Aquarium and electrical safety

[BeanAnimal]

Nah it’s been beat to death. GFCI or be fried. I mean pretty basic principles

He is not asking if he should use a GFCI. He is asking for help with nuisance trips. If you are unhappy with the thread, then remove yourself from it instead of complaining.

 

[Reefering1]

Nah it’s been beat to death. GFCI or be fried. I mean pretty basic principles

And what exactly are you adding to this discussion? Move on.

 

[KJoFan]

I should also mention this tank has been up and running since Feb of 2025. Issues just started in December 2025 with no obvious changes to equipment. @BeanAnimal

 

[jsmkmavity]

Has the electrician triple verified that there isnt a neutral from another circuit connected in one of the outlet boxes? Ground wires have to all be tied together in a box but not neutral wires. If neutral wires from 2 different circuits are connected anywhere in the circuit it will cause an afci breaker to trip but not always consistently. This is an easy mistake to make and to correct, but it can take some time to track down. I apologize if i missed some info by not reading the whole thread that would make my question irrelevant, just offering a possible helpful suggestion

 

[KJoFan]

Has the electrician triple verified that there isnt a neutral from another circuit connected in one of the outlet boxes? Ground wires have to all be tied together in a box but not neutral wires. If neutral wires from 2 different circuits are connected anywhere in the circuit it will cause an afci breaker to trip but not always consistently. This is an easy mistake to make and to correct, but it can take some time to track down. I apologize if i missed some info by not reading the whole thread that would make my question irrelevant, just offering a possible helpful suggestion

No, that has not been checked. But, I'll make a note of it to mention next time he's here. I appreciate the suggestion!

 

[Freenow54]

GFCI trip threshold is ~6 mA

Various devices can have tiny amounts of leakage current or capacitive losses the look like leakage to the GFCI.

Any single devices contribution to the budget may not trip the GFCI, but the combined leakage may be enough to push it close to the threshold and a device with poor power factor or high inrush current may push it past, causing a nuisance trip.


Your electrician‘s explanation is dumb, but he is correct in stating that the AFCI can’t be removed and replaced with GFCI only. Code requires the AFCI in most rooms now.

What he can do is replace the AFCI/GFCI breaker with an AFCI only model, and then add multiple parallel GFCI receptacles in the fish room, allowing you to split critical loads onto different GFCIs.

Did you ask the electrician to tell you if the trips were AFCI or GFCI?
Per the breaker you showed.

Square D HOM120PDFC dual-function AFCI/GFCI (CAFCI + GFCI).
Per the Square D docs:

How to tell what caused the trip on this breaker:

Look at the Indicator light (small LED window):
Red blinking = GFCI trip
Amber/yellow = blinking AFCI trip
Solid red = Self-test failure or breaker failure
No light = Overcurrent (thermal/magnetic) trip or breaker off

I think of you already reset from last trip you can still see by pressing test and looking at the led.

Dam you stole my point I was going to post that this morning. That's great your explanation is beautiful.. Allow me to qualify myself . I worked in HVAC ( heating ventilation , and AC ) I actually have an AC Refrigeration ticket but to describe my self as a refrigeration technician would be and I think for anyone would be ridiculous . I knew a few people who actually made their own refrigeration fluids . The tangents of that trade are mind boggling. . I did put goldfish in liquid O2 once though . Anyway long way around to the point I experienced about three times where renos were done after finally being at the furnace when the breaker popped. Someone with a nail gun in one case split the wire right between the conductors causing an intermittent short. So something to think about when you do diagnose the breaker . Also I don't know if this would cause a trip but you did not mention if you have aluminium wiring . If so there is a conductive gel in any case that should be applied to the bare wire and use a special mar ret . Also not a bad exercise to shutoff the breaker take all the receptacle covers off and check the mar ret tightness. If I remember correctly in the panel all the wire nuts are torqued to 31. If I have a point would not mind someone else verifying . The renovation thing is real though

 

[KJoFan]

GFCI trip threshold is ~6 mA

Various devices can have tiny amounts of leakage current or capacitive losses the look like leakage to the GFCI.

Any single devices contribution to the budget may not trip the GFCI, but the combined leakage may be enough to push it close to the threshold and a device with poor power factor or high inrush current may push it past, causing a nuisance trip.


Your electrician‘s explanation is dumb, but he is correct in stating that the AFCI can’t be removed and replaced with GFCI only. Code requires the AFCI in most rooms now.

What he can do is replace the AFCI/GFCI breaker with an AFCI only model, and then add multiple parallel GFCI receptacles in the fish room, allowing you to split critical loads onto different GFCIs.

Did you ask the electrician to tell you if the trips were AFCI or GFCI?
Per the breaker you showed.

Square D HOM120PDFC dual-function AFCI/GFCI (CAFCI + GFCI).
Per the Square D docs:

How to tell what caused the trip on this breaker:

Look at the Indicator light (small LED window):
Red blinking = GFCI trip
Amber/yellow = blinking AFCI trip
Solid red = Self-test failure or breaker failure
No light = Overcurrent (thermal/magnetic) trip or breaker off

I think of you already reset from last trip you can still see by pressing test and looking at the led.

The breaker I linked to must not be exactly the same. There is no LED indicator on the breakers I have.

 

[BeanAnimal]

If it is SqaureD homeline then you turn breaker off, hold test button and turn back on while holding test

https://download.schneider-electric...t&p_File_Name=HRB86114.pdf&p_Doc_Ref=HRB86114
To read a fault from a Square D Homeline AFCI/GFCI breaker, turn it OFF, then hold the white "TEST" button while flipping the breaker ON; it will trip instantly for a ground fault, after ~2 seconds for an arc fault, or after ~5 seconds for a thermal/short circuit, indicating the last fault type detected.

It holds the memory of the last trip for 27 days.

 

[KJoFan]

If it is SqaureD homeline then you turn breaker off, hold test button and turn back on while holding test

https://download.schneider-electric...t&p_File_Name=HRB86114.pdf&p_Doc_Ref=HRB86114
To read a fault from a Square D Homeline AFCI/GFCI breaker, turn it OFF, then hold the white "TEST" button while flipping the breaker ON; it will trip instantly for a ground fault, after ~2 seconds for an arc fault, or after ~5 seconds for a thermal/short circuit, indicating the last fault type detected.

It holds the memory of the last trip for 27 days.

Per those instructions, it tripped immediately. Which still confuses me. If it's a ground fault, why didn't the breaker with GFCI outlets I ran on for 10 days never trip?

 

[BeanAnimal]

Per those instructions, it tripped immediately. Which still confuses me. If it's a ground fault, why didn't the breaker with GFCI outlets I ran on for 10 days never trip?

Hard to tell, not all GFCIs are exactly the same. The GFCI in the combo breaker may be a bit more sensitive than that in the single purpose breaker. Different generations, etc.

This goes back to multiple devices possibly contributing to an elevated baseline due to their combined signatures (real or capacitive leakages) individually being below the trip threshold, but combined at or near it and a bit of fluctuation pushing it over.

It could also be an intermittent actual fault on one of your devices.

If it were me, I would have the AFCI breaker instead of the combo AFCI/GFCI and then utilize several GFCI receptacles, removing the single point of GFCI failure.

 

[KJoFan]

Hard to tell, not all GFCIs are exactly the same. The GFCI in the combo breaker may be a bit more sensitive than that in the single purpose breaker. Different generations, etc.

This goes back to multiple devices possibly contributing to an elevated baseline due to their combined signatures (real or capacitive leakages) individually being below the trip threshold, but combined at or near it and a bit of fluctuation pushing it over.

It could also be an intermittent actual fault on one of your devices.

If it were me, I would have the AFCI breaker instead of the combo AFCI/GFCI and then utilize several GFCI receptacles, removing the single point of GFCI failure.

That all makes sense. Next time it trips off I'll call the electrician (that was our arrangement) and propose the route you suggest.

If we go the multiple GFCI receptacle route, would there still be capacity to add equipment to that circuit in the future or am I to assume I'm capped at the current level?

 

[Paul B]

Hey Bean. I'm glad I retired 20 years ago so I don't have to mess with these AFCI breakers. I am not a big rule follower, so I removed most of the GFIs from my house except for the places near water and my tank.

They are probably required all over the place but it's stupid in most cases. Remember, the people who write the code are not electricians but pencil pushers.

If I ever move again, and I doubt it, I will just take 10 minutes and put them back in.

 

[BeanAnimal]

Hey Bean. I'm glad I retired 20 years ago so I don't have to mess with these AFCI breakers. I am not a big rule follower, so I removed most of the GFIs from my house except for the places near water and my tank.

They are probably required all over the place but it's stupid in most cases. Remember, the people who write the code are not electricians but pencil pushers.

If I ever move again, and I doubt it, I will just take 10 minutes and put them back in.

With the last code adoption (2023/24), just about ALL areas of the home require AFCI with few exceptions. I think unfinished basements and garages may not need them, but everywhere else does. The 2026 revisions are going to tighten even further. No "new" additions, but rather broader scope to application past residential.

GFCI has expanded a bit, but is still mostly kitchen, wet location, garage, outdoors, etc.

So whole home AFCI and much of home combo AFCI/GFCI. I don't think any single 120V receptacle in the home is exempt from one or the other or a combo. I am fairly sure that even lighting circuits now now required to be AFCI and fire alarm circuits are only exempt if they are EMT (or maybe MC also).

They also have refused to allow for exceptions for certain types of equipment, even if dedicated I think other than temporary outdoor HVAC equipment Basically they say "if the AFCI nuisance trips, take it up with the appliance vendor, the code will not permit exceptions".

 

[Paul B]

Well, after you move in, an inspector will never have to come and look at anything. At my age, I don't really care what the code says.

 

[BeanAnimal]

Well, after you move in, an inspector will never have to come and look at anything. At my age, I don't really care what the code says.

You are grandfathered... er your panel I mean.

No AFCIs on aquariums here either.

 

[KJoFan]

@BeanAnimal Tank and equipment has been running without a trip now since Tuesday.

EB832 controlling the two 350w heaters remains on a separate GFCI circuit.

Of course, the AFCI/GFCI the tank itself is on could still trip. But, I'm starting to think with everything on one circuit there is enough cumulative leakage to exceed the trip threshold.

If that is indeed the case, is the solution still AFCI breaker and multiple GFCI receptacles, but still on the same circuit?

 

[BeanAnimal]

@BeanAnimal Tank and equipment has been running without a trip now since Tuesday.

EB832 controlling the two 350w heaters remains on a separate GFCI circuit.

Of course, the AFCI/GFCI the tank itself is on could still trip. But, I'm starting to think with everything on one circuit there is enough cumulative leakage to exceed the trip threshold.

If that is indeed the case, is the solution still AFCI breaker and multiple GFCI receptacles, but still on the same circuit?

Two or three circuits are always a better idea with regard to redundancy.

My choice would be 2 or 3 AFCI breakers with several GFCI receptacles on each. What is ideal and what you can achieve may not be the same thing.

 

[KJoFan]

Two or three circuits are always a better idea with regard to redundancy.

My choice would be 2 or 3 AFCI breakers with several GFCI receptacles on each. What is ideal and what you can achieve may not be the same thing.

Well, I'll probably try to see if I can go the AFCI breaker route, add a second circuit and at least a couple GFCI receptacles on each circuit. I don't know that much more than that is feasible just based on logistics.

ETA: I guess current results don't explain why it just started tripping in December, but not the months previously.

 

[jsmkmavity]

I dont know your total load and havent seen the list of everything plugged in but breakers of any type as well at gfci outlets (receptacles) when operated at or near their capacity can get "weaker" over time and once they start tripping and getting reset they often start tripping easier. I cant remember if you said you have a new breaker that also tripped? I would still be looking at all cords and entrance points of heaters/pumps/powerheads that are in water or susceptible to salt creep for possible failure while you wait for electrician to track down other possibilities. Sometimes even the housing on a pump can crack or isnt completely sealed and water can get in that way too.

 

[BeanAnimal]

I dont know your total load and havent seen the list of everything plugged in but breakers of any type as well at gfci outlets (receptacles) when operated at or near their capacity can get "weaker" over time and once they start tripping and getting reset they often start tripping easier.

Just to be precise:

A thermo-magnetic breaker (your panel breaker) may "weaken" after numerous thermal (overload) trips, but the threshold is fairly high, as in many dozens or hundreds of thermal overload trips. This has no effect on magnetic short circuit (think of a solenoid) trips, only thermal overload trips.


GFCI/AFCI receptacles or breakers do not "weaken" or have a lower trip threshold after multiple activations. The trip mechanism is solid-state logic and acts on a magnetic solenoid that trips the breaker receptacle. In the case of the breaker, there is no wear to the thermal mechanism.