6-20r to 6-50p adapter wiring?

i'll leave this one to our registered electrician, jerry.

 

Nope.

 

NEMA connector - Wikipedia

 

It arguably doesn't matter much, if you're only building one, and only you will use it, and only where nothing nearby is fed from another one.

But another simple answer would be "yeah, just follow the diagram, horizontal to wide, T-shaped to narrow." Then there are no if-onlys.

-Chap

 

It doesn't ever matter at all. If you reverse the two wires of 240VAC, you still get 240VAC. The two sine waves are just inversions of each other (which is the same as a 180° phase shift). The only thing I can think of when this might matter is if you have two different circuits that need to be in phase with each other (think: motors), or multiple power feeds to the same equipment, neither of which applies here.

The reason it matters on a 120VAC circuit (in the US) is that one of the legs (Neutral) is a center tap from the transformer that gets earth grounded.

 

... so, if you were to combine your first, overgeneralized statement with your second, more reflective one, you might end up saying something like it doesn't matter much if you're only building one to be used in isolation from any nearby stuff fed from another one. Which is all true enough in this case, as you also noted.

On the other hand, it isn't any harder to follow the diagram, and build one that doesn't need any of those caveats, and that's the approach I think I'd recommend. To say it doesn't ever matter at all could be a disservice to future readers who skim this thread without thinking closely about when it does or doesn't and why.

-Chap

 

Point taken. But given that receptacles (in the wall), which would be used in this case, are wired with no phase relationship to each other, an adapter that keeps the phase (hot) wires straight vs. crossing them effectively makes no difference (since two receptacles might be reversed of each other anyway).

 

Generally, wiring intended for that application will still use two distinguishable colors (black and red, for example, not white, since neither one is grounded), exactly so your "two receptacles might be reversed of each other anyway" situation can be avoided.

Of course, assuming it has been avoided means trusting that the previous electricians on the project avoided it. And if you're one of them, that means someone, in the future, may trust that you avoided it.

And yes, old electricians will tell you they didn't get old by just trusting all past work was done right. But it is honorable to avoid being that person whose past work proves the point.

-Chap

 

Sure, but there's no standard for which terminals the red and black wires go to. Would an electrician adding a NEMA 6 (or 10, or 14...) outlet in a building open up other outlets in the facility to check how they were done, just so they could do it the same way? I'm gonna go with no.