Are you struggling with power losses and voltage drops in your electrical system? Parallel cable connections may be the solution.

By dividing current among multiple conductors, parallel cables reduce resistance and improve efficiency.

In this article, we’ll explore the fundamental principles behind parallel cable connections.

What is Parallel Cable Connections

Parallel cable connections refer to a wiring configuration where two or more electrical conductors are connected at both ends, creating multiple paths for current to flow between the source and the load. This arrangement is analogous to a parallel circuit consisting of discrete electrical components, where each component shares the same two electrical connection points.

Fundamental Principles of Parallel Cable Connections

The behavior of parallel cable connections is governed by the same principles that apply to parallel circuits in general. According to Kirchhoff’s current law, the algebraic sum of the currents entering and leaving a node in a circuit is zero. In a parallel circuit, this means that the total current provided by the source is equal to the sum of the currents flowing through each individual branch.

Another characteristic of parallel circuits is that the voltage across each component or branch is the same. In the case of parallel cables, this means that each conductor experiences the same potential difference between the source and the load. As a result, the total current demand of the load is divided among the parallel conductors, with each conductor carrying a portion of the total current.

Resistance of a Parallel Circuit

The total resistance of a parallel circuit is always less than the resistance of any individual branch. This is because adding more paths for current flow effectively reduces the total resistance to current flow.

The total resistance (R total ) of parallel resistors is calculated as:

1/R total = 1/R 1 + 1/R 2 + … + 1/R n

where R 1 , R 2 , …, R n are the resistances of the individual branches. For cables in parallel, assuming the cables are identical, the equivalent resistance of the parallel combination is lower than that of a single cable. This reduced resistance helps minimize power losses in the form of heat (I 2 R losses) and results in a smaller voltage drop for a given current.

Why Use Cables in Parallel

• Ampacity: When the current required by the load exceeds the maximum ampacity (current-carrying capacity) of a single available cable, using multiple cables in parallel can divide the total current among them, ensuring that no single cable is overloaded. This allows for the safe transmission of higher currents without the need for a single, larger, and potentially more expensive cable.
• Ease of installation: In some cases, it may be easier to install multiple smaller cables rather than a single large cable. This is especially true when the installation space is limited or when the cables need to be routed through tight spaces or conduits.
• Economic factors: Using parallel cables can be more cost-effective than using a single larger cable, particularly when the required cable size is not readily available or when the cost of a larger cable is disproportionately high compared to the cost of multiple smaller cables.
• Simplicity: It is usually simpler to terminate smaller gauge cables than very large gauge cables. Larger cables may require specialized tools and connectors, whereas smaller cables can often be terminated using standard tools and techniques.
• Keep voltage drop low: By reducing the overall resistance of the circuit, parallel cable connections help keep the voltage drop low.