# What is the greatest load a wire with cross-sections of 1.5 mm² // 2.5 mm² // and 4 mm² can withstand

• Apr 08, 2021
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The cross-section of the conductor is the most important parameter that must be taken into account, since the safety of your home depends on it. If you just buy the first cable you come across and decide to use it to connect an electric oven, it will be a huge mistake.

If the diameter is insufficient, the conductor will start to overheat. As a result, the wire insulation can melt, and this leads to a short circuit. In the worst case, there will be ignition and fire.

## Wires with a cross section of 1.5; 2.5 and 4 square millimeters: how much power they withstand

To determine the direct load that a cable is capable of emitting, you need to use the following proportion: each square millimeter of a copper cable can withstand no more than 10 Amperes of current.

It sounds scary and difficult, but in reality everything is simple. It is only necessary to convert Amperes to kW.

10 Amperes is approximately 2 kW. It turns out that a 1.5 mm cable can handle about 3.5 kW. Similarly, you can calculate how much power cables of other cross-sections can withstand. For simplicity of calculations, I have given you a table, which is better to save somewhere so as not to lose.
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It is also worth saying that a 3-phase network has a voltage of 380 V, which means that the power and current values ​​in it will be different. It is necessary to take into account the materials from which the cable is made. Conductors of the same cross-section, but made of different materials, will withstand different loads. For example, copper is more "hardy" in this respect than aluminum.

## How to calculate the load carrying capacity of copper cables

• 1. A conductor with a cross section of 1.5 square millimeters is capable of withstanding no more than 3.3 kW;
• 2. Conductor with a 2.5 mm cross-section - no more than 4.5 kW;
• 3. Cable with a cross section of 4 mm2 - within 6 kW.

These values ​​are valid when it comes to a single-phase network with a voltage of 220 V, and the cables are made of copper.

If there are 3 phases in the network, then the indicators of the permissible capacities of the conductors will be higher.

## What to look for when choosing a wire?

When choosing cables, you need to rely on 2 main parameters:

• 1. The load that the cables will experience during operation. It is important to know how many electrical appliances will be "powered" from this cable.
• 2. The rated value of the circuit breaker. It must correspond to the amperage passed through the cable.
If your home has regular outlets, you can purchase a 2.5mm copper cable. These sockets can be connected to electrical appliances, whose power does not exceed 2 - 3 kW. The total power of all appliances must be less than 3.5 kW (about 16 Amperes).
To connect devices from the lighting group, a 1.5 mm cable is enough. To power the electric stove, you should choose a wire with a cross section of at least 4 or 6 square millimeters.

If you know the maximum permissible load on the wire, then you can easily make the right choice.