severe water electrocution HELP!

[BeanAnimal]

In lay terms, the GFCI "interrupts" the current if it senses that too much current is being pulled. In other words, if there's a short and you put your hand in...the current is "drawn" to you. The GFCI will "trip" if this happens and the little "button" will pop out, instead of actually electrocuting you.

edit: L8ndeb beat me to it...damn!...lol

No, not even close

Please see my post above. The GFCI knows nothing about "too much current" or a "short". It ONLY knows how to compare the current on the HOT to that of the NEUTRAL.

Sorry to nit pik, but these are very specific devices and terms and confusion needs to be corrected so that bad information about something so serious is not propagated.

 

[BeanAnimal]

you can have either or. same function, the only reason people go with gfi outlets rather than gfi breaker is because gfi breakers are much more expensive.

There are other differences as well (trip threshhold for one).

However, there is a very good reason to NOT use a GFCI breaker.

If everything on your tank is plugged into a GFCI breaker (or single GFCI receptacle), then a single faulting device or nuisance trip will take the entire tank down!

In an ideal world we would have a GFCI receptacle for EACH critical piece of equipment. In the real world most folks can't do that, but using 2-3 GFCI receptacles and splitting your critical equipment up between them will help. In that way if a piece of equipnent faults or a GFCI receptacle nuisance trips, it will only take down the stuff plugged into it, not the entire aquarium.

 

[BeanAnimal]

would installing gfci outlets and gfci breakers be a waste of money? the second gfci would work as a redundancy in case outlet gfci failed?

It is not usually a good idea to place GFCI devices in series, as odd things can happen, or at best when something does trip it can be confusing (or dangerous) to figure out what part of the circuit is still live. I will leave figuring out the "why" as an excercise to the reader (to lazy to type anymore).

 

[Dr. Reef]

In an ideal world we would have a GFCI receptacle for EACH critical piece of equipment.

that is exactly why i have 11 legs of 110v with 11 independent breakers and all recepticles are gfi. every critical piece of equipment is plugged to an independent breaker so if one thing goes down THATS all it goes down.
i learned that from my previous tank when a faulty heater took all my tank down for 8 hrs till i got home and half of the tank didnt survive a 40F temp.

here is how its laid out.

 

[Dr. Reef]

each heater (4x300w)is on its own breaker and 110v leg, 1.5hp commercial grade chiller on its own. lights separate and skimmer is also independent.
this is what it looks like today.

 

[kv2wr1]

double post

 

[kv2wr1]

each heater (4x300w)is on its own breaker and 110v leg, 1.5hp commercial grade chiller on its own. lights separate and skimmer is also independent.
this is what it looks like today.

Very Nice setup.

 

[fishgate]

I love that the posts with the most replies are those that have the least to do with the hobby.

 

[klwheat]

No, not even close

Please see my post above. The GFCI knows nothing about "too much current" or a "short". It ONLY knows how to compare the current on the HOT to that of the NEUTRAL.

Sorry to nit pik, but these are very specific devices and terms and confusion needs to be corrected so that bad information about something so serious is not propagated.

Thanks for the clarification. I guess I should have said "loss" (difference between hot and neutral) rather than "drawn".
Nit Pikking is perfectly acceptable with topics like this imo.

 

[L8ndeb]

Not really:

The GFCI monitors current flowing in on the HOT and out on the NEUTRAL if it reads a differnece in that current, then it trips. The GFCI knows nothing about GROUND and could care less where the current "leaks" to, it just cares that it leaked somwhere. That somewhere could be ground, another circuits hot or neutral conductor, etc.

A GFCI WILL NOT protect you if YOU ARE THE LOAD. That is, if you grab the HOT WIRE with one hand and the NEUTRAL WIRE with the other. You become the load (the light bulb if you will) and the GFCI is happy becuase the current flow in equals the currnet flowing out.

(side note: lets call it a NEUTRAL not a RETURN, as the common nomenclature here in the US is NEUTRAL)

Thanks Bean.......already got schooled from Roamer

 

[IsaaX]

Furthermore DO NOT use a ground probe. Those are the work of the devil and are nothing more than a misguided fool's errand with tons of down side and ZERO 0, NO, upside - except to the unwitting fools or devious scammers selling them.

In this case a ground probe could lead to instant death of all life in the tank, possibly destruction of the tank, home, and alternatively a burned down house. I've covered how bad ground probes are in several other threads in RC already.

Yikes! I should pull mine out then! I recently got back into the hobby from a 3 year hiatus. Back then it was "the thing to do" in addition to GFCI. That's one less cord in my sump I will not have to look at. Thank you.

 

[haysanatar]

thanks for the help guys just picked up my gfci outlet and a better mulitmeter now to find the problem.

 

[BeanAnimal]

Thanks Bean.......already got schooled from Roamer

Yup... I was responding to posts as I read them, but see that many of the points were already covered. In any case, it is good to reinforce the proper information so that those who happen upon these threads are able to walk away with good information

 

[primo21]

So what was the cause of the shock?

 

[kcress]

For want of a GFI.

http://usnews.msnbc.msn.com/_news/2...ctrocuted-at-mini-golf-course-in-florida?lite

 

[madean]

Bnumair, love the idea and nice setup. Its just not always practical. But I wish I could set up like you have in the garage.

 

[Spyderturbo007]

There is on other common misunderstanding on GFCIs: they do NOT require a ground circuit to operate! In fact, NEC recommends installing GFCIs in older houses built without grounded outlets that can't easily be upgraded (remember, ground is ONLY a safety circuit, nothing more).

Does this mean that if my current outlet isn't actually grounded, that I can use a GFCI? I'm pretty sure mine aren't grounded because the little tester I plugged in lights up with "Open Ground".

So I could buy one of the GFCI's like this, plug it into the outlet and I'll be good to go?

I was considering paying an electrician to come out and run new wiring because it concerns me that the plug is right behind the sump and there is no protection. Any splash on my part and viola' wet outlet.

 

[Landsailor]

Here's why those damned ground probes are stupid, horrible ideas. (Just examples here, people.)

Voltage isn't "a thing that can kill you if you have 120 of them". It's defined as a electrical difference between two points. That's it. Point A could have a million volts behind it while Point B has the million and five volts. Measure the difference between the two points and you would see "5V" on your meter.

Let's say a loose wire falls out of your canopy and into the tank. Everything is good as long as you don't give that energy anywhere to go. You stick your hand in the tank. If there is no path through you to complete the circuit, then you would be fine.

Now, stick a ground probe in the tank. Oh look! You've just provided a nice, paved Interstate highway to give all those electrons somewhere to go.

It's the same reason why birds can land on wires and squirrels can run on them. Everything is fine as long as everything is at the same potential.

I used to work on large frame ion lasers. Incoming power was 480 volts, three phase. The tube and the transistor passbank were water cooled. The power supply rectified that three phase AC power to over 600 volts DC (or "B+" as it was called) at a significant amperage. When you measured voltages on the control cards, you made 100% sure of your reference point. Some voltages were referenced to Ground, others were to B-. Hooking your black test lead to a Gnd point when your Test Point was referenced to B- would end cause you to have A Very Bad Day. (I never did it, btw.)

So I could buy one of the GFCI's like this, plug it into the outlet and I'll be good to go?

I was considering paying an electrician to come out and run new wiring because it concerns me that the plug is right behind the sump and there is no protection. Any splash on my part and viola' wet outlet.

You could, but it's not a good idea because the outlet isn't grounded. Of course, most neutrals and grounds are bonded at the box.

The GFCI only checks the difference between the current going down the hot leg and returning via the neutral. If there is a difference, then it trips. It doesn't care if it's going down the ground wire or through you. It just sees the difference, then stops it by killing the circuit.

Ask your local Home Depot/Big Box gurus (not the "let me find that out for you" types). They may be familiar with how your house was built and could provide input. Alternatively, an experienced electrician might have fixed that issue several times before in your model of home and could provide guidance.

 

[BeanAnimal]

Does this mean that if my current outlet isn't actually grounded, that I can use a GFCI? I'm pretty sure mine aren't grounded because the little tester I plugged in lights up with "Open Ground".

So I could buy one of the GFCI's like this, plug it into the outlet and I'll be good to go?

I was considering paying an electrician to come out and run new wiring because it concerns me that the plug is right behind the sump and there is no protection. Any splash on my part and viola' wet outlet.

Yes, the GFCI will offer added protection for receptacles that do not have an earth grounding conductor.

 

[BeanAnimal]

Let's say a loose wire falls out of your canopy and into the tank. Everything is good as long as you don't give that energy anywhere to go. You stick your hand in the tank. If there is no path through you to complete the circuit, then you would be fine.

Now, stick a ground probe in the tank. Oh look! You've just provided a nice, paved Interstate highway to give all those electrons somewhere to go.

Your scenario is missing many key points.

1) the ground probe does not provide the "path through you" and in fact, even if you are barefoot on a concrete floor, provides a better path for the fault current. You may still get shocked or electrocuted, but IT IS NOT the fault of the ground probe, and if anything (in this scenario) the ground probe may (will) lessen the current through your body and/or possibly clear the fault (tripping the upstream breaker) long before you stick your arm in.

2) the ground probe IF USED IN CONJUCTION with GFCI protection will clear the fault (trip) when the broken wire falls into the aquarium. WITHOUT the ground probe, this may or may not happen depending on the grounding status of the water through other equipmnent (pump impeller shaft for expample).

Don't get me wrong, I am not a ground probe advocate. In fact, they do create potential safety issues in certain situations, especially when GFCI protection on ALL devices in or near the system is not employed.

The basic danger scenario is simple. You have a broken wire that has energized a reflector. You lean into the ungrounded aquarium (no ground probe) and you shoulder touches the reflector. You don't get shocked as there is no path for current to flow. In the same scenario with a ground probe, the current flows from the reflector, through your shoulder to your submerged hand, into the water and then to ground through the probe. You get shocked or killed. Solution DO NOT EVER USE GROUND PROBES WITHOUT FULL GFCI PROTECTION OF THE ENTIRE SYSTEM.

Again, not trying to pick on anybody, but instead tryin to ensure clarity for those that are following along.

It's the same reason why birds can land on wires and squirrels can run on them. Everything is fine as long as everything is at the same potential.

Ahh but in reality current does flow through the bird or squirrel, albiet a tiny amount. You see wire has resistance and the animal touched at 2 points and also has resistance. Electricity takes ALL paths according to their resistance, so the animal is a parallel resistor in the circuit and current does flow Nit-pik for the sake of full understanding of a "bird on a wire" analogy that is so often used in these situations

You could, but it's not a good idea because the outlet isn't grounded. Of course, most neutrals and grounds are bonded at the box.

The NEC (and sound logic dictate) that it is a good idea to replace ungrounded receptacles with GFCI devices or use cord a plug GFCI devices to add protection to the ungrounded receptacle.