How to Reconnect an Old Thirty Amp, 240 Volt Plug

Our water well is powered at need by a portable generator. Lug the gennie over to the wellhead, stuff the four-prong, 30 amp plug into the 240 volt receptacle, and things are good to go. How to do that when the generator refused to run for nine months, though, was another matter.

Turned out we had a friend in need who was a friend indeed. Robert brought his family's big diesel generator over every time we needed to fill the 500 gallon batch sorage tank for nine long months.

The only thing was, his unit didn't have an outlet to fit the plug at the end of the well cord. In the end, we had to remove our plug and hardwire the thing.

Today, it was time to reverse the process, what with our Troy-Bilt generator finally up and running and the water tank needing a fill. The old plug was stashed in the Subaru's center console storage bin. I dug it out...washed it out, since it was caked with red dirt. There was a question in my mind, however.

How was I going to be absolutely certain I hooked the thing up right? It has four receptacles for as many 8-gauge wires. Get any of those wires out of place, and the results would not be pretty.

I thought I knew...but did I really?

In the end, a bit of online research and a discovery about the plug itself made all the doubts go away. To wit:

1. The green ground wire must go in the right spot, but the plug itself was labeled "GRDG" at that point--which I chose to believe meant "Ground, Green". Besides, there was a green screw head visible through the plastic that promised, "Yeah, you got it right, buddy. Go for it."

2. An eHow article explained that the "Y" and "X" wires/receptacles were for the red and black wires...and that (most importantly) it didn't matter which side was hooked up to which.

3. The same article also clarified something crucial: The white wire (which in our well cable's color coding is actually yellow) "splits" the 240 volt current. Measure between red and black, you get 240 volts. But measure between either white/yellow and red or black...and you get 120 volts.

4. The receptacle tunnels on the plug itself were actually labeled: G, Y, X, W.

We were good to go.

The next step--several steps, actually--involved getting the wire ready for reinsertion into the slots. This was no small thing, as all four wire ends looked pretty crappy. That is, blackened from corrosion and even (in the case of the yellow wire, for whatever reason) burning.

This process went as follows:

1. Using side cutters (as we called them when I was growing up in Montana), snip the wires a bit shorter than they were. Not a problem here, as there's more than enough extra cable length available.

2. With some careful cutting (knife) and prying (pliers), slit and peel back the heavy rubber outer sheathing to expose the right amount of current-carrying wire. How much is the right amount? Far enough to get the wires into the plug without later exposing them to the elements. I had to experiment a bit with this.

3. Use a wire stripper to clear about an inch of insulation from each wire. Except that an inch turned out to be too much, and the amount of exposed copper had to be nipped off another quarter inch or so to get it right.

4. Insert the wires into the plug (following the color coding) and cinch down the side-mounted retaining screws that tighten internal clamps on the various wires.

Now for the weatherproofing, yank-proofing sleeve which had been left on the cable to gather dirt, cobwebs, and what looked like part of a mouse nest during the seasons. After a bit of picking and cleaning, the sleeve is brought back up over the rear of the plug and screwed down tight.

This involves (for this particular part on this particular plug) two screws that attach the plug to the sleeve and a separate pair that cinch the collar at the rear of the sleeve down tight around the cable sheathing.

Mission accomplished; the old 30 amp plug is now reconnected to the well cable safely and correctly.

Naturallly, it's necessary to pick up the tools and the trash.

But...does it work?

Only one way to find out. The Troy-Bilt generator is pulled (by hand, thank you) from the Border Fort over to the well site. the plug is inserted into the proper outlet, the beast is fired up and...yes! Water pumping through the half mile of PVC piping, pushing water into the batch storage tank as it was designed to do. Good thing, too; the tank was almost empty.

Field test, the only way to go.

Finally, to round out this "How To" Hub, a couple of bonus photos: A shot of morning gold and a little bird on a truck tire.