Difference Between Grounded Vs. Non-Grounded Plug Cords

Alt text – Difference between grounded Vs. non-grounded plug cords

A plug is a crucial element of the power cord that connects the power cord to the main electrical supply via a wall power outlet. Power cords usually have a plug at one end and a connector at the other that connects the outlet to an electrical device/machine.

All power plugs share specific characteristics, including that they transfer direct and altering current to the connector. However, they also have numerous differences influencing their compatibility with connector cords and various appliances.

Power cords can be grounded or non-grounded power cords. Read on to learn the difference between the two and why it matters.

What is grounding?

Alt text – nema 5-15r, 5-15p

Since grounding is the distinguishing characteristic between grounded and non-grounded plug cords, it is prudent to define grounding first. Grounding, or a grounding system, is a pathway that conducts excessive electrical current away from a device and into the ground to prevent electrical hazards.

The earth has electrical-conducting properties that carry the electricity, reducing potential risk. Therefore, grounding is a safety feature that helps prevent electricity-related injuries, deaths, and property damage.

Grounding/earthing in electrical engineering dates back to the early 1800s, thanks to Carl August Steinheil, a German scientist. Steinheil, a pioneer in telegraphy, discovered that the earth could function as a return path to complete a circuit.

In 1918, the US national electrical cord (NEC) declared that all buildings and transformers should have grounding unless otherwise authorized. Moreover, by 1971, NEC required grounded power outlets/ receptacles for all standard 120v outlets in all homes.

The grounded receptacle's development led to the ground prong's creation in grounding plugs, including NEMA-approved devices like the C 13 plug and the C 13 connector. However, non-grounded plugs are yet to be phased out; you can still find such plugs on the market, including the NEMA 1 and the NEMA 5 plugs.

Alt text – power cords, bulk wire

Grounded Plug Cords

A grounded plug’s distinguishing feature is three prongs, two parallel prongs, and one lone, centered prong. The two parallel prongs fit into the corresponding slots in a wall receptacle, the neutral and hot slots, while the third prong fits into the grounding slot.

Electricity flows from the hot slot into an electrical device and back via the neutral slot to complete an electric circuit. The main switch features an electrical plug connector where the hot and neutral electrical pathways combine.

On the other hand, the third prong on a grounded plug, like an extension cord ground for safety, connects to a metal plate in appliances. Therefore, it channels the voltage generated during power surges away from appliances and tools.

Advantages of Grounded Plug Cords

Grounded plug cords have numerous advantages that make them a viable choice compared to non-grounded plugs. Below is an overview of the said advantages.

• For starters, the third prong in grounded plug cords functions as a safety feature, eliminating the need to purchase additional safety features like grounding locking connectors. Grounding locking connectors are lock-and-twist devices with integrated poles and wires that you insert into a wall power outlet to carry current.
• Second, grounded plugs are compatible with most electrical devices and power outlets; hence are readily available and eliminate the need for adapters.
• The earthing prong’s safety function as a circuit breaker protects appliances from damage.
• Grounded plug cords typically feature double insulation as an enhanced safety feature against electrocution. Double-insulated plugs feature a symbol with a small box encased in a larger one to help consumers identify this feature while shopping.

Which appliances are compatible with grounded plug cords?

As stated above, grounded plug cords are compatible with more appliances than ungrounded ones. Such appliances include high-energy consumption devices like laptops and PCs, most small and large appliances in the home, and power tools.

Moreover, extension cords that connect to such appliances when the power outlet is too far away from the devices must also have a grounding feature. Otherwise, a grounded appliance with a grounded plug remains a potential electrocution hazard if the power receptacle, power strip, or extension cord is not grounded during power surges.

Alt text – electrical cord, bulk extension cord wire

Non-grounded Plug Cords

Unlike a grounded plug cord, a non-grounded plug cord, also known as a floating device, features only two parallel prongs. The first prong goes into the neutral slot in a wall power outlet, while the second goes into the hot slot.

Consequently, non-grounded plug cords have an increased risk of causing electrical shock and damage to appliances due to the lack of a grounding mechanism to function as a circuit breaker. Moreover, floating plug cords emit an electrical field up to a 6-8 ft range. The electrical field couples with conductors like metal, water, and the elements in the body that carry an electrical charge, increasing the risk of electrocution for persons within the range.

Which appliances are compatible with non-grounded plug cords?

Although ungrounded plug cords have an increased risk of causing electrocution, you can use them to plug devices with minimum energy consumption. Such devices include mobile phone chargers and shavers.

Alt text – extension cord, switch power cord

Conclusion

Grounded plug cords are a better option to keep your home and appliances safe. However, the safety feature in grounded plugs only works if you connect them to a grounded power outlet. Therefore, you should never remove the earthing prong on a grounded plug to make it fit into an ungrounded receptacle. Also, taking extra precautions like using ground fault circuit interrupters (GFCIs) never hurts.