Electrical Cable Protection: Overcurrent, Overvoltage & Fault Detection
Protection Against Overcurrent and Overvoltage
The goal of protecting cables and limiting surge currents is to prevent them from exceeding their maximum allowable temperatures and to prevent potential fires.
Overloads
A facility or part of it is considered to be subject to an overload when, for some time, it is traversed by a current greater than the normal or assigned current, without any malfunction or failure in the installation. In short, the surge produces a reduction in the life of conductors.
Read MoreElectrical Installations in Homes and Buildings: A Comprehensive Guide
Electrical Installations in Homes and Buildings
Introduction
The increasing complexity of electrical installations in buildings requires professionals to consult regulations, standards, and manuals for practical application. This guide provides an overview of the main components of electrical installations in homes and buildings.
Parts of an Electrical Installation in a Home
The main parts include the service entrance, main panel, branch circuits, outlets, and fixtures. A sketch of a typical installation
Read MoreMaterials Science: A Comprehensive Guide
Alloys, Fluxes, and Steelmaking
What are the alloys and fluxes in the oven?
Fluxes remove slag, while ferroalloys improve steel properties.
Why can’t converters be added with pig iron and fluxes at the beginning?
Ferroalloys and fluxes would be removed with the initial slag.
What is the hottest part of the blast furnace where iron ore melts?
The bosh.
How is steel produced?
By blast furnace, furnace refining, and electric oven.
Blast Furnace Operation
Iron ore, fluxes, and coke are introduced. As they descend,
Read MoreHard Disk Drives and Storage Principles
Storage Principles
Magnetic Storage
Devices using this principle have a storage area consisting of many magnetic particles:
A particle oriented in one direction stores a logical 1, while another particle oriented in another direction stores a logical 0. These devices have read heads (a small coil of wire that when a current passes through it, creates a magnetic field that polarizes a point on the surface) and writing heads (the current in the coil comes from the own magnetic field of the magnetized
Read MoreMechanical Coupling Elements and Joining Techniques
Mechanical Coupling Elements and Joining Techniques
Gears
Pinion Gear
A normal 13-tooth pinion gear meshes with another gear whose radius is infinite. This system’s function is reversible.
- If the pinion is fixed and the rack moves, the pinion rotates without moving the rack.
- If the pinion rotates while the rack is fixed, the rack will move.
Screw-Nut
The screw-nut mechanism is used to turn the screw while preventing the nut from turning. The concept of a screw propeller is derived from a ramp wrapped around
Read MoreMetalworking Hand Tools and Techniques Guide
ITEM 10: Filing and Sanding Techniques
Filing
Technical Filing: Aims to reduce areas where material removal is necessary. Metal removal can be done manually or mechanically.
Files:
- Made of hardened, extra-hard steel plates.
- Carved on their surface to facilitate the start of chips in the direction of file movement.
- Carving consists of cutting teeth.
Characteristics of Files:
- Size: Body length is the distance between the point and the heel of the file.
- Shape: Flat, triangular, square, half-round, round, knife.