CATHSED® Shaft Earthing Device: Advanced Protection Against Shaft Corrosion
The CATHSED® Shaft Earthing (Grounding) Device is engineered to meet specific ship requirements, including intermediate shaft diameter and quantity. When a ship’s propeller shaft turns, it becomes electrically insulated from the hull due to the lubricating oil film in the bearings and non-metallic bearing materials in the tail shaft. This insulation creates an electrical potential between the shaft and hull, accelerating corrosion. Additionally, the shaft insulation hinders the propeller and boss from receiving cathodic protection, whether through sacrificial anodes or an impressed current system.
This electrical potential can cause heavy currents to flow through the bearings when the oil film breaks down or becomes contaminated with seawater, leading to severe bearing pitting. Over time, excessive wear on the shaft bearings can occur. By properly grounding the shaft with a propeller shaft slip ring, you can extend cathodic protection to the propeller and avoid these issues.
Innovative Features for Long-Lasting Performance
The CATHSED® Shaft Earthing Device uses high silver content brushes running on a silver alloy slip ring to ensure consistent low conductivity, even in dirty conditions. The assembly features high silver/graphite compound brushes mounted in balanced brush holders. Each brush holder includes an adjustable spring tensioner, preset to the standard pressure for optimal performance. This configuration allows the brushes to last over a year, even under challenging conditions such as mechanical friction, sparks from the main engine, or high electrical potential from the stern bearing and propeller.
The earthing readings are continuously monitored via a mV meter, ensuring they remain below recommended levels. K.C. Ltd provides high-quality silver graphite brushes and durable silver slip rings, designed to endure harsh environments and deliver long-lasting performance.
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If you have any questions or require spare parts for your K.C. Ltd. system.
Key Features of the CATHSED® Shaft Earthing Device:
- Compact and lightweight design
- Complies with MAN Diesel requirements
- Monitors both current (Amp) and voltage (mV) readings
- Compatible with ship’s AMS for data communication and alarms
- Simple installation for new builds and retrofitting ships
