interrupting a circuit where a fault current to ground exceeds a predetermined value. For use with alternating current only.
A GFCI receptacle should be specified, rather than a GFCI circuit breaker, in those applications where it is important to localize power interruption, provide convenient testing and resetting at the receptacle itself (rather than at the breaker panel), minimize nuisance tripping from causes extraneous to the receptacle protected, and provide GFCI protection without specific concern for the type of manufacturer of the current overload protection.
This type of device can be installed in shared-neutral (Edison-type) circuits as long as the shared neutral ends at the GFCI. Circuit-breaker GFCI's cannot be used for such installations.

Note: In accordance with NEC Article 210-7(d), a GFCI receptacle may be used to replace an existing non-grounding 2-wire receptacle. In addition, existing non-grounding 2-wire receptacles may be replaced with grounding-type receptacles when they are supplied through a GFCI receptacle. (In this case, however, a grounding conductor should not be connected between the GFCI receptacle and those receptacles that it supplies).

I found it interesting that a GFCI receptacle may be used to replace an existing non-grounding 2-wire receptacle. I hadn't thought about it but it makes sense. Since as I mentioned above, the GFCI looks for the surge (that may be a bad word to use, but you should know what I mean) internally. So it does not require a ground connected to itself to trip. In this case it would not provide any ground protection, just power interrupt.

OK, Fire away!

------------------
Happy Reefing,
Michael
Aquaria Central

Learn from the mistakes of others, Life is too short to make them all for yourself!
An ounce of prevention is worth a pound of cures.

turbo · 03/14/2000, 01:15 AM

We are some what in agreement and I'll try to clear this up. I am not meaning to flame hear. So I'll try not to Fire.

Quote 1: Sort of in agreement. This will be looked upon at the end of this post.

Quote 2: Contractor is wrong and here is an example to support it. You are working outside next to a pool. You are using a power tool with a 3 prong plug. It is plugged into a 3 prong GFCI receptacle (code if an outlet is by a pool). What you are saying is, if you drop that electrical tool into water the GFCI will not trip because the ground(3rd prong) renders it useless. I'm sorry I can not agree with that. Even when the ground is already hard wired to the pool equipment(also code) and you are using a 2 prong plug on the tool, the GFCI will still trip. If there is a problem with a GFCI being rendered useless with a ground why is it on the receptacle?

Quote 3: When the GFCI senses a fault (5 milliamps)it trips and stops the current flow pretty much the way a breaker does. It does shunt/direct it to ground.

Quote 4: If there is a big enough voltage drop there will be an amperage draw. Once that draw hits 5 milliamps the GFCI will trip.
AC voltage does go both ways. +120vac, -120vac Hence the term AC = Alternating Current. Example: If you spliced a diode in line on the neutral wire (or the hot for that matter)on a lamp and turned the lamp on, it would blink. The reason being is you are stopping the other half of the AC signal.

Quote 5: " interrupting a circuit where a fault current to ground exceeds a predetermined value."
This statement says it all. I also think it's where the confusion is. What is meant by fault current to ground is, not the ground itself but the "fault" to ground. Usually the "fault" is a human being standing on a wet floor or touching a ground source and then touches the water when there is a problem present. That human now becomes the path to ground. Due to the natural high resistance of the human body, it's going to take some amps to push that voltage through. The higher the resistance the more amps to get the job done. With out a GFCI to shut down the power, the human is toast.

Last: Your last paragraph regarding 2 prong receptacles also tells it all. There is no ground, as you wrote "So it does not require a ground connected to itself to trip." A GFCI doesn't really look for a ground to trip. What it looks for is that predetermined value of 5 milliamps.

Quote "The GFCI works off the surge created in the ground side when there is a short. When you install a grounding probe it will provide an easier path to ground from your water, so if a heater breaks or (stretching
it) if a lamp fixture fell into the tank the surge would flow through the probe to ground and the GFCI would not trip."

The above quote contradicts itself. What you are saying is the GFCI will not trip because there is a direct short to ground. That it will not sense the surge. You were originally saying that a GFCI senses the surge in the ground side.
Here is a test to disprove that. Install a wire between the hot & ground poles right at the GFCI. All we are doing here is shortening the path a little. If what you are saying is true it will not trip. I am pretty confident that that will not be the case. Again, the GFCI is not really looking for a ground its looking for that predetermined value(a draw).

Back to the Ground probe issue.

If there is a short in a fish tank and it is GFCI protected and has a ground probe, the probe becomes the fault to ground & the GFCI will trip immediately upon reaching that 5 ma value. If it does not have a probe, the person touching the water becomes the fault to ground & it trips immediately upon reaching that 5 ma value. Either way it works, you just don't feel it the first way

. Hope this was a little clearer.

Thanks

Paul

MLP · 03/14/2000, 04:40 AM

I'm only going to address one thing right now as I am already running 15 min behind this morning.

AC current does not go both directions, it alternates on and off. This creates a sin wave that is measured in Htz.

------------------
Happy Reefing,
Michael
Aquaria Central

Learn from the mistakes of others, Life is too short to make them all for yourself!
An ounce of prevention is worth a pound of cures.

03/12/2000, 06:13 PM	#7
JohnL RC Staff Join Date: Oct 1999 Location: Long Island, NY Posts: 14,273	Michael, How so? quote: Originally posted by MLP: Another thought on utilizing a grounding probe. The use of one can virtually render a GFCI useless.

03/13/2000, 05:29 PM	#21
Larry M Moved On Join Date: Oct 1999 Location: Burnsville,MN In the heart of Reef Country! Posts: 4,544	quote: I did read somewhere-not a aquarium bb-- that the gfi receptcles and extensions were more prone to trip false. b, I've heard that too. Being a contractor I am around electricians quite a bit. This is what they've always told me. I suppose I could fork over a few dollars and stick a gfi breaker on that circuit. ------------------ Larry M See my tanks at Northern Reef

03/13/2000, 08:15 PM	#23
MLP Registered Member Join Date: Oct 1999 Location: SouthEastern, USA Posts: 50	Your guys sure were busy here while I was still at work. A lot of stuff I will only address a bit of it. quote: Why is it different to the gfi if ground is thru a "probe" rather than thru a person? Nothing, neither of those is not what the GFCI is looking for. It is looking for a fault current to ground exceeds a predetermined value. It looks for this internally within its internal circuits. quote: A ground probe in no way will render a "Properly installed" GFCI useless. That was not an assumption on my part. That is what I was told by an electrical contractor. Now I am not a Certified Electrician, but I do have a pretty good knowledge base in it and it makes some sense, though I have never tried to prove or confirm it. quote: I also do not agree that a GFCI works off the surge created in the ground side. A surge cannot be created from ground. Maybe a poor way that I wrote it. But yes the surge does to or through the ground side. quote: The GFCI wants to see 120v on the hot & 120v on the neutral, if it doesn't see that it will trip. That is impossible because voltage is supplied in the Line side and there is no voltage supplied in the neutral side. It is just that, neutral, just the same as ground. Though properly wired, you run a separate dedicated line for ground. If you don't believe me, get out a DVOM and test your outlets yourself. Or go and pull the inside cover off your breaker box and pull your meter off as well and look how it is wired. I won't get into voltage drops and how to troubleshoot and diagnose circuits here. Here is something taken strait off Leviton's site. Take note to what I have put in bold and italics: quote: Application: These devices provide personnel protection by interrupting a circuit where a fault current to ground exceeds a predetermined value. For use with alternating current only. A GFCI receptacle should be specified, rather than a GFCI circuit breaker, in those applications where it is important to localize power interruption, provide convenient testing and resetting at the receptacle itself (rather than at the breaker panel), minimize nuisance tripping from causes extraneous to the receptacle protected, and provide GFCI protection without specific concern for the type of manufacturer of the current overload protection. This type of device can be installed in shared-neutral (Edison-type) circuits as long as the shared neutral ends at the GFCI. Circuit-breaker GFCI's cannot be used for such installations. Note: In accordance with NEC Article 210-7(d), a GFCI receptacle may be used to replace an existing non-grounding 2-wire receptacle. In addition, existing non-grounding 2-wire receptacles may be replaced with grounding-type receptacles when they are supplied through a GFCI receptacle. (In this case, however, a grounding conductor should not be connected between the GFCI receptacle and those receptacles that it supplies). I found it interesting that a GFCI receptacle may be used to replace an existing non-grounding 2-wire receptacle. I hadn't thought about it but it makes sense. Since as I mentioned above, the GFCI looks for the surge (that may be a bad word to use, but you should know what I mean) internally. So it does not require a ground connected to itself to trip. In this case it would not provide any ground protection, just power interrupt. OK, Fire away! ------------------ Happy Reefing, Michael Aquaria Central Learn from the mistakes of others, Life is too short to make them all for yourself! An ounce of prevention is worth a pound of cures.

03/11/2000, 07:27 PM	#1
moviegeek Premium Member Join Date: Nov 1999 Location: Chico, CA (Nor Cal) Posts: 827	What's the consensus here on using titanium grounding probes? Could someone briefly describe how they are installed into a tank? Thanks, Adam

03/11/2000, 08:49 PM	#2
Tadashi Premium Member Join Date: Feb 2000 Location: Ft. Hood, TX, USA Posts: 2,252	Many of the devices we place in the aquarium leak voltage. I read in another post that you will not feel any shock until it is above 24 volts. Heater are the biggest culprit. I would use one just in case to prevent you or your livestock from getting shocked. $14 is a small price to pay. I have heard someone making one out of a titanium bike spoke and old power cord but since you can get one for about $14 it may be cheaper just to buy it (unless you have those laying around your house). As for installation - just plug into wall, if you do not have the three prong plug use the attachment and screw in the grounding screw in the wall socket plate, then place probe in tank (I put it in my skimmer sump to hide it from view). ------------------ "Honey, put the bleach down and step away from the reef tank. I promise we will spend more quality time together." My Bonsai-reef site

03/11/2000, 09:20 PM	#3
David Grigor Registered Member Join Date: Jan 2000 Location: Brooklyn Center, MN USA Posts: 5,030	I have heard mixed reviews. But I have the same attitude as Tadashi. It can't hurt whether it is totatly necessary or not. It's a small price to pay.

03/12/2000, 01:54 PM	#4
MLP Registered Member Join Date: Oct 1999 Location: SouthEastern, USA Posts: 50	Induced electrical charge in our tanks is still a debated topic. I for one subscribe to it as being a fact and that it has detrimental effects on our tank inhabitants. Voltages as high as 50 volts have been reported to be found in some tanks. NO you or I would not really feel this voltage as it is voltage with no amperage and no flow. However, many inhabitants in our tanks do indeed sense this voltage. Electrical voltages as small as those created by a living creatures nervous system is enough to be sensed by many waterbound creatures, as this is how some of them hunt. So placing them in an environment of a constant 25 volts would to say the least, increase stress greatly. A grounding probe is the best way we have at controlling this. However, many people spend the $$ on one and plug it in and think they have solved the problem. This is just not true. Many homes do not have the third (ground) lead in their wall outlets. If there is no ground lead, simply screwing the wire to the screw in the middle of the socket covert 99% of the time will not provide any ground what so ever!!!!!! If the home is old enough not to have three prong wall sockets, then the likelihood of the actual wall box being grounded is slim to nill. Furthermore if an old house that is not wired with grounds has a three prong plug installed into a wall outlet box, then there is no ground wire to connected to the ground circuit, thus it is just like a two prong plug, only you do not have to use an adapter to plug a three prong plug into it. Has any of this made sense so far?? So, You either have to verify that you do indeed have a ground circuit in your house and at the wall plug in question. Or simply go and buy an 8" grounding rod and drive it into the ground (all the way save 6", no cheating and leaving it up a couple of feet) then run your grounding probe to the grounding rod. HTHS ------------------ Happy Reefing, Michael Aquaria Central Learn from the mistakes of others, Life is too short to make them all for yourself! An ounce of prevention is worth a pound of cures.

03/12/2000, 03:15 PM	#5
myram 10 & Over Club Join Date: Dec 1999 Location: Biddeford, ME Posts: 384	MLP......you have obviously not felt what 50+ volts of electricity feels like. My Rio 2500 had a crack in it's wire and was submerged in the wet/dry sump....there was 59 volts of electricity in the tank. When I went to put my hand in the tank to work on something.....whew!!! I felt it and I felt it good! I only got as far as the tip of my finger and I quickly pulled my hand out and the tip of my finger was numb. Well.....the problem fixed itself as the Rio died a couple of days later and I replaced it with a new one. Just wanted to say.....You can feel the electricity in the tank. ------------------ http://www.angelfire.com/me3/fishtanks

03/12/2000, 06:06 PM	#6
MLP Registered Member Join Date: Oct 1999 Location: SouthEastern, USA Posts: 50	myram, Not only have I felt 50 volts, I have felt 80,000 volts and laughed about it and I have 440volts light my fire right through rubber soled shoes, and didn't laugh about it. It all depends on the amperage. An open wire in your tank has the amperage supplied by feed to your house. However, induced voltage in a tank does not, unless you have an open wire in there. And that is not what is considered induced voltage. Another thought on utilizing a grounding probe. The use of one can virtually render a GFCI useless. ------------------ Happy Reefing, Michael Aquaria Central Learn from the mistakes of others, Life is too short to make them all for yourself! An ounce of prevention is worth a pound of cures.

03/12/2000, 09:12 PM	#8
moviegeek Premium Member Join Date: Nov 1999 Location: Chico, CA (Nor Cal) Posts: 827	I'm still reading up before I make an order at marine depot later this week. A visitor of this board was kind enough to mail me the following links: http://nucalf.physics.fsu.edu/pfohl/...eral/grounding http://209.185.240.250:80/cgi-bin/li...f003094%2ehtml

03/12/2000, 11:35 PM	#9
MLP Registered Member Join Date: Oct 1999 Location: SouthEastern, USA Posts: 50	Hi John, The GFCI works off the surge created in the ground side when there is a short. When you install a grounding probe it will provide an easier path to ground from your water, so if a heater breaks or (stretching it) if a lamp fixture fell into the tank the surge would flow through the probe to ground and the GFCI would not trip. moviegeek, Your second link doesn't work. The first link is what I am use to seeing from an electrician. They look to the obvious, and miss the obscure. I did not read the whole thing. But what I did skim on it looks only to the obvious. That being an actual leak, (like from a bare wire) of voltage into the tank. When that happens refer to my reply above to John. However, what most electricians fail to think about is that most often the induced charge in our tanks is just that "Induced". It can come from the electromagnetic fields formed by the electric motors of PowerHeads, pumps and even heaters. Most electricians deal with hard wires like in your house and bad wiring and overloading circuits causing most all problems. These type problems in our tanks can very quickly kill our tank inhabitants. However. EMF's create stress and hidden problems in living organisms. Just as they are finding that people that live in very close proximity to High Tension Electrical Towers have elevated health problems. Here are a couple of things to think about: American Society of Ichthyologists and Herpetologists have compared the electrical sensitivity of certain species of sharks to that of a voltmeter able to detect the potential between two wires connected to opposite poles of a flashlight battery, the other ends of which were separated in the ocean by a distance of two miles! By comparison to this tiny amount of electricity, the 20 volts or so measured in a tank is an enormously powerful charge. No wonder fish hide! Also, The common dogfish, for example, finds prey by detecting its electric field, even though the prey item may be buried just beneath the sand. This does not involve a current flow, but is obviously a bio-electrical phenomenon. This shows the sensitivity of some of the creatures that live in our WaterWorld. So anything IMHO that can be done to reduce or remove this charge in our tanks is beneficial. Besides, A bare wire or worn insulation on a PH or Heater shoud be visible, and most would not put something like this in water, let alone their tanks anyway. A little bit of common sense always need to be employed! ------------------ Happy Reefing, Michael Aquaria Central Learn from the mistakes of others, Life is too short to make them all for yourself! An ounce of prevention is worth a pound of cures.

03/13/2000, 07:42 AM	#10
bmw Registered Member Join Date: Jan 2000 Location: Edge of America Posts: 905	Hi Michael, That was interesting about the GFI. Why is it different to the gfi if ground is thru a "probe" rather than thru a person? What happens if the ground probe is plugged into the gfi circuit? Thanks, bmw

03/13/2000, 07:59 AM	#11
Staceon Premium Member Join Date: Jan 2000 Location: Indianapolis, IN Posts: 2,662	Does a ground probe still work if it is pluged into a "6-way" plug? The 6-way is just a type of extension plug that has six holes for plugging in with a flip switch for on/off. They are found everywhere. Does pluging the probe into it defeat its purpose?

03/13/2000, 11:35 AM	#12
turbo Registered Member Join Date: Nov 1999 Location: San Jose CA Posts: 40	MLP, A ground probe in no way will render a "Properly installed" GFCI useless. I also do not agree that a GFCI works off the surge created in the ground side. A surge cannot be created from ground. A GFCI trips when there is a 5 milliamp differance between the the hot & the neutral. The GFCI wants to see 120v on the hot & 120v on the neutral, if it doesn't see that it will trip. As far as your heater/lamp scenario goes, You are correct only if the heater/lamp is on an unprotected circuit, in all likelyhood your breaker/fuse should trip(assuming it's a 15a circuit) because you would have a dead short to ground. The breaker would take time to trip though(realitively speaking) and there would be no protection to a human being if he /she were touching the water. If the breaker does not trip, there would most likely be a fire. If the heater/lamp was plugged into a GFCI at the time of breakage/falling in the tank, be it with or without a ground probe it would trip. HTH Thanks Paul [This message has been edited by turbo (edited 03-13-2000).]

03/13/2000, 11:53 AM	#13
turbo Registered Member Join Date: Nov 1999 Location: San Jose CA Posts: 40	BMW, Q: "Why is it different to the gfi if ground is thru a "probe" rather than thru a person?" A: There is no diff to the GFCI as long as there is a good ground provided at the box. Q: "What happens if the ground probe is plugged into the gfi circuit?" A: Nothing, unless you have no ground at the box for the GFCI. At that point the GFCI will then use your tank as a ground (not good BTW). If you have a good ground they will just share the same ground. I think of a GFCI as human protection and a ground probe as tank inhbitants protection. HTH Thanks Paul

03/13/2000, 12:14 PM	#14
bmw Registered Member Join Date: Jan 2000 Location: Edge of America Posts: 905	Thanks, I asked a little tounge in cheek. I asked an electical engineer, as well as the owner of a electical contracting firm about all this. They both told me to use a gfi circuit breaker on its own line and plug the grounding plug into it. Which I now have installed. This was in the context of my health, not marine life. b.

03/13/2000, 01:17 PM	#15
turbo Registered Member Join Date: Nov 1999 Location: San Jose CA Posts: 40	BMW, That's exactly how I have my system wired. Now both you and your marine life are protected . Thanks Paul

03/13/2000, 01:47 PM	#16
Larry M Moved On Join Date: Oct 1999 Location: Burnsville,MN In the heart of Reef Country! Posts: 4,544	Here's the kicker: What do you do if your metal halide lights trip the gfci? I had to remove my gfi because I would come home and the tank would be dead. I tried changing the gfi, didn't help. Now that's it gone everything is rosy. ------------------ Larry M See my tanks at Northern Reef

03/13/2000, 01:53 PM	#17
turbo Registered Member Join Date: Nov 1999 Location: San Jose CA Posts: 40	Larry, Is your MH fixture grounded? Are they plugged in to a GFCI or is it a breaker? Thanks Paul

03/13/2000, 02:10 PM	#18
Larry M Moved On Join Date: Oct 1999 Location: Burnsville,MN In the heart of Reef Country! Posts: 4,544	The MH fixture is grounded, yes. There is a 3-prong cord on the fixture, and the ground is attached to the socket bracket. The light was connected to a gfci receptacle, now just a standard receptacle. These 175w (and maybe other wattages) 10,000K bulbs draw a ton of current when they first start up. ------------------ Larry M See my tanks at Northern Reef

03/13/2000, 02:49 PM	#19
turbo Registered Member Join Date: Nov 1999 Location: San Jose CA Posts: 40	I have 2 400's, a 250 and 3 VHO ballasts on a dedicated 20amp circuit. The circuit is protected by a 20amp GFCI breaker. That breaker has never tripped. A GFCI receptacle is usually rated for 15 amps. You may want to check the fixtures' ground connection with a meter. Also check the ground at the box that the GFCI was in. Most of the electrical problems I have seen are usually bad/no grounds or bad connections. You also may want to call Leviton, they have a good tech line/customer support. Their number is on their website - www.leviton.com. HTH Paul

03/13/2000, 05:15 PM	#20
bmw Registered Member Join Date: Jan 2000 Location: Edge of America Posts: 905	FWIW, Both the guys I consulted said a separate line with a gfi breaker. Asked about the receptcle, cord extension with the gfi--both said separate line with the gfi breaker. I do not know enough about these things--but I know both of them and their address. I installed a separate line (15 amp btw-no mh to suck up the amps ) and no problems so far. I did read somewhere-not a aquarium bb-- that the gfi receptcles and extensions were more prone to trip false. Again, no expertise whatsoever. Just relying on those I know who (should)have direct knowlege of the matter. b.

03/13/2000, 05:56 PM	#22
Dave Registered Member Join Date: Nov 1999 Location: GURNEE IL Posts: 512	We need Badgers he'll set the record straight. And for the record I was blasted once when my ground wasnt plugged in and my tank was plugged into a GFI outlet. I did have socks on and was on a cement floor. I dont think it would have happened if I had shoes on.

03/14/2000, 01:15 AM	#24
turbo Registered Member Join Date: Nov 1999 Location: San Jose CA Posts: 40	We are some what in agreement and I'll try to clear this up. I am not meaning to flame hear. So I'll try not to Fire. Quote 1: Sort of in agreement. This will be looked upon at the end of this post. Quote 2: Contractor is wrong and here is an example to support it. You are working outside next to a pool. You are using a power tool with a 3 prong plug. It is plugged into a 3 prong GFCI receptacle (code if an outlet is by a pool). What you are saying is, if you drop that electrical tool into water the GFCI will not trip because the ground(3rd prong) renders it useless. I'm sorry I can not agree with that. Even when the ground is already hard wired to the pool equipment(also code) and you are using a 2 prong plug on the tool, the GFCI will still trip. If there is a problem with a GFCI being rendered useless with a ground why is it on the receptacle? Quote 3: When the GFCI senses a fault (5 milliamps)it trips and stops the current flow pretty much the way a breaker does. It does shunt/direct it to ground. Quote 4: If there is a big enough voltage drop there will be an amperage draw. Once that draw hits 5 milliamps the GFCI will trip. AC voltage does go both ways. +120vac, -120vac Hence the term AC = Alternating Current. Example: If you spliced a diode in line on the neutral wire (or the hot for that matter)on a lamp and turned the lamp on, it would blink. The reason being is you are stopping the other half of the AC signal. Quote 5: " interrupting a circuit where a fault current to ground exceeds a predetermined value." This statement says it all. I also think it's where the confusion is. What is meant by fault current to ground is, not the ground itself but the "fault" to ground. Usually the "fault" is a human being standing on a wet floor or touching a ground source and then touches the water when there is a problem present. That human now becomes the path to ground. Due to the natural high resistance of the human body, it's going to take some amps to push that voltage through. The higher the resistance the more amps to get the job done. With out a GFCI to shut down the power, the human is toast. Last: Your last paragraph regarding 2 prong receptacles also tells it all. There is no ground, as you wrote "So it does not require a ground connected to itself to trip." A GFCI doesn't really look for a ground to trip. What it looks for is that predetermined value of 5 milliamps. Quote "The GFCI works off the surge created in the ground side when there is a short. When you install a grounding probe it will provide an easier path to ground from your water, so if a heater breaks or (stretching it) if a lamp fixture fell into the tank the surge would flow through the probe to ground and the GFCI would not trip." The above quote contradicts itself. What you are saying is the GFCI will not trip because there is a direct short to ground. That it will not sense the surge. You were originally saying that a GFCI senses the surge in the ground side. Here is a test to disprove that. Install a wire between the hot & ground poles right at the GFCI. All we are doing here is shortening the path a little. If what you are saying is true it will not trip. I am pretty confident that that will not be the case. Again, the GFCI is not really looking for a ground its looking for that predetermined value(a draw). Back to the Ground probe issue. If there is a short in a fish tank and it is GFCI protected and has a ground probe, the probe becomes the fault to ground & the GFCI will trip immediately upon reaching that 5 ma value. If it does not have a probe, the person touching the water becomes the fault to ground & it trips immediately upon reaching that 5 ma value. Either way it works, you just don't feel it the first way . Hope this was a little clearer. Thanks Paul

03/14/2000, 04:40 AM	#25
MLP Registered Member Join Date: Oct 1999 Location: SouthEastern, USA Posts: 50	I'm only going to address one thing right now as I am already running 15 min behind this morning. AC current does not go both directions, it alternates on and off. This creates a sin wave that is measured in Htz. ------------------ Happy Reefing, Michael Aquaria Central Learn from the mistakes of others, Life is too short to make them all for yourself! An ounce of prevention is worth a pound of cures.