07-31-2006, 10:06 PM
Join Date: Feb 2003
There are five kinds of circuit protection.
1. Circuit Breakers/Fuses protect against short circuit and excessive circuit i.e. hair dryer and microwave. This keeps the wires from melting and starting fires.
2. Arc fault circuit interrupt: protects against arcing. Arcs may not be excessive, like a spark, but can still cause fires. AFCI is usually incorporated with the circuit breaker, esp on new homes.
3. Ground Fault Circuit Interrupt. GFCI: Protects against electrocution by ensuring that the current entering an outlet is the same as the current leaving the outlet. If they are different, it means that the current is taking a different path than expected, like your arm. This is a ground fault, and the circuit trips. GFCI outlets are required in the kitchen, bathroom, and anywhere else water is present.
4. Surge protectors. Protects you appliances against power surges from the Energy co. Usually used with computers. Not really applicable to an aquarium, except that surge protectors come with these handy dandy outlet strips that you can plug lots of stuff into. Many power strips also include circuit breaker protection as well.
5. UPS Power backup. Protect against power droops/brownouts from the energy company. You can hook up a computer UPS to your aquarium to use during power outages, but wont last very long if you're lights are hooked up to it. Really good for saltwater/reefs, not totally necessary for planted tanks.
The only ones really useful in aquariums are GFCI and breaker protected power strips. I installed a GFCI outlet at the wall and have a power strip in my stand. UPS might be useful, but expensive. I've never really considered it before.
I've never seen GFCI that stays off when power goes out. You can't run power tools off of GFCI because the outlet can't compensate for large motors. Plug your refrigerator into an GFCI outlet and see what happens when the compressor turns on. THe GFCI will trip almost every time. For this reason, there is a specific exemption for GFCI on large appliances, like refrigerators, dishwashers, and garbage disposals. Many power outages are accompanied by a surge or brownout, which is why surge protectors often trip on power outage. Artemis' point about failing in the off position makes sense, but I haven't seen that behavior in practice. I've never had to reset the GFCI in my kitchen after a power failure.