Can I Use 2 Smaller Wires to Replace a Larger Gauge Wire?

In the world of electrical wiring, it is often asked whether it is possible to use two smaller wires to replace a single larger gauge wire. The answer is both simple and complex, depending on various factors. Let's delve into the details and explore when and how this can be done safely.

Theoretical Perspective

Conceptually, it is possible to use two smaller wires to replace a larger gauge wire. This is based on the fact that resistance is inversely proportional to the cable's cross-sectional area. Generally, a wire diameter that is half the size of the original wire will have a quarter of the cross-sectional area. To achieve the same resistance as one larger wire, you would need four smaller wires.

However, this concept also takes into account heat dissipation. Four smaller wires might dissipate heat more effectively than one larger wire, potentially allowing for a slightly higher current to be carried. This added heat dissipation can be an advantage in certain applications, but it doesn't automatically make it safe to use multiple smaller wires in place of a single larger one.

Practical Considerations

From a practical standpoint, using two smaller wires to replace a larger one is often considered unsafe. The reason for this is the need to make very solid, low-resistance connections on both ends of the two parallel wires. Achieving this consistently is a challenge that requires both practical experience and theoretical knowledge.

Most people, without proper skill, will introduce high-resistance connections, which can lead to overheating and a potential fire hazard. It is important to note that no one can determine the proficiency level of a person online, hence the safest advice is to avoid using two smaller wires to replace a larger gauge wire.

Code Permits and Exceptions

There are certain times when using two smaller wires can be permitted, but only under specific conditions. For instance, the NEC (National Electrical Code) and CEC (Canadian Electrical Code) permit parallel smaller wires for gauge wire larger than 1/0 (AWG).

Furthermore, some codes and practices allow for this substitution in cases where the circuit's load is unexpectedly high. However, it is crucial to ensure that the total carrying capacity of the two smaller wires is equivalent to the required load. This means you need to calculate the cross-sectional area of the original single cable and then find two smaller wires that together match that area.

Circuit Protection Concerns

Another important factor is circuit protection. If a single conductor in the parallel wires were to fail, it could result in an overloading of the other conductor, leading to circuit protection issues. This underscores the importance of using the correct gauge wire and ensuring that the connections are secure and low-resistance.

Stranded Wires as a Solution

Stranded wire is a type of wire that is composed of many smaller wires bundled together. The purpose of using stranded wire is to make it more flexible and easier to bend around corners. This type of wire is not only used for preventing damage but is also a practical choice in many electrical installations.

When using smaller wires as a substitute for a larger gauge wire, it's worth noting that if the wires have a plastic coating, you don't need to strip it off. Instead, focus on ensuring that the cross-sectional area of the smaller wires matches that of the larger one. The old term "AWG14" has been replaced by measurements in Square Millimeters, which makes it easier to determine the equivalent cross-sectional area for the smaller wires.

Conclusion

In summary, while it is theoretically possible to use two smaller wires to replace a larger gauge wire, it is generally not recommended due to the risks involved. This approach is safe only in specific situations and requires precise knowledge and skill. For most applications, it is best to adhere to the recommended gauge wire to ensure safety and reliability.