KW Power cord

[RGL333]

i have just received a new power cord for my KW (still my main power supply since 1955). I mmeadiately noticed one blade is wider than the other. Which side does the wide blade go to? Does it matter? Thank you.

[arkady]

I'm not an electrician, so this is based on my personal experience.  But I don't think it matters.  My KW has a non-polarized plug, and I've never paid the slightest attention to its orientation when I plug it in.

[Trucktrain7]

It doesn't matter as long as you don't want to phase your transformers together. If you think you may want to, then the wide blade should be attached to the same feed as it goes out to your A&B post (on the same side of the coil). But if your just replacing it because you want an updated better cord then it don't matter. I replaced 2 of mine but with the reproduction "L" style on the plug and those are not polarized. In the case of phasing the transformers like that you just flip the cord around if its not correct phase.

[BigAl 956]

It only matters if you are phasing transformers. To get it the same as the old look very carefully at the old cord. One of the leads should have a rib running with it. That is the wide blade/neutral line.

[lionelsoni]

Even if the original cords were marked (with the rib), I would not be surprised if Lionel ignored the polarity in assembly, since, as others have said, it mattered not at all from their point of view.  My practice in using modern polarized plugs is to match the polarity of the plug to the polarity of the output voltage, with the grounded primary blade corresponding to the secondary's common terminal.

[RGL333]

BigAl 956

It only matters if you are phasing transformers. To get it the same as the old look very carefully at the old cord. One of the leads should have a rib running with it. That is the wide blade/neutral line.

Thank you! 59 years and i never noticed! It's true- you learn something new every day. Thank you

[BigAl 956]

I learned this back in the early 1970's when I was in High School having never noticed until my shop teacher pointed it out to us. The rib to neutral practice is a post-world war II standard. Polarized cords came about later in the 60's. So while it may not have been necessary to pay attention to the polarity of the cord at the time, transformer phasing was a documented procedure with Lionel so it was in their best interest to solder all the line cords the same way.

When I replace a line cord today I always phase to another transformer first and then use a modern polarized cord to match so my transformers are easily phased in the future should I need to unplug them.

In this case just match the rib connection to the old and you will have wired it as the original weather it mattered to the factory or not.

[lionelsoni]

I agree that it is useful to have a standard; but I don't trust Lionel to have followed one.  That is why I follow my own standard (which I think has a certain intuitive quality to it:  secondary in-phase with primary).  But, in any case, although it helps, just having polarized plugs wired consistently doesn't guarantee that transformers will be in phase.  A not-uncommon house-wiring method, the "three-wire circuit" always results in a duplex receptacle's two sockets' being out of phase.  In this case polarizing the plugs the same always defeats the purpose.  A similar effect can result about half the time when transformers are plugged into outlets fed by different circuit breakers.  A good way to avoid these pitfalls is to combine consistent plug polarization with powering all transformers through a single power strip.