The two types of wires- solid wire and stranded wire are widely used in electrical systems. Wires are electrical conductors that carry the electric current and they are the most important component of the electrical system. Electric power can not be transmitted without electric wires.
In this article, we will discuss in detail what solid wire and stranded wire are and what are the major differences between them. Now, we first understand what are solid wire and stranded wire.
What is a Solid Wire?
As its name suggest a solid wire has one solid conductor that carries electric current. The conductor is made of aluminum or copper, and it has a uniform cross-section area along its entire length. The solid wire is rigid and it is not flexible, and they are suitable for those applications where flexibility is not a major concern.
The solid wire is more apt to fatigue and breakage if it is used on those applications where there is more movement and vibrations.
Solid wires are cost-effective, weather-resistant, easy to use, and anti-corrosive, and It is widely used in residential, commercial, automotive, and electronics wiring. The solid wires are comparatively heavier.
What is a Stranded Wire?
If we use large numbers of thinner wires and twist them together to unify them, then a single conductor has a number of thinner conductors and it is called a stranded wire. In contrast to solid conductors, the stranded conductors are flexible and delicate. If they are frequently bent, the strands may damage. Therefore, the stranded wire is not suitable for those applications where there is frequent bending and twisting, such as wiring in the door of the car.
A type of wire in which each conductor consists of a large number of thinner wires twisted together into a bundle is called a stranded wire. The stranded wires are more flexible and delicate. Therefore, they are used in such applications where bending and twisting are required such as in the case of a door of a car.
A stranded wire is flexible, malleable, and delicate in comparison to a solid wire. The stranded wire is likely to affect by weather conditions and surrounding environmental conditions. They have a gap between the strand and moisture and other foreign material may deposit between the strand, and it causes resistance of the wire to increase over time. Therefore, the stranded wire is more suitable for indoor applications and for those applications where flexibility is a major concern, such as electrical machine wiring, circuit board wiring, and vehicle wiring.
Difference between Solid and Stranded Wires
Solid wire and stranded wire are widely used in numerous electrical applications. For some applications, the solid wire is the best choice, whereas the stranded wire may be the best for some applications. The major differences between solid wire and stranded wire are given in the below table.
| Basis of Difference | Solid Wire | Stranded Wire |
|---|---|---|
| Definition | A wire which has one solid metal conductor is known as solid wire. | A solid wire is less flexible compared to a stranded conductor. |
| Electrical resistance | It offers comparatively less electrical resistance. | It offers comparatively higher electrical resistance. |
| Wire flexibility | Wire ampacity | Stranded wires are highly flexible, and they can be bent easily. |
| The ampacity- current carrying capacity- of the solid wire for the same wire size is more and it can carry more current. | Solid wire produces less noise because of the uniform cross-section area. | The ampacity- current carrying capacity- of the stranded wire for the same wire size is less compared to solid wire. |
| Corrosion | The solid wires are not prone to corrosion, and these wires can be used for indoor & outdoor applications. | The stranded wires can sustain more vibrations and repetitive motion, and therefore these wires have a longer life if operated under vibrations. |
| Effect of Vibrations | The stranded wires have a more effective cross-section area and, thus the skin effect is less. | The effective cross-section area reduces because of more skin effect in the solid wire. |
| Skin effect | The termination and connection of a stranded conductor are intricate. | The termination and connection of a stranded conductor is intricate. |
| Voltage drop | The solid wire has less voltage drop. | The stranded conductor has more voltage drop. |
| Termination & connection | It is easy to terminate the solid wire. | Stranded wire has less proximity effect because the wire strands reduce the overall magnetic field generated by the current and thus, it creates a more uniform distribution of the current. |
| Proximity effect | Solid wire has more proximity effect because there is no stranded structure to oppose the magnetic field generated by the current. This causes uneven distribution of magnetic field over an entire length of the wire. | Stranded wires are suitable for such applications where flexibility is required, like computers, circuit boards, etc. |
| Noise | A stranded wire has medium performance at high frequency. | A solid wire has good performance at high frequency. |
| Cost | Less expensive | More expensive than solid wire |
| Operation at high frequencies | Stranded wire produces more noise with an attenuation of 20 to 50 % because of the non-uniform cross-section area. | Stranded wire is suitable for short-distance applications. |
| Suitability | The solid wire has less voltage drop and they are suitable for long transmission power transfer. | Stranded wires are suitable for comparatively short-distance applications. |
| Applications | Solid wires are suitable for outdoor applications where high ampacity and more durability is required. | Solid wires are suitable for outdoor applications where high ampacity and more durability are required. |
Conclusion
The most significant difference between the solid and stranded conductors is the difference in their construction. The solid wire has only a single solid metal wire, while a stranded conductor has many strands of thin wire twisted together.