Polarized cord caps for devices

[torcho]

Okay, pardon my ignorance and I know I am going to probably catch hell for this but here goes..... Why do some of my appliances have polarized cords? I mean what gives. My ShopVac has one, my George Forman has one, but my rice cooker doesn't, my cell phone charger doesn't, nor do a few drills I have... I am a little confused. It's not like my resistive loads will function any differently. What is the design issue behind this? It's not like my air compressor will turn into a vacuum if I flip the cord around...it is AC after all. I understand that potential was designed to be introduced into certain parts of a circuit, but why would it matter on my George Forman? It doesn't have any external controls, nor does my waffle maker, but they are polarized.... Just curious...don't shoot the messenger please.

 

[hurk27]

Not sure on double insulated motor appliances as I don't see the need unless there is metal that a person can touch that could be energized if the motor went to ground, but then you would think it would require an EGC?

Transformers like the wall warts are isolating so I can see them not having a polarized plug.

But as for heating appliances I have always thought it was encase the heating element faulted to the case, but thinking about it longer, a heating element can fail at either end so a polarized cord doesn't always protect from this, remembering as a kid getting shock from a toaster we would just flip the plug over to remove it, and since there is no EGC it would just keep on toasting.

Lamps probably makes the most sense to me for a polarized cord, it is about one of the only few loads that need to keep the lamp shell on the neutral, the rest, I have no idea, well not right now as my brain is not thinking too well.:roll: