New GFCI outlet not working in circuit

Question

I have an outlet in my garage that is not GFCI. It has both line and load lines attached along with a ground wire. It works fine but when I plug in a tester and push the Test button, nothing happens (it should be part of a GFCI circuit so the fact that nothing happens means something appears to be wrong). So, I want to change this for a GFCI outlet. I installed the GFCI outlet and when I plug in the tester is shows "> 30 VAC" and "Open Gnd Neu" and the red light on the tester illuminates. I removed the outlet, reinstalled the old one and it works fine, except it doesn't respond to the GFCI test.

The reason I am replacing the outlet is because the inspector for our house said that the garage plugs should be on a GFCI circuit. I'm not sure why this particular outlet is not part of a GFCI circuit, but installing a GFCI outlet is not working.

Has anyone experienced this and/or knows why the new new GFCI outlet is failing? I tried two different new outlets and both produced the same error.

Thanks!

Answer 1

Those 3-light testers are infamously wrong, and only mislead novices. I call them "Magic 8-ball" testers. In fairness they are intended/tuned for wiring mistakes in brand new constructions, not troubleshooting in old work. However, when they add a battery and a computer, they get much worse, because now they hide the 3 useful lights and give you only the not-even-wrong meanings.

By that thing's indication, both the neutral and ground wires are broken, and clearly not if the outlet works. Say, when you claim it works, did you actually power an appliance off it? Or just get a hot light with a non-contact tester? Because electricity flows in loops. The hot wire is the diva, but neutral is just as important.

Anyway, I do not like the term "Line" and "Load" being used as synonyms for "the supply wires" and "the onward wires to other loads". And the reason is this: GFCI "Load" actually confers GFCI protection to the rest of the circuit. You may not want that. Always protecting the onward side of the circuit ignorantly as a blind habit, is a terrible idea that causes no end of woe and misery - we get it in this forum every week. You should be making a conscious decision: "Those onward wires. Do I want to GFCI-protect them here?" *And if you do, you must affix "GFCI Protected" labels.

For instance, this outlet may already be GFCI-protected from another GFCI elsewhere and they violated Code by not labeling them "GFCI Protected".

However, if you're not planning to GFCI-protect the rest of the circuit then do not use LOAD. See why I don't like calling the onward wires "Load"? There is nothing wrong with putting both wires on LINE on every single GFCI in your house, and then, putting a GFCI receptacle at every receptacle that needs protection. Honestly 90% of people think it works that way anyway. Read the instructions and they will tell you how to attach 2 wires to the LINE screw. Leave the warning tape on LOAD.

Answer 2

You've probably confused Line and Load, because that's the usual problem people have putting these in. A regular receptacle has no "line" or "load" - the terminals are just terminals.

Line (on the GFCI, where it's actually different) goes to the cable that is live when the outlet is removed.

Load (if used) goes to the cable that is dead with the outlet removed. Or you can connect both cables to Line, and nothing to Load, but that will mean there's no protection to whatever is downstream of the outlet (perhaps another garage receptacle that also should be protected.)

If you decide one cable is Line and the other is Load without actually testing them, you'll get it wrong 50% of the time, on average.