115vac fan, 2 conductor wiring> help please!

[working on it]

First of all, I'm not an electrician, but am experienced with automotive 12vdc, and not with household 115vac wiring (ask the wife). I'm about to install a 115vac duct fan in my trailers A/C ducting. A really nice product. However, the 2 wires aren't identified as positive or negative. Both are black, but one has white printing along it. Again, I'm a 12vdc guy, not 100% sure of the AC color coding (and anyway, I even see 12vdc products with the wires colored wrong all the time, so I am suspicious of all wiring...recently my 12vdc LED license plate light wiring was reversed). I presume the white printing means white-negative , and the black is black-positive. And if I get it wrong, the fan should run backwards, to no harm. But, the fan has a one-shot internal fuse, and I don't know if it might blow in that circumstance. I cannot contact the maker today, on Sunday, and I want to forge ahead. Can any of you 115vac wiring wizards give me a hand here? Thanks.

[Dale M.]

IF a AC circuit (as in Alternating Current), "unit" has 2 two black wires (only) its not critical to how its wired (polarity) .. Put "white" wire (neutral) on one wire and "black" (generally hot) to other,,,,

AC circuit (120volt) with two same color leads are not generally sensitive to polarity and are generally isolated (internally) from any other electrical connection (grounds) ...

Dale

[working on it]

So if it is not sensitive to polarity, then the " one-shot" fuse is just thermal protection and won't blow in just a run test? I'll hook it up in a few minutes to test direction, then connect permanently and ad a switch. I had to re-configure the ducting somewhat; that bought me time for your response. Thank you.

[rowerwet]

according to the wiring book I got from HD when I rewired my house, the printed wire would be connected to the black wire, but it really wouldn't matter that much like the other poster said. AC current goes both ways, there is a diode "bridge" inside the motor that makes sure all the power goes the same way through the motor.

[working on it]

My eyes aren't what they used to be...when I took it outside into the sunlight, and used a magnifier in that light, I saw that both wires had printing, though one was really faint. Because Dale M. reassured me that no harm was likely to happen to it, I connected them to a test plug, and it ran fine, in the correct direction. Not taking any chances, I didn't test it the other way. I ran the wires thru the wall, plugged it in, turned the A/C on, and all was good. Thanks .

[Rolly]

I can not point to a book or manual but I believe the smooth wire is hot and the ribbed wire is neutral on zip cord.

Rolly

[working on it]

My eyes aren't what they used to be...when I took it outside into the sunlight, and used a magnifier in that light, I saw that both wires had printing, though one was really faint. Because Dale M. reassured me that no harm was likely to happen to it, I connected them to a test plug, and it ran fine, in the correct direction. Not taking any chances, I didn't test it the other way. I ran the wires thru the wall, plugged it in, turned the A/C on, and all was good. Thanks .

Rolly-Thanks for your reply, but as you can see, its already done (I just didn't want to blow the irreplaceable fuse).