Timer tripping my GFCI

[rroselavy]

Hey all-

My Hamilton timer, which only controls my 72W PC lights on my FOWLR Nano, has tripped my GFCI 2-3 times since I installed the outlet. Twice it happened when I switched the timer on manually, but once I arrived home to discover the GFCI had tripped. I am assuming that the timer was the culprit in this case as well, since there was no presence of water anywhere near the electrical.

This leads me the following questions:

1) Although I have a UPS that will drive my main pump when the power is cut, how long will fish be able to survive without circulation?

2) Has anyone else had problems with their timers causing false-tripping?

3) Does anyone have recommendation for another model/brand of timer that does not cause a surge/spike.

Thanks!

[wwest]

Have you tested the outlet with something esle? Try to plug in a lamp or a hair dryer and see if it will trip. Its possible the new outlet is tripping itself..

The timer will create a surg but i dont think enuff to trip the outlet that is why i would start at the outlet itself since its new.

[CarmieJo]

Alternatively, does the timer trip any other GFI outlets?

[rroselavy]

Have you tested the outlet with something esle? Try to plug in a lamp or a hair dryer and see if it will trip. Its possible the new outlet is tripping itself..

The timer will create a surg but i dont think enuff to trip the outlet that is why i would start at the outlet itself since its new.

Thanks much for the reply.

I tried our hair dryer, and it did not trip during many attempts. However, FWIW, the hair dryer itself seems to have a circut breaker of sorts built into the cord. I also have had a lamp plugged into the GFCI since I installed it, and have never tripped the GFCI while turning on the lamp.

The GFCI has tripped only a total of 3 times in the past month since I installed it, and only once unattended.

Previously I had a plug-in GFCI, which tripped almost EVERY time I manually turned on the lights from the timer. This is why I suspect it is the timer or perhaps my ballast.

I have a related question:

The rest of my equipment (except for the lighting timer and UPS pump) is plugged into a surge protector which is plugged into the second GFCI socket. Is it a bad idea to have a surge protector plugged into a GFCI? Will the surge protector prevent the GFCI from tripping when it should?

[rroselavy]

Alternatively, does the timer trip any other GFI outlets?

Thanks for the suggestion Carmie,

I will try this as soon as I can.

-Scott

[NaClFinatic]

I read somewhere that some UPS can trip a GFCI also. So take caution on that route also. And if an UPS provides continous power, why have a GFCI when it trips the UPS will power off battery?

[wildeone]

I read somewhere that some UPS can trip a GFCI also. So take caution on that route also. And if an UPS provides continous power, why have a GFCI when it trips the UPS will power off battery?

Not sure I am following your question here...

Are you asking why have GFCI when you have a UPS?

Or

Why have a GFCI if when it trips it shuts down the battery?

Or

None of the above?

GFCI's are a litle finicky, but I would be surprised if an inrush of current was causing your issue. A Hair dryer, toaster oven, microwave etc. all pull tons of current during an inrush at startup, so I think that a MH would be no big deal to a GFCI. Is the MH going right into the GFCI or in a strip? Are you sure there is no water (not eve a single drip) going into the outlet? I know that mine is going into a strip and if I drip one drop of water on the strip I pop it.

I have not had much luck with timers as far as reliablilty. I cannot recommend a mechanical timer that works well.

[wwest]

I use outdoor timers, They are water proof and most have a protected cover on the front to cover it up from water. I have had great success with the ones i have right now. Maybe try that route..

[CarmieJo]

I bought a 2 pack of cheap mechanical GE timers and they have worked flawlessly. I did have a problem with a fancy digital model.

[wwest]

I HATE DIGITAL!! Sorry just a touchy subject. lol I bought 3 digital timers and where i am from power spikes are,..well more common than ladybugs. Well everyday i had to do something to at least one of them. The package says battery backup for power outages and power spikes. Well mine didn't work. So i would stray away from digital timers.. :)

[wildeone]

I bought two mech timers (different brands) and both of them failed on me in the same way. The little pins that you use to set the times wear out and then they don't hit the switch, so whatever mode it is in it stays in.

[NaClFinatic]

Not sure I am following your question here...

Are you asking why have GFCI when you have a UPS?

Or

Why have a GFCI if when it trips it shuts down the battery?

Or

None of the above?

Actually I meant that if you plug an UPS into a GFCI, when the GFCI trips, the UPS battery kicks in and continues to supply power. The UPS should have a breaker as well but is it as good as a GFCI to keep you from getting shocked?

[wildeone]

Not as good. Here is what I know. In any electric, you have a hot, neutral and maybe a ground wire. Current flows from Hot through your appliance and returns on the neutral wire. The current (or amperage) on the neutral and on the hot should be the same when you are running the appliance, say a hair dryer.

Lets say you are taking a bath and drying your hair (real dumb), and you driop the dryer. With just a fuse, the amount of current will increase because the current is now flowing from the hot, to the water and throught the piping and to ground. The current increases and once it reaches a high enough level (labeled on the fuse in AMPS) the fuse blows by disentigating a copper wire inside that is sies to burn through at that amperage. With a circuit breaker, it actually creates a magnetic field that pulls the trip lever inside the breaker. As the current rises the magnetic field increases, thus pulling the lever and breaking the circuit. In both of these cases, you would more than likely be electrcuted before the breaker or fuse blows.

The GFCI actually measures the current on the hot and the returning current on the neutral. Within a second of seeing a reading that has more current on hot than on neutral the GFCI trips. So when the current from hot goes into the tub, to the piping and to a ground, it increases and the neutral stays the same. The GFCI is very sensitive, sometimes tripping on as little as a 5000th of an amp difference, and much faster than a fuse or breaker.

[NaClFinatic]

Great explanation duane!

Personally I plan to split up my equipment on two separate GFCI outlets. The return pump can be on one and the powerheads on the other. Then if one trips there is still circulation in the tank.

[rroselavy]

Alternatively, does the timer trip any other GFI outlets?

I have finally determined that my digital timer was the culprit. After another few weeks of normal behavior, I returned home one evening to find the GFCI tripped. I checked to make sure all of my electrical plugs were dry, reset the GFCI and turned my timer on manually. The GFCI tripped again instantly - and again - and again. I then unplugged my lights from the timer, inspected the timer for moisture/residue/foreign object. Dry and clean as new. I then unplugged the timer and plugged my lights directly to the GFCI. The GFCI would not trip whenever I turned on/off the lights. I inserted the timer once more to double check, and the GFCI went back to tripping instantly.

I have since purcased a digital outdoor timer made by Sylvania at Target for $20. It is more water resistant, can easily be mounted on a wall, has three sockets (including one untimed socket) a bigger, illumiinated buttons/lcd panel, and hasn't yet tripped my GFCI. ;-)

Thank for all the help guys, and beware of tripping timers!