Aquarium and electrical safety

[BeanAnimal]

Can we sum this all up in an article for people like me who don’t understand any of it?

I will have something formal published in a few days. @revhtree

I am driving, but if somebody can find my post above and relink it here, I laid out the basics.

 

[Reefering1]

I will have something formal published in a few days. @revhtree

I am driving, but if somebody can find my post above and relink it here, I laid out the basics.

Code now requires one or the other (AFCI or GFCI) depending on circuit designation and service location for most circuits (beyond the scope of this conversation). The scope expands with each code revision.

AFCI breakers can be problematic with motor, ballast and some switch mode power supply loads. Sadly, they are also ideal for things like arcing in a power strip caused by salt creep. So, a dilemma for aquarium owners.

If you want Arc Fault protection, then either a combo AFCI/GFCI breaker can be used or an AFCI breaker with GFCI receptacles.

While nuisance trips can be catastrophic for the tank, they added protection with regard to personal safety may be worth the risk.

Ignoring nuisance trips and ground probe debates and focussing on HUMAN safety:

At the very minimum I would suggest ground fault protection (RCD in other parts of the world) for all of the equipment that services the aquarium. Either breakers or receptacles. Both are effective.

Arc fault circuit breakers add a protection against arcing shorts. They could detect some power strip failures.

Many power strips fail because they melt and catch fire before the breaker sees enough current to trip. The culprit is often salt creep either direct or due to evaporating drips. The arc fault breaker may or may not see this, since AFCIs detect line-to-neutral or line-to-ground arcing but not always carbon tracking or parallel leakage through salt. The later is a common cause of failure. The parallel leakage through the salt (the same as carbon tracking) produces tremendous amounts of heat without tripping the breaker. The heat melts the power strip, allowing the contacts to loosen, generating even more resistance and heat. The result is often an non-arcing fault that creates a fire. Commercial quality power strips can help to reduce the risk. They have a metal frame with real NEMA 5-15 receptacles instead of soft plastic bodies that hold cheap copper bus strips. the metal frame is grounded and will trip the GFCI and the UL rated NEMA receptacle will not melt (nearly as easily).

A ground probe (only if you have GFCI protection). This will allow the GFCI to detect fault current in the tank and trip the breaker before you ever put your hand in the water. Without GFCI protection, a ground probe increases hazard.

Use only actual UL/CSA listed equipment and avoid China knock offs. While they may have agency listings, they are often fake. You should be able to find the UL/CSA listing for the device at the agency website. Also be aware that many manufacturers will use a UL listed component and build their unlisted device around it, then fraudulently display the device as listed. So stick with well regard name brands with traceable certifications.

As mentioned above a simple receptacle tester can confirm polarity and basic miswire. If you find an issue, call an electrician. This is very important if you have more than one circuit feeding your aquarium. If the circuits are on two different legs from your panel then there is 220 V of potential between the hot conductors, not just 110 V.

While balancing load to the panel is important, I would recommend that if you are going to use 2 or 3 branch circuit breakers for redundancy, that they be on the same leg. This limits fault voltage potential to 110V.

Always be aware of the risk. Test GFCIs regularly. To be sure, the "test" button on a GFCI does test the device by sending fault current through the comparator. If the test button fails, the device has failed and needs to be replaced.

Be aware of your surroundings. ALWAYS Inspect for salt creep, leaks, UV damaged or physically damaged wires.

Use the one hand rule when possible. One hand in the tank, one at the side or behind the back. Stand on dry, insulated flooring. Shocks are unpleasant, but a shock through the arms crosses the heart and can be deadly, even at low current.

Note that the uninsulated body (bare feet on concrete, arm in the tank for example, ) would allow the GFCI to trip of no ground probe were used, but that is a risk not worth taking. Use the ground probe to route fault current, not potentially (no pun) your body. Without a ground probe and with an insulated body, the fault may not clear (trip the GFCI) but you don't get shocked either.

Never ground the tank to multiple different grounds or an isolated ground. The ground probe MUST go to the ECG (ground pin or wire) feeding a receptacle. If there us more than one ground probe, ground them all to the same common spot.

Assume that epoxy potted pump motors (cheap power heads, AC magdrive pumps, etc.) will eventually fail and may create a fault if submerged. So plan to replace them on some fixed schedule before they shock you or trip the GFCI.

NEVER fully submerge the head of a heater. The heater should be placed in a fixed water-level compartment with the head out of the water. Prefer heaters that have a test tube shape instead of those with two open ends that are plugged. NEVER allow a heater to run dry. If it does, throw it away.

Circuit breakers are not meant to protect you. They protect the branch circuit wire. GFCIs are meant to protect you.

Lastly, where possible use low voltage DC equipment. While DC is still dangerous, many of our DC devices pose far less risk than their AC counterparts. This goes back to cheap China stuff though. Ensure the DC power supplies are properly isolated. Cheap converters with AC leakage are dangerous. So avoid the $10 wall warts and use reputable DC supplies (Meanwell for example).

The UPS basically negates the upstream GFCI. If it does sense the fault and trip, the UPS will activate and reenergize the fault. The output side of the UPS can be GFCI protected, but that is not straight forward. Many UPS system have no earth reference on battery, so a line to earth fault does not flow more than a few mA of current. It is a floating system. However when not on battery the downstream GFCI would be in series with the upstream GFCI. Nuisance trips are almost a certainty. This is a complex subject and very dependent on chosen equipment.

The ground probe provides a current path to ground. When used with GFCI protection, the device will trip if there is a fault.

Used without GFCI protection, you create (in theory and in practice) a danger that did not otherwise exist.

Let me briefly explain five variations of the same scenario.
Scenario:
You have a light fixture over the aquarium that has faulted. The metal case of the fixture is "hot" because somewhere inside of the fixture, the hot wire is touching the metal enclosure. The light happily chugs along without tripping the breaker.

You reach into the tank to do some work, your ear (or shoulder) or whatever touched the metal fixture.

1 - NO GFCI and NO GROUND PROBE. You are wearing rubber soled shoes.
In theory, no current flows. There is no path through your body to lower potential even though your hand is in the tank and your ear or shoulder touching something energized by a fault. The situation is still very dangerous, but the tank and your body have no path to ground.

2 - NO GFCI but there IS A GROUND PROBE. You are wearing rubber soled shoes.
In theory and practice you are going to get shocked. Current will travel from the fixture through your ear (or shoulder), then through your wet hand and out through the ground probe. YOU become the connecting wire.

3 - GFCI protection with A GROUND PROBE. You are wearing rubber soled shoes.
In theory and in practice you are going to get a minor shock that you may or may not feel. The moment that your body becomes the "wire" the GFCI will sense the fault and trip, saving your life.

4 - GFCI protection WITH or WITHOUT A GROUND PROBE. You are barefoot. Same protection as #3. The moment that your body completes the circuit, the GFCI trips to protect you.

5 - NO GFCI and NO GROUND PROBE and you are barefoot. You don't need to touch the tank, the moment you touch the fixture, you get shocked!

A GFCI compares the current flowing out on the hot conductor to the current returning on the neutral. Any difference means current is leaking somewhere else. So, possibly through you or water, and it trips.

UL 943 specifies that a GFCI must trip when the imbalance is between 4 mA and 6 mA.

Such leaks are called faults and may result from real insulation faults. They may also not be actual faults, but rather small capacitive or inductive leakage inherent to normal devices.

If a single device is connected, it can leak up to about 4 mA before tripping. Large transformers (think MH ballasts), capacitors (LED power supplies), or motors (pumps) with poor power factor can cause brief transient imbalances when energized.

When many aquarium devices share one GFCI, each may leak a small amount (often < 1 mA) of current. This is normal and expected. However putting say, ten devices on a single GFCI might total 3.5 mA of normal leakage. A short inrush event adding just 2 mA raises the total to 5.5 mA, exceeding the trip threshold.

Most homes have GFCI breakers or a single GFCI receptacle fed from a standard breaker. The single GFCI breaker or receptacle feeds multiple outlets resulting in “downstream” protection. This makes nuisance trips common for complex systems like our aquariums where we cram pieces of equipment onto a single GFCI. The better approach is to have an electrician install multiple GFCI receptacles or circuits so equipment groups are isolated. That limits nuisance trips and keeps critical gear running when another branch trips.

Extension cord and plug-in type GFCI adaptors are often more prone t nuisance tripping. They are typically set to the lower end of UL 943 (closer to 4 mA) and often often more sensitive (not a bad thing) to transients than dedicated NEC approved devices. Also many "trip" when unplugged to prevent a power tool from coming back on after a power failure.

Here is drawing I made years ago that may show the setup a but clearer.

 

[W31Olds]

Bean, you clearly know what you're talking about, however I would proceed with Caution when authoring articles about "Electrical Safety" as they could expose you and this site to liability. Safety information is extremely important when setting up/working in wet areas for both SW and FW Aquariums and needs to be discussed to increase awareness for new and experienced Hobbyists. I would make sure you have a consensus that the information is correct and the proper disclaimers before posting.

 

[W31Olds]

when the hobby started in the US in1970 we didn't have gfis. we also didn't have any submersible anything. no powerheads or heaters that were completely submersible. what we did have was salt creep because we used air stones which covered everything in salt so we quickly learned to turn on the light with a stick and unpl.ug everythng before we put our hands in the tank.

you also couldnt buy a ground probe so i just bent a silver or stainless steel knife or fork around the rim of the tank and connected a wire to it that went to the screw that held the receptable in.

that grounding method worked flawlessly then and i still use the same system.

eventually, if you keep submersible devices in the tank long enough, the cord will crack where it enters the device allowing full 120 volts of electricity into the water.

that frayed wire (or cracked pump housing) will try to draw all 15 or 20 amps from your panel, depending on the size of the circuit breaker.
if you had that ground probe on there, the breaker will trip and you will be safe.

if it were not for that circuit breaker, the wires would melt all the way from your tank, through the walls back to the panel and would even melt part of the panel.


thank god we have circuit breakers.
but a circuit breaker is a mechanical device and depends on heat to trip so it could take a second or two to trip. as an electrician i have seen this dozens or hundreds of times. before we had testing tools for this. if we wanted to find the breaker a receptable was on, we just bent a wire and shoved it into the outlet to short it out.

then we would go and look for the tripped breaker. this was in office buildings in Manhattan so there were thousands of breakers.

anyway, many times the circuit breaker wouldn't trip right away, and the wire would heat up to almost melting. hopefully brakers are built better now.

the old glass plug fuses were a lot safer but were very cheap, so people were talked into breakers. of course, now we use gfis which can't be used with fuses.

because of the lag in a breaker to turn off the power we now use gfis.
have 3 on my tank so they dont all rip together.

this thing on amazon seems awfully cheap at $19.00 so i have no opinion about it

Eaton TRAFGF15LA AF, Arc Fault/GF, Ground Fault Dual -Purpose, Duplex Receptacle with wallplate 15A 125V LA​

---

Paul, when I first had Tanks as a Teen, I knew almost nothing about Electricity and the Hazards when working on my SW Tanks. I still cringe today thinking about all the fluorescent lamps I had sitting on top of my Tanks with salt creep everywhere and heaters clamped to the back. And grounding, what was that. Funny, I don't remember ever getting zapped at least not badly. Did get hit a few times during my early years working as a Test Technician. 400HZ AC smarts.

 

[Paul B]

olds as an electrican i got zapped dozens of times. more than i would like to remember. we always worked on live circuits, even on the huge bus bars on buildings like the empire state bldg, chrysler building, and world trade center.

those buildings run on 480 volts. we lost so many electricians that now electricans dont work live any more.

i still do but now i dont work on those buildings as i am retied

sorry about the typing

 

[Garf]

Is there such a device as a consumer ready aquarium water voltage monitor?Something reef safe and waterproof? If not, you’re welcome for the idea to make it.

I don't know, but wouldn't a pH meter be severely effected by AC?

 

[vlangel]

A GFCI compares the current flowing out on the hot conductor to the current returning on the neutral. Any difference means current is leaking somewhere else. So, possibly through you or water, and it trips.

UL 943 specifies that a GFCI must trip when the imbalance is between 4 mA and 6 mA.

Such leaks are called faults and may result from real insulation faults. They may also not be actual faults, but rather small capacitive or inductive leakage inherent to normal devices.

If a single device is connected, it can leak up to about 4 mA before tripping. Large transformers (think MH ballasts), capacitors (LED power supplies), or motors (pumps) with poor power factor can cause brief transient imbalances when energized.

When many aquarium devices share one GFCI, each may leak a small amount (often < 1 mA) of current. This is normal and expected. However putting say, ten devices on a single GFCI might total 3.5 mA of normal leakage. A short inrush event adding just 2 mA raises the total to 5.5 mA, exceeding the trip threshold.

Most homes have GFCI breakers or a single GFCI receptacle fed from a standard breaker. The single GFCI breaker or receptacle feeds multiple outlets resulting in “downstream” protection. This makes nuisance trips common for complex systems like our aquariums where we cram pieces of equipment onto a single GFCI. The better approach is to have an electrician install multiple GFCI receptacles or circuits so equipment groups are isolated. That limits nuisance trips and keeps critical gear running when another branch trips.

Extension cord and plug-in type GFCI adaptors are often more prone t nuisance tripping. They are typically set to the lower end of UL 943 (closer to 4 mA) and often often more sensitive (not a bad thing) to transients than dedicated NEC approved devices. Also many "trip" when unplugged to prevent a power tool from coming back on after a power failure.

Thank you BeanAnimal for explaining this. I knew the GFCI circuits that a tank was on could trip seemingly for no reason but never knew why this was. I also found once a GFCI tripped a number of times it was likely to trip more often. That happened with my tank so eventually I removed the GFCI and did not replace it (which now I realize how dangerous that really is).
I am rethinking all this. My tank is very simple with no sump. Right now it has a HOB filter but that will be replaced with a canister. It has 2 vortechs so there is no electricity in the water. I have plugged in the heater and the Carefree Fish wavemaker (which are the only 2 pieces of equipment with electrical components in contact with the water or that I would touch when I am in contact with the water) into a power strip that I will turn off when I am in the tank. That should reduce the risk greatly. Am I thinking about this right?

 

[Sophie"s mom]

Grounding probe with GFCI yes!

Yes BRS titanium heaters act as grounding probe. Any titanium heater with a 3 prong plug.

Wearing rubber sole shoes and maybe even placing stool on a rubber mat?

This is interesting to me! So recently I bought a BRS titanium heater with a Helios universal controller. SO are you saying this serves the same purpose as a grounding probe? That is awesome if so.

 

[jonelder68]

This is interesting to me! So recently I bought a BRS titanium heater with a Helios universal controller. SO are you saying this serves the same purpose as a grounding probe? That is awesome if so.

Yes it will act as a grounding probe. But as Bean mentioned a batch were sent out without having the ground bonded. Would have to test heater with a volt meter and a continuity test from ground pin of heater to the case/body.

 

[Sophie"s mom]

Yes it will act as a grounding probe. But as Bean mentioned a batch were sent out without having the ground bonded. Would have to test heater with a volt meter and a continuity test from ground pin of heater to the case/body.

Do we know when that batch was sent out? I got this heater maybe 2 months ago.

 

[BZOFIQ]

Yup, I just grabbed a quick diagram off google.

I went one step further and installed a bank of remote GFCI switches on the wall few feet from the tank so that I don't have to fiddle with GFCI buttons underneath the stand.

http://url.xoomer.com/gfci

Here are my blank face GFCIs mounted on a wall in a closet few feet away from the tank. Dry, easy to reach and reset if needed. Not if your tank is already in place but if you're in planning stages - these are really nice.

I used different brands to see if one had less of a failure rate and perhaps false tripping. That said, neither has tripped once in past 2 years. Very happy.

Amazon.com

The other side as previously shown is behind the stand/tank.

Or a more realistic view

 

[jonelder68]

Here are my blank face GFCIs mounted on a wall in a closet few feet away from the tank. Dry, easy to reach and reset if needed. Not if your tank is already in place but if you're in planning stages - these are really nice.

I used different brands to see if one had less of a failure rate and perhaps false tripping. That said, neither has tripped once in past 2 years. Very happy.

Amazon.com

The other side as previously shown is behind the stand/tank.

Or a more realistic view

Top notch work Love it! I also didn’t know about the GFCI without integration into an outlet. That could be useful in many situations.

 

[jonelder68]

Do we know when that batch was sent out? I got this heater maybe 2 months ago.

@BeanAnimal any idea when these batches went out? Regardless it would still be a good idea to check. I’ll see if I have time tonight to document the procedure of testing them.

 

[Paul B]

mine isnt as neat. this is only showing half of the devices plugged in.



And we don't want this. this is what happens when a plug gets wet. and the gfi may not trip depending on which prongs get wet.



this is how houses burn down

 

[Sophie"s mom]

@BeanAnimal any idea when these batches went out? Regardless it would still be a good idea to check. I’ll see if I have time tonight to document the procedure of testing the

@BeanAnimal any idea when these batches went out? Regardless it would still be a good idea to check. I’ll see if I have time tonight to document the procedure of testing them.

That would be amazing! I am not the least bit electrically savvy! I can change an outlet, or install a ceiling fan, but that's about as far as it goes.

 

[Freenow54]

The bottom line is that I have posted numerous times about this subject when are people going to take any advice given by anyone and avoid a tragic event like what we were unfortunately talking about just common sense is enough you don't need understanding

 

[Freenow54]

mine isnt as neat. this is only showing half of the devices plugged in.



And we don't want this. this is what happens when a plug gets wet. and the gfi may not trip depending on which prongs get wet.



this is how houses burn down

That is the exact situation an arc protector will prevent

 

[Paul B]

That is the exact situation an arc protector will prevent

maybe not, it depends on some variables.

 

[Jay Hemdal Verified Community Expert]

Ignoring nuisance trips and ground probe debates and focussing on HUMAN safety:

At the very minimum I would suggest ground fault protection (RCD in other parts of the world) for all of the equipment that services the aquarium and receptacles that are close to the aquarium, regardless of use. Either breakers or receptacles. Both are effective.

In fact, I would suggest that people who can afford it, hire an electrician to upgrade breakers in their panel to AFCI/GFCI types as prescribed in the current NEC code. The rules evolve over time and are based on historical data regarding shock, electrocution and fire. The rules are not retroactive, so it is up to you to request upgrades.

Arc fault circuit breakers add a protection against arcing shorts. They could detect some power strip failures.

Many power strips fail because they melt and catch fire before the breaker sees enough current to trip. The culprit is often salt creep either direct or due to evaporating drips. The arc fault breaker may or may not see this, since AFCIs detect line-to-neutral or line-to-ground arcing but not always carbon tracking or parallel leakage through salt. The later is a common cause of failure. The parallel leakage through the salt (the same as carbon tracking) produces tremendous amounts of heat without tripping the breaker. The heat melts the power strip, allowing the contacts to loosen, generating even more resistance and heat. The result is often an non-arcing fault that creates a fire. Commercial quality power strips can help to reduce the risk. They have a metal frame with real NEMA 5-15 receptacles instead of soft plastic bodies that hold cheap copper bus strips. the metal frame is grounded and will trip the GFCI and the UL rated NEMA receptacle will not melt (nearly as easily).

A ground probe (only if you have GFCI protection). This will allow the GFCI to detect fault current in the tank and trip the breaker before you ever put your hand in the water. Without GFCI protection, a ground probe increases hazard.

Use only actual UL/CSA listed equipment and avoid China knock offs. While they may have agency listings, they are often fake. You should be able to find the UL/CSA listing for the device at the agency website. Also be aware that many manufacturers will use a UL listed component and build their unlisted device around it, then fraudulently display the device as listed. So stick with well regard name brands with traceable certifications.

As mentioned above a simple receptacle tester can confirm polarity and basic miswire. If you find an issue, call an electrician. This is very important if you have more than one circuit feeding your aquarium. If the circuits are on two different legs from your panel then there is 220 V of potential between the hot conductors, not just 110 V.

While balancing load to the panel is important, I would recommend that if you are going to use 2 or 3 branch circuit breakers for redundancy, that they be on the same leg. This limits fault voltage potential to 110V.

Always be aware of the risk. Test GFCIs regularly. To be sure, the "test" button on a GFCI does test the device by sending fault current through the comparator. If the test button fails, the device has failed and needs to be replaced.

Be aware of your surroundings. ALWAYS Inspect for salt creep, leaks, UV damaged or physically damaged wires.

Use the one hand rule when possible. One hand in the tank, one at the side or behind the back. Stand on dry, insulated flooring. Shocks are unpleasant, but a shock through the arms crosses the heart and can be deadly, even at low current.

Note that the uninsulated body (bare feet on concrete, arm in the tank for example, ) would allow the GFCI to trip of no ground probe were used, but that is a risk not worth taking. Use the ground probe to route fault current, not potentially (no pun) your body. Without a ground probe and with an insulated body, the fault may not clear (trip the GFCI) but you don't get shocked either.

Never ground the tank to multiple different grounds or an isolated ground. The ground probe MUST go to the ECG (ground pin or wire) feeding a receptacle. If there us more than one ground probe, ground them all to the same common spot.

Assume that epoxy potted pump motors (cheap power heads, AC magdrive pumps, etc.) will eventually fail and may create a fault if submerged. So plan to replace them on some fixed schedule before they shock you or trip the GFCI.

NEVER fully submerge the head of a heater. The heater should be placed in a fixed water-level compartment with the head out of the water. Prefer heaters that have a test tube shape instead of those with two open ends that are plugged. NEVER allow a heater to run dry. If it does, throw it away.

Circuit breakers are not meant to protect you. They protect the branch circuit wire. GFCIs are meant to protect you.

Lastly, where possible use low voltage DC equipment. While DC is still dangerous, many of our DC devices pose far less risk than their AC counterparts. This goes back to cheap China stuff though. Ensure the DC power supplies are properly isolated. Cheap converters with AC leakage are dangerous. So avoid the $10 wall warts and use reputable DC supplies (Meanwell for example).

Thanks for your post.

I took your advice to heart and replaced ALL pumps and heaters in my home office tank, as well as got a plug in GFCI. This tank has been running with no real maintenance (aside from water changes) since 2018. I replaced one pump last year due to split insulation on the cord, but upon inspection, all cords that have been submerged are now very stiff. I had replaced the cheap power strip with a commercial grade UL listed one last year.

 

[jonelder68]

Thanks for your post.

I took your advice to heart and replaced ALL pumps and heaters in my home office tank, as well as got a plug in GFCI. This tank has been running with no real maintenance (aside from water changes) since 2018. I replaced one pump last year due to split insulation on the cord, but upon inspection, all cords that have been submerged are now very stiff. I had replaced the cheap power strip with a commercial grade UL listed one last year.

Cheap power strips are scary! I had one charging my kids power wheels in the garage. Picked it up to move it and heard a rattle from it. Next thing I know it’s smoking I dropped it and has about a foot tall flame coming off it with sparks. Luckily my main breaker panel is in the garage so I could easily kill the power.