Electrical Installation Drift Currents

Study Notes

Elanläggningens Driftsströmmar

Driftsströmmar refer to the currents that occur during normal operation of an electrical installation, such as when lights are on and machines are functioning as intended.
These currents are different from short-circuit currents, as they are continuous and last for many hours, putting a different type of load on the installation's components.
To plan and design an electrical installation, it's essential to consider the driftsströmmar and choose the right size and dimension of components.

Parallellkoppling

In an electrical installation, all loads are connected in parallel.
Each central unit is fed via a main line and serves as a distribution point for different groups.
Each group can then branch out to multiple loads.

Electrical Circuits

A circuit diagram shows how different components interact with each other.
The diagram includes elements such as a fuse box, transformer, light bulbs, plug socket, and conductors (wiring).
The diagram is labeled with technical details, including voltage, current, resistance, and power.
The circuit is a "group distribution" circuit, meaning it has multiple outlets and feeds multiple outlets.
The switches on the fuse box control the flow of electricity to the outlets.
The parallel connection of the outlets means each outlet receives the full voltage from the circuit, regardless of whether the other outlets are in use.

Circuit Elements

A circuit diagram may include elements such as a coffee maker, light bulb, electric kettle, hairdryer, and power outlet.
Each element has its own resistance values, current values, and voltage values.

Understanding the Circuit

The circuit consists of multiple branches, and the sum of the current in each branch is equal to the total current (based on Kirchhoff's Current Law).
The total resistance of the circuit can be calculated using the formula, $R_{total} = R_1 + R_2 + R_3 +...$.
The total current can be calculated using Ohm's law, $I_{total} = \frac{V_{total}}{R_{total}}$.

Description

This quiz covers the currents that occur in an electrical installation during normal operation, ensuring lamps and machines function as intended. It discusses the importance of planning and selecting suitable materials for drift currents.