Poll: Grounding Probe Placement

[P-Dub]

I have one in the sump and one in the display.

I should have had that as an option in the poll. You are protected in all circumstances this way.

 

[Crabby48]

The GFCI will trip when the current in the hot leg doesn't match the current in the neutral leg. This works independent of any grounding. In fact, you can use a GFCI on old homes without grounds.

All of the grounds in the home are connected together. The neutral in your panel is also connected to ground. Since the grounds are all interconnected anyway, it doesn't matter where you plug in your ground probe. In fact, if your probe had a very long cord, you could plug it in at your neighbors house and it would work just fine.

Oh yea. I thought I was missing something. Thanks for the clarification

 

[theMeat]

I would say this is open for debate. It is definitely better to use it with a GFCI but it still does help most situations even without one.

You can't electrocute a salt water fish. The water is more conductive than they are so the vast majority of current will go around them anyway. If it is an induced voltage, current through the ground prove would only be fractions of an amp (and it doesn't matter if it is on a GFCI or not). If it is a fault voltage, current through the probe could hit 20 amps but current through the fish would still be almost nothing.

This concept is why electrofishing only works in fresh water.

You may be right.
I do home improvement and have been zapped plenty of times. When on gfci you don’t even feel it it trips so fast.
Also had tang with lateral line disease that lingered for years. Tried everything, no carbon, ground probe, still persisted. Put ground probe on gfci and in a few weeks, gone

 

[P-Dub]

You may be right.
I do home improvement and have been zapped plenty of times. When on gfci you don’t even feel it it trips so fast.
Also had tang with lateral line disease that lingered for years. Tried everything, no carbon, ground probe, still persisted. Put ground probe on gfci and in a few weeks, gone

Well, that is a good bit of info to know. Seems Tangs are pretty susceptible to stray current no matter how minor.

 

[Randy Holmes-Farley Verified Community Expert]

Maybe my bad wording in the previous post. I run half of my stuff on one gfi and breaker and the other half on a separate gfi and breaker.
How would one probe work with two separate gfi?
Won’t it only trip the gfi the probe is plugged into?
I don’t have any electrical inside my display so not concerned about if the return pump fails not being grounded. Would rather stick one in the sump and one in the return. If the return pump fails water won’t flow so the return pump area is not connected to the sump.
Please correct me if wrong

By far the most common tripping of a GFCI on my system over 20 years was failed/cracked heaters. But I did have a whole lit light fall into the display tank once when I was messing with it. Some powerheads also eventually failed and tripped the GFCI.

FWIW, GFCI are not foolproof. I pulled out a plug with salt water wet hands once (bad idea) and got a shock through my fingers. I think the current went out the hot and back down the neutral, and never had any go to ground so the GFCI didn't trip.

 

[Chrishvacman]

That is correct. The conductive sea water bonds your sump to your DT when the return pump is running.

Except for when i turn my return pump off to feed thats why i run two grounding probes.

 

[Chrishvacman]

By far the most common tripping of a GFCI on my system over 20 years was failed/cracked heaters. But I did have a whole lit light fall into the display tank once when I was messing with it. Some powerheads also eventually failed and tripped the GFCI.

FWIW, GFCI are not foolproof. I pulled out a plug with salt water wet hands once (bad idea) and got a shock through my fingers. I think the current went out the hot and back down the neutral, and never had any go to ground so the GFCI didn't trip.

Either you have a defective gfci, the current wasent great enough to trip or you did not make contact for long enough for it to trip i would imagine.

 

[Brew12]

You may be right.
I do home improvement and have been zapped plenty of times. When on gfci you don’t even feel it it trips so fast.
Also had tang with lateral line disease that lingered for years. Tried everything, no carbon, ground probe, still persisted. Put ground probe on gfci and in a few weeks, gone

Everything I have seen on lateral line disease and electricity is anecdotal and I love hearing new cases. I am still on the fence as to if there is a connection. Did the GFCI trip and help you locate a failed device?

 

[Brew12]

Either you have a defective gfci, the current wasent great enough to trip or you did not make contact for long enough for it to trip i would imagine.

This part is the key.

I think the current went out the hot and back down the neutral, and never had any go to ground so the GFCI didn't trip.

If you touch the hot and neutral at the same time, and you are insulated from ground, it will not trip the GFCI but it will hurt. A lot.

 

[theMeat]

Everything I have seen on lateral line disease and electricity is anecdotal and I love hearing new cases. I am still on the fence as to if there is a connection. Did the GFCI trip and help you locate a failed device?

Yes, turned out to be a mag drive pump

 

[theMeat]

This part is the key.


If you touch the hot and neutral at the same time, and you are insulated from ground, it will not trip the GFCI but it will hurt. A lot.

Arguably
Gfci sences small differences in the amount of power going in, to the amount going out. That’s why gfci is for shock protection, were regular breakers are designed as fire protection

 

[Brew12]

Yes, turned out to be a mag drive pump

And this is where I struggle. Was the mag drive pump leaching contaminants into the water (which it had to be if it had exposed conductors) that caused the HLLE or was it a result of the current. I don't know how to evaluate it further.

 

[Reefaddict1979]

I run one in my sump but it’s mostly for the fish and corals not me. I been keeping Fish since 1986 and never experienced a major shock so I am so worried so I feel one in the sump is enough. Maybe I am a gambler though

 

[theMeat]

And this is where I struggle. Was the mag drive pump leaching contaminants into the water (which it had to be if it had exposed conductors) that caused the HLLE or was it a result of the current. I don't know how to evaluate it further.

What I can tell you is that the same tang, with that same mag drive were first in a 72 gal. Then both moved to a 220 with a 75 gal sump. There was no noticeable dif in disease after at least a year. Which i’d Think if it was leaching there would have been

 

[Brew12]

What I can tell you is that the same tang, with that same mag drive were first in a 72 gal. Then both moved to a 220 with a 75 gal sump. There was no noticeable dif in disease after at least a year. Which i’d Think if it was leaching there would have been

It is an interesting piece of information. If I had to guess, voltage in a tank is a much bigger deal than current. Even this isn't very straight forward since voltage is normally only a problem when compared to a ground reference. Fish don't experience a ground reference so in theory 1,000V in an aquarium would impact a fish the exact same as 5V. I theorize that the problems with a fishes lateral line are due to small eddy's causing minor voltage fluctuations across them. I don't have the resources to do any solid investigation on it though.

 

[alton]

I just want to make a couple clarifications, standard GFCI's are made to trip before the amperage gets to high to kill you by tripping at 4 to 6 milli-amps. A 3-4 milli-amp shock is pretty bad and I know because when I was younger and dumber I used a bad pump, bucket of water, grounding probe, GFCI receptacle, bare feet on a tile floor, and a Fluke #771 meter to test. It was not a good feeling! Also Arc Fault breakers are made to hopefully stop a fire, regular breakers will trip by heat. If your panel is in the garage or outside in the cold, it will take much more than 20 amps to trip, which ends up resulting in burn't receptacles, plugs, and cords rated at 15 amps. I have seen that a time or two. Also use multiple GFCI receptacles, and keep your submersible return pump on it's own separate GFCI receptacle

 

[Randy Holmes-Farley Verified Community Expert]

Either you have a defective gfci, the current wasent great enough to trip or you did not make contact for long enough for it to trip i would imagine.

No, I don't think that's correct. A GFCI compares the current going out one part of the plug and back the other. If no current is lost to ground (meaning I wasn't grounded at all, insulating shoes, etc.), then it won't trip because the current flows match, and the current just pass current through my fingers. It was plenty to trip the GFCI, and the GFCI was working properly. They are just not designed to protect against this type of event.

 

[kecked]

One in sump and one in display. I've been nailed and it is no fun. PS the gyre are dc low voltage so unlikely to cause you a hurt.

 

[alton]

Your are correct Randy. If you are insulated whether it is shoes or carpet with very thick padding, current will not flow through your body. One thing I want to add is to keep their UL listing all GFCI receptacles must be self testing. So every few seconds/minutes the receptacle test itself and no longer needs you to push the button and test which means it runs through the test and doesn't like something it will trip itself, so buy quality spec grade receptacles or hospital grade and use multiple GFCI's, not just one for all. The "W" at the end stands for wet location which is a great option if your GFCI is in the cabinet

 

[P-Dub]

Your are correct Randy. If you are insulated whether it is shoes or carpet with very thick padding, current will not flow through your body. One thing I want to add is to keep their UL listing all GFCI receptacles must be self testing. So every few seconds/minutes the receptacle test itself and no longer needs you to push the button and test which means it runs through the test and doesn't like something it will trip itself, so buy quality spec grade receptacles or hospital grade and use multiple GFCI's, not just one for all. The "W" at the end stands for wet location which is a great option if your GFCI is in the cabinet

For what it is worth, the little test bottom on a GFCI breaker will tell you if the little test button works. It will NOT, I repeat, NOT tell you if your GFCI outlet is actually functioning properly. If you want to know if your GFCI is still functioning as it is supposed to, you need to purchase a separate outlet tester with an independent GFCI test button that will actually produce a ground fault in the circuit.