Grounding probes… Pros and Dangers

[OrionN]

One can connect GFCI either way. The cost of a GFCI is minimal intern of reef equipment. I think redundancy is extremely important. Spend a little more so that the tank does not suffer multiple failure at the same time is money (small amount) extremely well spend.

 

[dr_vinnie_boombatz]

I read in another thread a 3 prong titanium heater does the same thing as a stand alone grounding probe. Is this only when the heater kicks on? If it's plugged into the outlet directly vs a power strip or UPS?

 

[KStatefan]

I read in another thread a 3 prong titanium heater does the same thing as a stand alone grounding probe. Is this only when the heater kicks on? If it's plugged into the outlet directly vs a power strip or UPS?

It would be grounded all the time if everything is wired correctly.

 

[BeanAnimal]

I read in another thread a 3 prong titanium heater does the same thing as a stand alone grounding probe. Is this only when the heater kicks on? If it's plugged into the outlet directly vs a power strip or UPS?

It would be grounded all the time if everything is wired correctly.

Just be aware that many of those titanium heaters were found to not have the ground wire tied to the shell, but rather just dead ended in the cap. So, test with a meter

 

[dr_vinnie_boombatz]

Just be aware that many of those titanium heaters were found to not have the ground wire tied to the shell, but rather just dead ended in the cap. So, test with a meter

Great call; I have a IM titanium heater, but it's connected to a UPS. I'm showing 45v (no zaps ever). I wonder if it will show lower if it's plugged into the outlet directly. Also have a standalone grounding probe coming from Amazon

 

[alton]

I think everyone has covered most items, here are a couple I did not see
1. They make spec grade GFCI's that have an alarm which is fairly loud and can be heard anywhere in my home. New GFCI's are self testing so when it deems its no longer safe, it trips itself.
2a. If you are adding a grounding probe in an older home make sure your three pong receptacle is actually grounded. Went to a friends home once because he was getting shocked even though he had it on a GFCI receptacle plugged into a grounded wall receptacle and grounding probe plugged into the same receptacle. Upon further investigation some one before him had changed all the old two wire receptacles to three wire.
2b. If you use a grounding probe make sure your service is well grounded. Friend #2 was getting shocked only when he added a grounding probe to his tank. Pulled the probe out and no shock. At the same time his family felt a tingle while taking showers. Investigation found out his service was not grounded so his service was using his aquarium as a grounding means. On the showers his security contractor had used a water pipe ground which took the same current into his plumbing. I grounded the service and all issues went away.

 

[ShakeyGizzard]

Feeding the LINE side of numerous GFCIS from a circuit is perfectly acceptable and is done regularly. There is no issue with this whatsoever. GFCI #1 and GFCI #2, etc, have NOTHING to do with each other. They work independently.

True, as long as the GFCI is not connected to the load side

 

[JoJosReef]

As previously stated the circuit breaker will not protect you from electrocution or death. Voltage does not kill (the 20,000 volt engine spark plug wire will not kill you), current kills, and typically 0.1 amp (100 mA) to 0.2 amp (200 mA) through the right part of the body is lethal.

A typical 15 amp home circuit breaker could require more then 10 times the rated current (150 amps) to trip quickly. So a 15 amp breaker at 10x current can potentially produce enough current too simultaneously to kill 1,500 people before tripping! The circuit breaker will not protect you. It can cook you like a smoking hot dog before it trips.

The GFI cleverly measures the current going out one of the flat openings of the receptacle, and subtracts it from the current returning into the other flat opening, By the UL standard, if more then 0.004 amps (4 mA) to 0.006 amps (6 mA) of the return current is missing (because it potentially got diverted through a person) the GFI will instantly trip. This amount of current is well below the lethal threshold. Needless to say, ALL of our equipment in the fish room should be GFI protected so we don’t inadvertently get electrocuted!

Assuming everything is on GFI protection, the ground probe question is a little more complicated.

On one hand, if there is a defective piece of equipment in the tank leaking current, the ground probe should provide a path to divert enough current to immediately trip the GFI.

But every piece of equipment will have some measurable leakage to it, especially as it ages and after soaking in seawater. It’s possible the ground probe induces a small current path through the tank that may be too small to trip the GFI, but large enough to have a negative effect on the livestock. It’s also possible the ground probe can provide just enough of a leakage path that can inadvertently or randomly trip the GFI when no real fault exists.

The answer to the ground probe question then comes down to personal preference.

Keep in mind the normal leakage current of each piece of equipment adds up, and there is a limit to how much equipment one GFI can handle until it starts randomly tripping when no real fault exists. This is where larger systems typically require multiple GFI devices to be reliable.

You definitely want to use high quality UL approved GFI devices, and stay away from low cost junk. Also testing your outlets with a plug-in GFCI Receptacle Tester is a great idea. This will verify the Hot, Neutral, and Ground terminals of the outlet are wired correctly. Also with a push of the button, you can verify the GFI trips and is working properly.

So if you have your system on 2 different GFCI outlets, do you need a grounding probe for each GFCI? For example, grounding probe is plugged into a strip connected to GFCI outlet #1; Device in GFCI outlet #2 faults; does the grounding probe in #1 protect you or does the GFCI #2 not trip and keep sending current through your body?

 

[KStatefan]

So if you have your system on 2 different GFCI outlets, do you need a grounding probe for each GFCI? For example, grounding probe is plugged into a strip connected to GFCI outlet #1; Device in GFCI outlet #2 faults; does the grounding probe in #1 protect you or does the GFCI #2 not trip and keep sending current through your body?

The ground stays connected when the GFCI trips so you do not need one for each GFCI.

 

[dr_vinnie_boombatz]

So if you have your system on 2 different GFCI outlets, do you need a grounding probe for each GFCI? For example, grounding probe is plugged into a strip connected to GFCI outlet #1; Device in GFCI outlet #2 faults; does the grounding probe in #1 protect you or does the GFCI #2 not trip and keep sending current through your body?

I'm still learning but what I read is the probe shouldn't be connected to a strip but direct to the outlet. Does anyone know if this is true?

 

[JoJosReef]

I'm still learning but what I read is the probe shouldn't be connected to a strip but direct to the outlet. Does anyone know if this is true?

Same question here. I don't have a GFCI outlet, though (and cannot install one, not allowed). So I plan to use a GFCI plugin adapter cord with a strip plugged into thet.

At first I thought I had to plug the grounding probe into a non-GFCI outlet away from the tank. But this thead seems to indicate that the grounding probe in a non-GFCI outlet is a potential hazard...

 

[ScottD]

Same question here. I don't have a GFCI outlet, though (and cannot install one, not allowed). So I plan to use a GFCI plugin adapter cord with a strip plugged into thet.

At first I thought I had to plug the grounding probe into a non-GFCI outlet away from the tank. But this thead seems to indicate that the grounding probe in a non-GFCI outlet is a potential hazard...

The issue isn’t the grounding probe on a non gfci outlet, it’s having things plugged into a non gfci protected outlet. The gfci turns the power off in the event a short occurs. If something is plugged into a non gfci protected outlet then there is nothing to cut the flow of electricity off and current goes through the grounding probe or another way to ground. The second you put your hand in the tank, you become part of that circuit and you get electrocuted. Where if whatever is causing the short is on a gfci protected outlet as soon as it senses the short it stops electricity from flowing anymore and you can get electrocuted because there is no church it to become apart of.

As far as whether you can plug a grounding probe into a strip, I’m not sure about that. I would think it’s ok, but directly into an outlet would be better in the sense there’s less things that could get disconnected either by accident or by equipment fault and break the grounding circuit. Maybe someone else can chime in with better knowledge of that.

 

[BeanAnimal]

It does not matter what receptacle you plug the ground probe into (in theory) but you ideally want it in or near the receptacle that is feeding the equipment. While there should not be differences in ground potential throughout the electrical system, theory and real world don't always match.

 

[dr_vinnie_boombatz]

I just realized I should not be using the UPS... Wouldn't the UPS keep power on if the GFCI outlet or GFCI+AFCI circuit popped?

 

[BeanAnimal]

Yes

 

[Reefering1]

Yes

Is there any downside to plugging a gfci into a UPS? Like the outlet box with cord/ plug(like you've shared in the past) with gfci 's

 

[JoJosReef]

The issue isn’t the grounding probe on a non gfci outlet, it’s having things plugged into a non gfci protected outlet. The gfci turns the power off in the event a short occurs. If something is plugged into a non gfci protected outlet then there is nothing to cut the flow of electricity off and current goes through the grounding probe or another way to ground. The second you put your hand in the tank, you become part of that circuit and you get electrocuted. Where if whatever is causing the short is on a gfci protected outlet as soon as it senses the short it stops electricity from flowing anymore and you can get electrocuted because there is no church it to become apart of.

As far as whether you can plug a grounding probe into a strip, I’m not sure about that. I would think it’s ok, but directly into an outlet would be better in the sense there’s less things that could get disconnected either by accident or by equipment fault and break the grounding circuit. Maybe someone else can chime in with better knowledge of that.

The plan is to use two independent GFCI adapter cords in the wall outlets next to the tank:

To each these, I will connect a surge protector power strip. I also have a mini fridge containing the food and a doser the pumps food into the tank--only connection to the tank is the tubing. I was planning to connect the mini fridge to a separate non-GFCI outlet on the adjoining wall. And was also planning to plug the grounding probe into this non-GFCI outlet.

Layout:

I suppose the question is, if there is a fault on any device in Outlet #1 or #2, and I have the grounding probe in Outlet #3, will I get fried?

 

[Reefering1]

The plan is to use two independent GFCI adapter cords in the wall outlets next to the tank:

To each these, I will connect a surge protector power strip. I also have a mini fridge containing the food and a doser the pumps food into the tank--only connection to the tank is the tubing. I was planning to connect the mini fridge to a separate non-GFCI outlet on the adjoining wall. And was also planning to plug the grounding probe into this non-GFCI outlet.

Layout:

I suppose the question is, if there is a fault on any device in Outlet #1 or #2, and I have the grounding probe in Outlet #3, will I get fried?

No, because any of the gfcis will trip if it senses a imbalance of current returning on the neutral side. Regardless of where it's finding ground

 

[BeanAnimal]

Is there any downside to plugging a gfci into a UPS? Like the outlet box with cord/ plug(like you've shared in the past) with gfci 's

Not generally, ground is unbroken through the device.

 

[BeanAnimal]

I just realized I should not be using the UPS... Wouldn't the UPS keep power on if the GFCI outlet or GFCI+AFCI circuit popped?

Also, a fault on a the output of a dual conversion UPS will not trip the GFCI that the UPS is plugged into. The same holds true for a single conversion UPS on battery plugged into a GFCI, it is isolated (hot and neutral) and can’t trip the GFCI a way.