Electrical line has no juice after being shortened

Question

I have a dedicated 15amp line running to my garbage disposal. The line did not run to an outlet, but was hard-wired straight to the disposal. I was installing an outlet under the sink so that I so I could plug in one of those little hot water tap water heaters. My plan was simply to cut the line and run the part coming from the panel to an outlet (GCFI) under the sink. I would then, inside the box, pigtail the wire and pick up the hardwire to the disposal as well.

When I completed this process, nothing worked. Not the outlet, not the disposal. The disposal had worked before. Now, when I test the line, the line from the panel is not live at all...nothing. I took the outlet off, and the line is still dead. The breaker doesn't seem to be loose, I've taken it out and put it back in. I actually even swapped it with another breaker I knew was working and it worked in the other spot on the panel while the working breaker wouldn't work in this spot.

I guess I'm just not sure how the line could go dead so easily. I've gone into the crawlspace and tested all the wires running through there that could be the right one, they are all live. This seems then like the disposal line somehow goes dead between the crawlspace and the actual spot it comes out under the sink. Is that possible, for a line to go dead at some point without shorting the whole thing?

Is there something I'm missing, or would I need to run a new line? Any help would be greatly appreciated?

Answer 1

Usually there is a switch before the disposal. You push a button, or flip a switch to turn on the disposal. Did you turn the switch on? If this is the case, then this was not the best option for this installation. As well as the undercounter heater may require a dedicated circuit.

Answer 2

If the line has indeed gone dead, it seems most likely that there is a junction somewhere between the crawlspace and where the line re-emerges. Hopefully you don't have a hidden junction somewhere or a buried splice. The reason I say this is that it's extremely unlikely that you could break the wire by pulling on it. If there is a break in continuity, it's probably because a splice came loose.

Since you know the breaker, cut it off and check the lines in the crawlspace again. You should be able to find the one that is now no longer live. One caveat: if you are using a EMF tester, and a lot of lines are close together, it may be difficult to determine that one is off. It's also possible to get induced currents.

Are you sure this circuit is dedicated? I once had a circuit go dead after a flooding situation and I thought the circuit was fried. After a really long time, I determined that a GFI outlet in another area of the house was on that circuit and had flipped. If you are in an older house, circuits can often route through surprisingly circuitous (no pun intended) paths.

Also one word of caution: if you are testing the voltage across the white and black and only the white (neutral) is disconnected, you will get no reading but the black is still hot. Connect a wire to a known good ground such as the ground in a three-prong extension cord into a grounded outlet and test the voltage from the black to that.

Answer 3

Check to make sure your wires aren't fried:

Disconnect everything at both ends. Tie black to ground at one end and check for continuity at the other. Do the same for white to ground.

If you don't get continuity in one of these scenarios, find the broken wire by swapping what's tied together... not that it would matter. If you don't get continuity in ANY of these circuits, you'll have to replace the entire length.

Note that none of this will work if you have shorted any wires, though if that was the case, you shouldn't be able to reset the breaker.