Small Component Ratings on Cable and Power Cords, Challenger, and Basic Catastrophe Prevention

In the electrical world there are two main types of disasters—those caused by nature, such as lightning, and those caused by humanity’s occasional and fateful interaction with power lines and high-voltage equipment (AC power). However, there are electrical hazards caused by small components that may fly under the radar when documenting electrical safety protocols.

While smaller components contained in a power cord or cord set may look diminutive, they can still pack a powerful enough punch to cause equipment damage or fire hazards, especially when placed in direct contact with current. If used incorrectly or of faulty design, they can cause catastrophic outcomes for humans and their surrounding structures.

IEC 60320 Appliance & Interconnection Couplers:

This chart illustrates IEC 60320 connectors, inlets, plug connectors, and outlets in their different families. Example: IEC 60320 C13 connector and C14 inlet are in the Class I, Cold family, along with the IEC 60320 Sheet E plug connector and Sheet F outlet. The IEC 60320 C15 connector and the C16 inlet are in the Class I, Hot family.

Cord-related Components

A good way to avoid an electrical catastrophe is to first know the electrical ratings of the components being used. Take the humble wire nut (metal inserts often containing coiled wire that are housed in small cone-shaped plastic sheathing for twisting wires together). The current rating of the wire nuts, or crimped ferrules, ring terminals, spade terminals, and quick disconnects are determined by the rating of the AWG or mm² cable. The rating is based on current only, for example, 14 AWG cable is rated at 18A. Therefore, the wire nut fitted to hold those wires together for 14 AWG cable will have that same rating of 18A.

Problems arise when trying to use a 14 AWG cable wire nut on 12 AWG cable, or worse, trying to fit a 16 AWG wire nut on a 12 AWG cable—it might fray or even cut the strands of wire. Also important is to never trim larger wires to fit smaller terminals, or allow the strands of wire to be pushed outward and become frayed. Trimming conductor wire is dangerous for multiple reasons, the main one being the same amount of current is pushing through fewer wires, which could potentially cause a heat issue. And with frayed wires, there’s always the looming specter of arcing which might start a fire.

Wire Nut Size Examples (Not Sold by Interpower)

When Components Fail the Unthinkable Happens

January 28, 2025, will mark the 39th anniversary of the horrific explosion of the space shuttle Challenger, which disintegrated 73 seconds after liftoff. The crew of seven perished: six astronauts, including the second American woman in space (Judith A. Resnik), and schoolteacher Christa McAuliffe. Seven heroes died that day because an O-ring on one of the solid rocket boosters failed to seal off highly pressurized gas. The leak became apparent shortly after liftoff as billowing smoke and bright flames were highly visible. Challenger continued to rise as if defiant, only to rip apart a few seconds later to the horror of millions. Still, the crew and its shuttle remain indelible on the psyche of those who watched it live or on tape.

How do small components in the electrical cable and power cord industry rise from inconsequential to consequential? Most cord sets can be checked at the outlets to visually ensure the plug is mated all the way into the socket, or if a plug connector is seated correctly into its inlet. Below is an example of how not to connect a plug into a socket.

A Real-world Plug & Socket Example

It may sound overkill or even paranoid, but routine checks of country-specific plugs or plug connectors connected to outlets are well worth the time. Cord manufactures have to meet stringent specifications concerning materials and diameters of plugs, blades, and pins, and the same goes for outlets and their components. However, someone in a hurry or with weak hands may not fully connect the plug and socket leaving a potentially dangerous gap. This gap could cause dust and debris to get inside the contacts, and also exposes the pins and blades which may be conducting current if seated deep enough into the outlet’s slots. Exposed blades and pins could also be bent or otherwise damaged from tools or other foreign objects.

A real-world example comes from a customer technical support specialist at a cord manufacturer. A customer had sent the manufacturer an e-mail containing photos showing a close-up of a plug pin that had been pitted and discolored on the tip of the pin. The photo also showed the outlet which had a melted slot where the pin had been inserted. So, what happened?

Arcing on Pin

After studying several photos accompanied by text, it was quickly determined that the pin was not fully engaged into its female contact or slots—in fact, it had barely touched the contact leaving the pin mostly exposed. The diagnosis? The pin had been subjected to arcing, which had pitted and discolored the tip of the pin barely touching the female contact. If the pin had entered a little further, i.e., seated just enough into the slots as to actually conduct current (leading to zero resistance), arcing would have ceased. Electrical arcs love firing across the microscopic imperfections of material. If this had happened in a combustible environment where metallic, plastic, or chemical dusts were present in substantial volumes, the combustion may have caused a devastating explosion. Better to have taken the time to check the connection.