I’ll be doing an addition to a cabin, the foundation for which will require removal of the underground electric supply. The cabin is fully wired with it’s own subpanel. Potential load includes small refrigerator, microwave, hot plate, ceiling fan, typical lights. During the construction phase, I can eliminate use of the heavier loads by pulling the breakers to those circuits, but would still like to have switched lights and be able to use the two outside recepticles for power tools.
I have another source of electricity (workshop 70 feet away) with 20 amp exterior GFCI outlet. Is there anything wrong with running a 12 gauge extension cord that distance, and energizing the cabin subpanel with a male/male adaptor that would run from the end of the extension cord to one of the outside recepticles?
I realize this would be feeding the cabin with just one 20 amp circuit and will make the appropriate decisions regarding loads, and the cable currently feeding the sub panel will be removed entirely from the lugs and disconnected from it’s distribution panel lugs….just wondering if there are any other gotcha’s that I haven’t considered associated with energizing a subpanel via one of it’s outlets. Would the term “back feeding” be appropriate?
TIA
Replies
You have two problems.
First I using a male adapter is a damagerous idea. You will have a hot male connector.
The 2nd problem is to that this will only energize one leg of the 240v.
Here is a much better way of doing this. Go to the sub-pannel and connect a cordset with a male end to where the feeder cable hooks up and install a jumper to feed both legs.
Then plug the male end into your extension cord.
Ah ha. I see I was only about 50% there or worse (with the hot male)
Should the ground in this cordset also be connected to the EGC bus in the cabin subpanel such that the ground rod back up at the workshop acts as the EGC for the cabin, as the cabin subpanel ground rod will also be removed?
Is it acceptable for temporary use to make up my cord set from regular NM 12-2WG? I have one left over from a temp pigtail lite.
Thanks for your help and advice.
"Should the ground in this cordset also be connected to the EGC bus in the cabin subpanel such that the ground rod back up at the workshop acts as the EGC for the cabin, as the cabin subpanel ground rod will also be removed?"
Yes, really thing about it his way. The sub-pannel is just acting like a gaint multi-tap end. So you want to carry through all of the connections.
"Is it acceptable for temporary use to make up my cord set from regular NM 12-2WG"
Not really. It will be exposed to the sun and probably get run over, at least by wheel barrows.
Buy a 100 extension cord, it is cheaper than buying bulk cordage.
Thanks again, Bill.
Actually I already have the extension cord, it's just the short piece from the panel lugs to the male end that will plug into the extension cord that I want to make up out of romex. It will just stick out of the wall a bit, be stapled, and is on the north side, thus no sun. Expected life of this jury-rig is 1 1/2 months, until the foundation is up and the new wall framed and sheathed.
I probably will pick up another good 12 gauge cord though.