Carbon Bonded Metal Graphite Material
Description
These Grades are comprised of Graphite combined with Copper or Silver and/or various other Metal Powders. The Graphite is added into the Mixture for Lubrication. The CG-grades are more commonly used on Slip Rings with high Brush Current Densities on High Standard or Low Voltage Machines with High Current Densities and not too extreme Commutation Conditions.
CG-grades have the following characteristics:
- high Electrical Conductivity,
- low Specific Resistance, as low as 8-10 µΩ/cm,
- low to very low Voltage Drop,
- low to medium Peripheral Speeds of up to 35 m/s, and
- depending on the Metal Content of the Carbon Brushes, the Current Density varies from 12 to 30 A/cm² for Continuous Operation and peaks or starting loads of up to 300% for short periods of time.
SG-grades have the following characteristics:
- very high Electrical Conductivity,
- very low to low Specific Resistance,
- very low Voltage Drop,
- low to medium Peripheral Speeds of up to 30 m/s, and
- this Grade is more commonly used for Very Low Voltage, Relatively High Current Ratings, Static Discharge Brushes and Tacho Generators.
Application
105A – CG5115: Most commonly used on slip ring motors, difficult commutation of low voltage, high and low current rated machines, low voltage battery operated vehicles and low voltage traction motors, also for locomotives’ earthing brushes, as well as low voltage, high current contacts, electro-plating processes, crane collectors, automotive i.e. starters and windscreen wipers.
SG22 – SG30: For very low voltage motors of 1-3 Volts and milli-amp ratings, where very low voltage drop and optimum conductivity is required. Also used as high current rated contacts. Typical applications: signal motors for the railways and tacho generators.
