# How do I choose a cable size for a specific load?

## How do I choose a cable size for a specific load?

Full Load Current = (KVA · 1000) / (1.732 · Voltage): Full Load Current = (100 · 1000) / (1.732 · 415) = 139 Amp….Let’s select 3.5 core 95 Sq.mm cable for single run, short circuit capacity = 8.2 KA.

- Current capacity of 95 Sq.mm cable is 200 Amp,
- Total derating current of 70 Sq.mm Cable = 200 · 0.93 = 187 Amp.

## How do you calculate wire size for a load?

Wire Sizing Chart and Formula

- Calculate the Voltage Drop Index (VDI) using the following formula:
- VDI = AMPS x FEET ÷ (% VOLT DROP x VOLTAGE)
- Determine the appropriate wire size from the chart below.

**How do I choose a wire size?**

There are two pieces to the wire size question: thickness (gauge) and length. To determine what gauge wire you need, consider the carrying capacity and the amount of current the wire needs to conduct (measured in amperage or amps). Wire gauge is directly related to how many amps you need to run through it.

**How much load can a 1 sq mm wire take?**

Then according to this algorithm we know: copper wire per 1 square millimeter area, if the 220V is used in single-phase circuit, it can safely carry the load current through the 1KW; if used in three-phase balanced load (such as motor) circuit, can safe current carrying load by 2.5KW.

### How is the size of a wire chosen?

Wire size should be selected solely for its current capacity as shown in Chart 1. On longer runs, say several hundred feet or more, the voltage loss may be excessive even though the wire has been selected to carry the current without overheating.

### Is there a limit to how much current a wire can handle?

Each wire size, or wire gauge (AWG), has a maximum current limit that a wire can handle before damage occurs. It is important to pick the correct size of wire so that the wire doesn’t overheat. The number of devices connected to the circuit usually determines how much current will flow through the wire.

**What are the trade offs in wire selection?**

This document may be reproduced mechanically or electronically for non-profit, educational purposes when produced in its entirety and without modification. Wire Size Selection Trade Offs Between Keeping it Cool and Getting Power to the End of the Wire . . . .

**How to calculate the carrying capacity of a wire?**

The calculation is a step by step approach and several graphs are used to obtain information to compute the current carrying capacity of a particular wire.