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We are still working some of the kinks out of our new house. One thing that has been driving me nuts is an outlet in the basement. Its one of those with the circuit breaker built into it.

About a week and a half ago, it started blowing for no apparent reason. At first I thought it was overloaded, but now I only have a computer and the cable/internet box plugged into it.

The other weird thing is that it always blows between 6 and 6:30 am. No other time. I have a sneaking suspicion that our cable/internet provider is pushing an update at that time which is causing the box to go crazy.

At this point, I'm going to unplug the computer from there and see if the cable box makes it blow. Thoughts?

There might be something on a timer that's causing the problem..

Are you comfortable with taking the outlet ( GFCI ) out of the electrical box?

I'd just replace the GFI outlet with a regular outlet and use a UPS type supply.

Spazmogen wrote:I'd just replace the GFI outlet with a regular outlet and use a UPS type supply.

Have done that before, but without knowing what the GFCI is protecting further down the line it's a tough call. Would hate to see someone get fried.

Spazmogen wrote:I'd just replace the GFI outlet with a regular outlet and use a UPS type supply.

The computer on there is plugged into a UPS. It's the only thing that saves it from crashing every mornning.

I don't have anything set on a timer. However, I'm not sure about the cable company. They might be trying to update the box in the morning.

There might be something in the house equipment that you're not aware of..

I wouldn't suspect that the cable box is tripping the GFCI. If it was the cable box it would almost certainly trip the GFCI as soon as you plugged it into the GFCI.


I already started typing the following up earlier. If your interested, it will explain what the GFCI does and walk you through process of narrowing down the source of the problem.


I don't know how much experience you ( or others ) have with wiring or GFCI outlets so here is a quick overview.

1) Circuit breakers are designed to protect the building from fire, over current / over heating. They only measure the demand on the hot wire.

2) GFCIs protect people from electrocution. By measuring the power on both the hot and neutral wires a GFCI can react to smaller variances in power and also respond more quickly. Generally, if there is a variation of 5 milliamps or more between the hot and neutral wires the GFCI trips. The advantage is that if you happen to be grounded and touch a hot wire or hot enclosure etc but only draw, for example, 18 amps on a 20 amp circuit the GFCI would trip but the circuit breaker wouldn't because the circuit hasn't gone above a demand of 20 amps.

3) Usually, but not always, the electrician will run a circuit from the main panel box directly to the GFCI. The wires from that circuit connect to the " line side" terminals on the GFCI. Anything that plugs directly to that GFCI will be protected.

Also on the GFCI are two more terminals "the load side" . If the electrician used that same GFCI to protect additional standard type duplex outlets or equipment (very likely because its cheaper) something further down the circuit could be tripping the GFCI. Maybe a automatic sprinkler, central air humidifier, pump at a fish pond, hot water circulator pump etc..

With that in mind, if you want to try isolating the problem, turn the power off at the panel box, remove the two screws that mount the GFCI to the outlet box. Do you see three or five wires connected to the five terminal screws on the GFCI? If you see five, I would disconnect the two on the load side ( its labeled ), reinstall the GFCI in the box and plug everything back in like it was when it tripped. If it doesn't trip over the next couple of days then something else further down the line ( load side) is causing the problem. If it does trip, either the GFCI is faulty ( unlikely because of what you described above ) or whatever is plugged into that GFCI is letting power trickle to ground instead of the neutral.

If you see only three wires on the GFCI when you initially take a look at the GFCI then the problem is a defective GFCI or one of the items that your plugging directly in to the GFCI.


BTW, if the GFCI did have five wires on it and you removed the two on the load side you killed the rest of the outlets on that circuit. Make sure that we didn't take out a refrig, dialysis machine or something else that's important.

Hmm.. I'll have to check the water softener to see if its scheduled for 6am. Thanks for the info!

You're welcome.

I should have mentioned yesterday, even though it's cooling season I wouldn't rule out a humidifier ( if you have one ) because recent practice is to set those up to purge daily. The intent being that it lessens the chance of fungal growth in the duct work.

If you get a chance, let me know what the source of problem is when you get it all figured out.

We have a dehumidifier but that runs 24/7. It's plugged into another outlet and doesn't seem to be affected when the GFCI blows

did you sort it out yet?

Yes and no. I moved the computer over to another outlet and the GFCI hasn't blown. I still haven't figured out if it was the computer that was causing it to blow or its something else. By moving it, I think the load is just lower now.