We are talking about garage and outdoor receptacles. These are both required to be GFCI protected. It is extremely easy to trip a GFI if you are working on the circuit live. Simply touching the neutral to ground, or even testing from hot to ground can trip them.
You have a tripped GFI somewhere, you need to find it. Could be nearly anywhere; garage, somewhere outside, near the main electrical panel, etc.
Let us know what you find.
I've come across a scenario in which this feature might actually improve safety:
Some older European buildings still have TN-C wiring in place. Current wiring codes no longer allow this due to safety concerns (which I'll get to in a minute), but there is no requirement to upgrade as long as no modifications are made (simple replacements, such as installing a new switch in place of a faulty one, do not count as modifications).
With TN-C there are two wires from the main panel to the wall outlets: a live wire and a combined ground-neutral (PEN) wire. At each outlet, there is a short length of wire bridging the ground and neutral terminals, and the PEN wire is attached to one of these two terminals.
However, an interruption in the PEN wire presents a safety hazard: devices are still powered via the live wire but the circuit is interrupted due to the faulty PEN wire. Touching the metal chassis of any device on that circuit will have the same effect as touching the neutral wire: doing so while grounded will turn you into the missing link in the PEN wire, which can be deadly.
This was the reason for phasing out this practice in favor of TN-C-S, which splits up the PEN into two wires at the distribution panel. With TN-C-S, interruption of a single wire affects either the ground wire or only the neutral wire, neither of which present an immediate risk of electric shock in an otherwise compliant setup.
Enter the GFI outlet: if used to replace a regular outlet in a TN-C setup, the PEN gets interrupted and someone were to touch the metal chassis of a device plugged into the GFI outlet, the GFI would trip. At the most, you'd feel a slight, short tingle as you touch the device.
Since a faulty PEN is likely to cause a brownout or blackout, having the GFI trip on low voltage would likely cause it to trip on a PEN interruption. Devices plugged into the outlet would not be hazardous to touch (and not even give you a tingle as you did), although devices not behind a GFI would obviously not benefit from this and still present a hazard. Additionally, a tripping GFI may alert people that something may be amiss – another example why a circuit breaker or GFI tripping should not just be considered a nuisance to be fixed by switching the power back on, but as an indication of a potential hazard that needs to be looked into.
Best Answer
Yo Dawg
Who was the electrician? Xzibit???
Because putting a GFCI in another GFCI's protected zone is rather silly.
Speaking of silly...
Refrigerators and GFCIs
You want a refrigerator to last a long time, so they want to hermetically seal the Freon stages so the Freon doesn't leak out. But how do you seal the piston rings of a compressor? By putting the whole compressor inside the freon tank. But then, how do you seal the shaft of the motor? By putting the entire motor inside there too. So you have a steel jacketed motor swimming in Freon inside an aluminum tank, stuffed in the bottom back of a fridge that's entirely wrapped in steel and grounded. You have no chance of touching the Freon tank, let alone the motor, and you're not likely to drop it in the sink. Does this sound like the use-case for GFCI? No. No it does not.
Now, an AC induction motor is (as you might guess) a very big inductive load. Inductors, when disconnected, must continue to flow current, and will increase voltage to infinity until they do. This plays badly with GFCIs, as you might imagine.
This is the classic "safety system versus safety system" scenario, like a low-oil-level trip on a fire pump: saves the $50,000 engine and lets the $50,000,000 warehouse burn down. The well-meaning GFCI poisons all your food. If the trip isn't noticed by the right people, someone might just reset it and no one's the wiser.
This is a big problem that is well known to the industry.
GFCI does not belong here. The Fridge should be removed from GFCIs entirely. In many common freezer locations, this isn't quite legal because of a general Code requirement to have GFCI on receptacles in those rooms. So this will require a nudge and a wink from the local inspector; or; he doesn't need to know about it.
So change the duplex GFCI receptacle for a simplex plain receptacle, and label it "Dedicated for freezer". That is making a fair effort to assure the receptacle isn't used for anything else, and that will satisfy many inspectors, who perfectly well know the problem of refrigerator GFCI trips.
You should now have a surplus GFCI receptacle and breaker. What to do with those? Find another circuit that does not currently have GFCI protection, but could use it.
By the way, do the same thing in your kitchen. De-GFCI your fridge.