Your Resident Electrician for all your electrical questions!

[Ebone]

question? Do I need a gfci outlet, or can I install a gfci breaker and be covered just as well? Is there a downside?

 

[Brew12]

You would be just fine with a GFCI breaker. Some people prefer them because they are considered less likely to fail.

 

[Ebone]

You would be just fine with a GFCI breaker. Some people prefer them because they are considered less likely to fail.

good to know was curious why everyone talks about changing the oulet, when can do the breaker and be done easy everywhere

 

[RamsReef]

good to know was curious why everyone talks about changing the oulet, when can do the breaker and be done easy everywhere

Outlet is cheaper.
Outlet is lower risk of shock. Working off of single de-energized cct vs working in panel.
Outlet can protect all additional outlets downstream from it, if you need it too.

There really is no reason to use a breaker.

 

[Joey waid]

good to know was curious why everyone talks about changing the oulet, when can do the breaker and be done easy everywhere

If it was me, I would change the breaker.....

 

[Ebone]

cheaper and aquarium always seems to lead to failure haha

 

[Brew12]

Outlet is cheaper.
Outlet is lower risk of shock. Working off of single de-energized cct vs working in panel.
Outlet can protect all additional outlets downstream from it, if you need it too.

There really is no reason to use a breaker.

One very good reason I have seen is when people cannot access a receptacle behind the tank. It is easier to change the breaker to GFCI than to find an upstream receptacle and change it out.

 

[Ebone]

One very good reason I have seen is when people cannot access a receptacle behind the tank. It is easier to change the breaker to GFCI than to find an upstream receptacle and change it out.

that is my situation, i have an gfci outlet thingy but would rather have the breaker

 

[RamsReef]

To each their own.

 

[LParker480]

Outlet is better for isolating and if tripped, upstream outlets would remain on. Depending on whats connected where, that could be pretty vital.

 

[Turbo's Aquatics]

Alright here is a good question....

Some people subscribe to the thought process that their return pump(s) should not be on a GFCI, the logic being that even if there was a ground fault in the system, it's better for the fish to have a circulating water supply. But, we also want to have awareness to the aquarist about this situation occurring.

So what about this: add a GFCI to the system, somewhere "downstream" of the outlet that feeds the pumps. Perhaps, just for use on a single small device, like another small pump for a reactor or skimmer or something. Plug one device into the GFCI and the ground probe into it as well.

Now, what happens when there is a ground fault on another device in the system? The way I see it, this would not trip the GFCI because the fault needs to happen on what is connected to the device itself. So in essence, placing a ground probe on a GFCI that is at the tail end of the circuit run can actually act like the scenario where you have a ground probe and no GFCI, which can lead to this:

Scenario 1. Hot line to water via submerged equipment. This is when a submerged piece of equipment like a powerhead, heater or UV lamp fails and the hot line of the power supply gets in contact with the water:

c) GROUND PROBE INSTALLED BUT NO GFCI (Our case of discussion in this thread): As soon as the device fails and a short circuit is established then current is established to the ground probe, current may or may not be high enough to trip the breaker. Fish and critters will die and corals will RTN. If the breaker does not trip (Which is most of the cases) the short circuit may not be noticeable and you will be at a loss of why your critters are dying, even if you touch the water you may not notice unless the ground probe is not making a good ground. (See also Scenario 3c below) This is also a dangerous situation for potential fire. The current could be high but not high enough to trip the breaker, wires heat up, insulation melts and they catch fire.

or this

Scenario 2: Short circuit between hot line and neutral on submerged equipment:

c) Ground probe installed but no GFCI: Same situation as in 2a above but if a secondary short is created current will be established killing the tank inhabitants but just probably faster than the toxic chemicals or copper compounds. Here you are dependent on the breaker.

or this

Scenario 3: Short circuit from hot to a metal part of a non-submerged device and there is no current to trip the device as the metal body is not grounded: This is typical of a lighting fixture to whom one of the light bulb wires touches the reflector or the metallic hood or when some of the wiring of external pumps short to the pumps body and the body of the pump is not grounded.

c) Ground probe and no GFCI: This is one of the the main reasons why probes shall not be installed unless a GFCI is also installed. The water will be perfectly grounded. If you are working in the water and touch the device you will get badly shocked or electrocuted even is you yourself are electrically insulated by the use of rubber soles or such.

or this

Scenario 5: Short from Neutral to water: As usually the neutral wire is grounded either at the outside were the wires enter the house or at the main nothing happens unless this neutral grounding is not perfect some small voltage may develop creating the following situation:

c) Ground probe but no GFCI: The small voltage may create a permanent small current, this may be enough to start killing the most sensitive critters, (Pods and Snails) and create coral RTN over long term.

So basically, is there any "safe" in-between scenario?

 

[Brew12]

Now, what happens when there is a ground fault on another device in the system? The way I see it, this would not trip the GFCI because the fault needs to happen on what is connected to the device itself. So in essence, placing a ground probe on a GFCI that is at the tail end of the circuit run can actually act like the scenario where you have a ground probe and no GFCI, which can lead to this:

I really want to take more time to dig into this and address what you have written, including the older post you have referenced. Unfortunately, I don't have time to get into that right now. The one thing I do want to quickly say is that where the ground probe plugs into the system has no impact on any fault conditions. All of the house grounds, including properly designed power strips that are plugged in, should always be connected and are not disconnected by a GFCI opening. A GFCI also does not care where the ground current flows since it doesn't measure ground current. If the faulted device is inside the zone covered by the GFCI it will trip even if the ground probe is plugged into a separate circuit on the house. If the faulted device is on an outlet before the GFCI, no GFCI trip will occur even if the ground probe is plugged into a GFCI protected outlet.

 

[Turbo's Aquatics]

Right...that was my point, I guess.

Obviously, if the faulty device trips the GFCI, it will no longer have power, thus no current (from that device's fault) would go through the ground probe.

This basically raises the issue of GFCI & ground probe when all devices are not on the GFCI. This is a situation where one could think they are protected, when in fact they are not, and in a way that specifically could start a fire under certain circumstances.

Kinda leads you to the "all or nothing" type of philosophy. Either you have everything on GFCI and then have a ground probe, or you only have certain devices on GFCI and no ground probe. But you can't have it both ways.

Seems like the missing element here is a current sensor on the ground...something that wouldn't shut everything off, but would sound an alarm to let the aquarist know that something is not right = don't reach into the tank!

 

[Brew12]

Right...that was my point, I guess.

Obviously, if the faulty device trips the GFCI, it will no longer have power, thus no current (from that device's fault) would go through the ground probe.

This basically raises the issue of GFCI & ground probe when all devices are not on the GFCI. This is a situation where one could think they are protected, when in fact they are not, and in a way that specifically could start a fire under certain circumstances.

Kinda leads you to the "all or nothing" type of philosophy. Either you have everything on GFCI and then have a ground probe, or you only have certain devices on GFCI and no ground probe. But you can't have it both ways.

Seems like the missing element here is a current sensor on the ground...something that wouldn't shut everything off, but would sound an alarm to let the aquarist know that something is not right = don't reach into the tank!

Personally, I feel that the fear of high current from using a ground probe without a GFCI is overblown. If you have a heater or motor casing crack, the water will short between the the hot to the neutral. In this case, the neutral is the exact same thing as a ground probe.
It's issues like this that make me want to really dig into this.

 

[RamsReef]

Safe go between:
Use an external return pump not on a GFCI.
If you are so concerned about a faulty pump on a gfci tripping then get an external pump.

Windings in a motor block are still going to be laminated. So you have to have, failure of motor block, failure of windings (Although easily corroded by salt water).

If I absolutely could not put in a GFCI but decided to add a ground probe I would not connect it (ground it), instead I would use it as a fault indicator and connect one end of the ground to a light bulb or led and the other to ground. My selected voltage would probably be 48v to signal fault situation.

The reason we see power bar and outlets destroyed (Fire) is because the fault is not staying on the typical conductive parts of the power system. The fault is establishing across plastics which in turn heat up, break down, oxidize?(Turn to carbon) and further conduct.


Scenario 1: Probably going to be very low current. Would not use this scenario, would use ground as indicator.
Scenario 2: I'm going to assume H-N short in same device. Current should be high enough to trip breaker unless you are talking about a turn-turn fault in a motorblock, or something like that.
Scenario 3: Against code to have a non grounded metal body, non scenario.
Scenario 5: Should not do anything unless house is wired incorrectly (Switched neutrals on lights) and another cct raises neutral potential.

 

[Brew12]

If you are so concerned about a faulty pump on a gfci tripping then get an external pump.

If I absolutely could not put in a GFCI but decided to add a ground probe I would not connect it (ground it), instead I would use it as a fault indicator and connect one end of the ground to a light bulb or led and the other to ground. My selected voltage would probably be 48v to signal fault situation.

These are both fantastic suggestions!

 

[Turbo's Aquatics]

If you are so concerned about a faulty pump on a gfci tripping then get an external pump.

Curious: why does this make a difference? Can't an external pump have a situation that would trip a GFCI?

 

[Brew12]

Curious: why does this make a difference? Can't an external pump have a situation that would trip a GFCI?

It can, but since the pump isn't in the tank it will not leak voltage/current into the tank.

This is the same basis as for why I use MP40's in my DT. The motors aren't in the tank and I consider them more important to my tanks short term health than my return pump. So my return pump is GFCI protected but my MP40's are not.

 

[JBradford]

Electrical question and it has nothing to do with a tank. I have a 220v line (3 pin) running to my kitchen for an electric range, however, I have a gas range that does not use the 220v plug. I also don't foresee me going to an all electric range.....ever.

I want a 220v outlet in my garage for a compressor (4 pin).

I have everything to run this 4 pin outlet. I do not have an extra spot in my panel for a breaker to run a dedicated line to my compressor.

Can I safely 'tap' into the 220v line in the attic and run it over to my garage? If so, do I need to change my compressor over to a 3 pin plug to make this an easier/safer installation?

 

[RamsReef]

Curious: why does this make a difference? Can't an external pump have a situation that would trip a GFCI?

An external pump will not be subjected to constant contact with salt water and will more than likely never fail. (The motor windings that is, not the bearings, pump seal, etc.)
Furthermore if it does fail (windings) it will be a winding/winding short and will cause an increase in motor temperature which (Should) trip the internal motor overloads, or further cause an upstream breaker to trip.
If you wanted to GFCI your external motor you would be looking for a condition where there is a winding to case fault. This would have to be in the near the bottom of the winding to not cause the overloads to trip and would probably place your motor case at such a low voltage you would not notice if you touched it anyways.


I for one would follow somthing close to @Brew12 design if you are concerned about loosing water circulation on a gfci trip, where in your return pump and wave makers are on separate gfci ccts or separated somehow. It will not be the return pump stopping that kills the inhabitants, it will be the lack of surface exchange.
Furthermore for the ultra paranoid you could hook a 120VAC relay up to the same power as your return pump. Then take the NC connection of said relay to power up a 12/24 pump or fan connected to a battery bank. Should the power shut off to said relay the contacts will close powering up your fan or pump that will agitate the surface of the water.
Or buy 2 pumps.
Or train a fish to swing valves in case of a pump failure.