Crane & Lifting Equipment Electrical Safety Requirements
Disconnect Switches and Contact Protection
Components must be marked with a label indicating they are protected against unintentional direct contact with live parts. If circuit disconnect switches pass through rings or busbars, they must be protected against direct contact with a minimum degree of protection of IP2X. Maintenance disconnects may be omitted if the emergency switches specified in section 4.2 are connected to the installation’s input supply. For a single crane installation, the main
Read MoreBicycle Parts Explained: Wheels, Chain, Pedals
Bicycle Wheels (Rims)
Bicycle rims are typically made of aluminum alloys and are quite flexible, resistant, and light. They have wheels that are stronger and heavier than road wheels, and feature a series of holes on the left and right where the heads of the spokes connect. These drill holes are protected to avoid puncturing the inner tube. Rims also often have a hand protector and a larger hole where the valve of the inner tube exits.
Inner Tubes and Valves
The main difference between valve types
Read MoreAir, Combustion, and Carburetor Function Explained
Air Composition and Combustion Basics
Air Composition
Air is a mixture of various gases. Its approximate volumetric composition is 21% oxygen, 78% nitrogen, and 1% argon and other trace gases. For combustion analysis, this 1% portion (mainly argon) is often treated as nitrogen because it behaves similarly as an inert gas during the process.
The Combustion Process
The basic chemical reaction for the complete combustion of a hydrocarbon (HC) fuel with oxygen (O2) is:
HC + O2 → H2O + CO2
Different air-
Read MoreNetwork Transmission Media Types and Cabling
Transmission Media
Transmission media is the physical support that facilitates the transport of information. Its quality depends on its characteristics.
Transmission media can be:
- Mechanical
- Electrical
- Optical
- Electromagnetic
Note:
- The estimated investment for a cable installation should be around 6% of the total project cost.
- Approximately 70% of network problems are due to wiring faults.
Metallic Wiring Systems
Copper Cable
Copper cable is a common format for metallic wiring systems.
Advantages:
- Simple and
Mechanical Principles: Simple Machines, Gears, Transmissions
Machine Definition and Types
A machine is a device capable of reducing the effort required to perform mechanical work.
It consists of a group of mechanical elements, each performing a specific function or task within the overall machine.
Types of Machines
- Simple Machines: Require only one point of support.
- Compound Machines: Formed by two or more simple machines.
Principal simple machines include the lever, inclined plane, wedge, screw, pulley, and winch. Examples of compound machines include bicycles
Read MoreAerial Device Classification: Features and Requirements
- Aerial Device Classification: Must reach at least 65ft above grade.
- Quint (50–75): Tank & Pump Size – Supply/Attack Hose Lines – Ladders & Waterways.
- Water Tower (50–130): Below Horizontal to 90° & flows 1000gpm.
- Articulating Aerial Platform (55–85): Boom Sections with hinge. Up & Over.
- Aerial Ladder Apparatus (50–135): Most Common /WH: Ground to highest rung.
- Combo Telescoping/Articulating Aerial Device (90 – 174)
- Aerial Ladder Platform (85–110): Straight-Chassis 3-axle,