Plugs and sockets come in so many shapes and sizes with various ratings and host of international and local standards that I often feel like learning Klingon might be easier. Our engineer, Jon, assured me that it really isn’t that difficult. I was suspicious, so he put together a cheat sheet in “english!” (as I often let to tell our engineers and techs). I’ll admit it – he succeeded with flying colors:
Plug Configuration Cheat Sheet
Most of the power plug types you will encounter will conform to either NEMA or IEC standards. IEC plugs and sockets generally connect directly to electronic appliances such as desktop computers, laptops/charges, kettles, etc. NEMA plugs and sockets plug directly into wall outlets.
In other words, if you are plugging a cord into an appliance, it will most likely be accepting a IEC socketed cord. If you are plugging a cord into a wall, it will be a NEMA socketed cord. A single cord can have a NEMA plug at one end and an IEC socket at the other end (this is completely normal and it is common on all desktop computer power cords).
A UPS is not considered an “appliance” by this definition and its cord and output sockets are both NEMA
What’s are the major differences between power plugs?
Straight blade plugs VS Twist-Lock plugs.
Plugs inserted into a receptacle with a single linear motion are usually Straight-Blade plugs. Those which can slide into a receptacle and then rotate by a few degrees fall into the Twist-Locking family. These create a far more reliable connection because the twisting action locks the plug in place, prohibiting the plug from disconnecting from the socket.
Maximum operating Current rating
Plugs will generally fall into one of these current rating ranges: 10A, 15A, 20A, 30A, 50A or 60A
Maximum operating Voltage rating
Plugs will be rated at one of the following operational voltages: 115V, 125V, 250V, 277V, 480V, 600V
Keep in mind:
The maximum operating voltage rating on the plug isn’t necessarily representative of the actual operating voltage of your equipment. For example, a UPS which is rated to operate on 208V may use a 250V plug. As you can see in the table below, there are multiple applications for each plug.