GFCI/AFCI Combo Receptacles?

[fulltang]

I'm in the process of researching and ordering parts for my first tank (Fluval Evo 13.5), and now I've solidly freaked myself out regarding the electrifying consequences of this hobby.

I'm deciding now if I'd rather replace my outlet or go with one of the plug-in GFCI adapters. I stumbled on these new GFCI/AFCI combo receptacles, they seem ideal, protecting both ourselves and our houses without having to mess around in the breaker box. Is anyone using these? From my research, inductive loads like refrigerators/pumps/AC units can trip them, but I don't think those are on the circuit I'll be using. I do understand that having AFCI breakers is more effective as you'll actually be protecting the wiring after the outlet, but that isn't an option currently.

Another point for replacing the receptacle is that I can then install a waterproof cover, as my tank will be pretty close to it.

My plan as of right now is to plug in anything that is submerged into the GFCI/AFCI outlet (heater, return pump, AutoAqua AWC/ATO), and anything not submerged into a different outlet (AI prime HD).

Additionally, I'll be dropping all of power cords coming out of the tank back through the stand top (desk grommet), creating a drip loop inside the stand, routing it back out the side and into the outlet. I'm also planning on coating the power cords inside the stand with something to reduce salt creep. I'm also planning on using those dog food containers with the screw on lid as my reservoirs, which should help to reduce the humidity under the tank.

No power strips or outlets will be kept inside the tank stand.

 

[Ocelaris]

I think it's a good idea, but really a breaker is much easier to replace usually than a receptacle. It may sound scary at first, but it's really not. I have had some t5 ballasts trip my gfci outlets, but once they were behind my Eb8 or a powerstrip they were fine. You can also place the combo receptacle first in line for the circuit thus protecting all downstream outlets. I highly recommend them, they've saved my butt a few times when I accidentally cut through a live wire. Instead of sparks it just did a little zap and I reset it. The only issue I've had is our microwave with an electrical "convection" (read heating element) would trip the afci, so I don't use that feature.

 

[redfishbluefish]

I think @Brew12 might be able to provide comment on this.

 

[Brew12]

I think @Brew12 might be able to provide comment on this.

Thanks for the invite!

An AFCI device is useful to protect a house but not necessarily a reef tank. It is looking for arcing in air. The GFCI will detect and trip on almost any fault in a reef tank. I wouldn't risk the added unreliability of an AFCI/GFCI outlet and would go with just a regular GFCI.

 

[fulltang]

Thanks for the invite!

An AFCI device is useful to protect a house but not necessarily a reef tank. It is looking for arcing in air. The GFCI will detect and trip on almost any fault in a reef tank. I wouldn't risk the added unreliability of an AFCI/GFCI outlet and would go with just a regular GFCI.

I see! My thinking is that I'd rather sacrifice my tank to save my house in the event that my tank leaks/overflows/salt creep/humidity/freak accident compromises a power strip or piece of equipment. I was under the impression that a GFCI outlet won't do much to protect my house in that scenario, but rather it's intended to save a person if a submerged item were to fail while you're in there. Please correct me if I'm wrong in that regard.

If I do follow best practices I should be able to reduce the chance of that scenario though, I'm just overly paranoid about electrical fires. Salt water and electricity freaks me out, man!

 

[Brew12]

I see! My thinking is that I'd rather sacrifice my tank to save my house in the event that my tank leaks/overflows/salt creep/humidity/freak accident compromises a power strip or piece of equipment. I was under the impression that a GFCI outlet won't do much to protect my house in that scenario, but rather it's intended to save a person if a submerged item were to fail while you're in there. Please correct me if I'm wrong in that regard.

If I do follow best practices I should be able to reduce the chance of that scenario though, I'm just overly paranoid about electrical fires. Salt water and electricity freaks me out, man!

You are correct that GFCI's were designed to save lives. It does that by detecting faults that include a path to ground. Almost every fault you can have in a reef tank will involve ground in some way because of the high conductivity of salt water, especially if you use a ground probe.
AFCI's are more useful for detecting faults in air in a way that it does not involve ground. This would be things like wiring connections coming lose or developing a high resistance or the hot wire arcing to its neutral. These are faults that are a real risk, but only in when air can act as an insulator to ground.

Does that make sense?

 

[Awesome Dennis]

I'd second the just get a GFCI outlet, they do make "wet rated" rated GFCI that you can consider using.

 

[fulltang]

You are correct that GFCI's were designed to save lives. It does that by detecting faults that include a path to ground. Almost every fault you can have in a reef tank will involve ground in some way because of the high conductivity of salt water, especially if you use a ground probe.
AFCI's are more useful for detecting faults in air in a way that it does not involve ground. This would be things like wiring connections coming lose or developing a high resistance or the hot wire arcing to its neutral. These are faults that are a real risk, but only in when air can act as an insulator to ground.

Does that make sense?

Yes that does make sense, thanks for the breakdown. I think I'm going to test out the combo outlet, because reducing the chance of both inside the tank and outside the tank incidents would be ideal, and hell, it's $30 to try it out. The tank won't be wet for at least another month, so I'm going to keep my eye on the combo receptacle and see how it reacts. If I notice any nuisance trips, I'll swap it out for a standard GFCI outlet. I'm also planning on isolating the GFCI/AFCI outlet so that the adjacent outlet that will be powering the light/small powerhead won't get taken out if it were to trip in the future.