Grounding probes… Pros and Dangers

[Enrique7]

I dont normally use grounding probes. Mostly because of the fear of completing the cycle and frying everything including me. My reasoning is based on the idea that if I accidentally drop a bare light, pump.. connector of unknown voltage I would complete the circuit and increase the danger of electrocution. So does it only help with low stray voltage?
What are your thoughts ?

 

[KrisReef]

The ground is designed to be the shortest distance to the earth with the idea that you will be a slightly longer path to the earth and the undesirable electricity will not go through you for the most part.

Even if you think you are in the fast lane the ground is going to keep you safe

 

[Solo McReefer]

Hopefully it goes to ground, via the ground rod

Not through you

And pops the breaker

Low voltage is better of course, but will still make you see stars if you get zapped

Ask me how I know this

And learn about what the Smoke Theory of Electricity is. It applies to people too

 

[Reefer Matt]

Only use them with a gfci outlet. This will trip the tank if the equipment shorts out. Otherwise a fire or electric shock can occur in the event of a short. If the gfci keeps tripping, then some equipment is bad. I’d rather lose the tank than myself and/or my home. I have five tanks that are all their own gfci circuit with a ground probe.

 

[Solo McReefer]

I don't know about that "only with a gfci" thing

That's a first I've heard that

A working breaker, at the breaker box, will pop on ground. Or should. If not, that needs to be replaced

 

[Reefer Matt]

I don't know about that "only with a gfci" thing

That's a first I've heard that

A working breaker, at the breaker box, will pop on ground. Or should. If not, that needs to be replaced

The breaker won’t trip unless the amperage rating is exceeded. You can be killed or a fire started well before that happens. A gfci will trip the circuit before that happens. I encourage everyone to have their tanks on a gfci circuit. Ask your local electrician for advice on equipment needed for electricity and water. Especially saltwater.

 

[LARedstickreefer]

The breaker won’t trip unless the amperage rating is exceeded. You can be killed or a fire started well before that happens. A gfci will trip the circuit before that happens. I encourage everyone to have their tanks on a gfci circuit. Ask your local electrician for advice on equipment needed for electricity and water. Especially saltwater.

I’LL second this.

-Matt

 

[BeanAnimal]

Hopefully it goes to ground, via the ground rod

Not through you

And pops the breaker

Low voltage is better of course, but will still make you see stars if you get zapped

Ask me how I know this

And learn about what the Smoke Theory of Electricity is. It applies to people too

A breaker is not designed or meant to protect you, it is only there to protect the wire.

GFCI are there to protect you.

 

[BeanAnimal]

I don't know about that "only with a gfci" thing

That's a first I've heard that

A working breaker, at the breaker box, will pop on ground. Or should. If not, that needs to be replaced

You should NEVER put a ground probe in a tank unless all of the equipment in and near the tank is GFCI protected.

 

[Solo McReefer]

That seems like it's more ALWAYS use GFCI around tanks

I'm trying to see this in my head

Ungrounded salt water tank. Everything electrical fully insulated. Nothing metal in the tank. The tank is fully insulated

A stray hot white wire, non GFCI 15 amp circuit, goes in the tank. Nothing happens, right? It's effectively air insulated

You stick your hand in the tank, that voltage goes to ground through you. A little of you're wearing rubber soled shoes. Most of it if you're barefoot and standing on a drip of saltwater on the floor, and the smoke comes out

Correct me where this is wrong, please

[Let pretend I don't have GFCI for everything for the tank, in this scenario. I do in real life]

 

[BeanAnimal]

No GFCI. Insulated tank. Faulted light fixture. Rubber shoes. Hand in tank. Face touches fixture. Maybe a tingle maybe not.

No GFCI. Grounded tank. Faulted light fixture. Rubber shoes. Hand in tank. Face touches fixture. You are the wire. You die.

GFCI. Insulated or grounded tank. Faulted light fixture. Any shoes or bare feet. Hand in tank. Face touches fixture. GFCI trips. You live to eat bacon another day.

That is one of many dangers using a ground probe and no GFCI. Ground probes in an aquarium scenario create acute dangers that would not otherwise exist if they are used without full GFCi protection in and near the aquarium.

Again, a circuit breaker has nothing to do with personal protection against shock or electrocution. It is a safety device sized to protect the wire on the circuit, not you or the utilization equipment.

 

[Solo McReefer]

Question

Those text features you just used, I used to have. Now they are disabled. You wouldn't know how to turn them back on, would you?

 

[BeanAnimal]

Question

Those text features you just used, I used to have. Now they are disabled. You wouldn't know how to turn them back on, would you?

No clue. Sorry.

 

[Enrique7]

You should NEVER put a ground probe in a tank unless all of the equipment in and near the tank is GFCI protected.

Ok. Thats what I was thinking and I actually dont have everything on GFCIs. Should I? Is the safest way to have everything on GFCIs and a grounding probe?
What about false trips or faulty gfcis? I am trying to find the safest way without messing with a currently working system.
I mostly have mp40s and I dont need a heater, however, i do have 3 returns and about 20 light fixtures with hanging cables near water

 

[RelaxingWithTheReef]

Ok. Thats what I was thinking and I actually dont have everything on GFCIs. Should I? Is the safest way to have everything on GFCIs and a grounding probe?
What about false trips or faulty gfcis? I am trying to find the safest way without messing with a currently working system.
I mostly have mp40s and I dont need a heater, however, i do have 3 returns and about 20 light fixtures with hanging cables near water

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.

 

[KStatefan]

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.

That is also how you eliminate the GFCI as a single point of failure. Spread items among several GFCIs.

 

[KrisReef]

Question

Those text features you just used, I used to have. Now they are disabled. You wouldn't know how to turn them back on, would you?

Supporting member benefit?

 

[vetteguy53081]

I dont normally use grounding probes. Mostly because of the fear of completing the cycle and frying everything including me. My reasoning is based on the idea that if I accidentally drop a bare light, pump.. connector of unknown voltage I would complete the circuit and increase the danger of electrocution. So does it only help with low stray voltage?
What are your thoughts ?

While an alternative than a solution, I run probes full time

 

[Doctorgori]

I can’t count how many times a light fixture fell in the tank with my hands or arm in it … or how many times I’ve been shocked ( just got zapped btw from a cheap Amazon UV)

Water, electricity and no GFCI, You have entered the Darwin sweepstakes …
GFCI yes, no ground probes yet but should have

 

[Tamberav]

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.

I’m in an apartment and use a plug in GFCI that I found at Home Depot around $10 or $15. They seem to work but is there something you would advise to use since you mention high quality? It’s an apartment so I cannot change the outlets but I wasn’t sure if there was specific high quality plug in ones?