Factors in Contactor Contact Design
The following factors are considered when designing contactor contacts:
Current-Carrying Capacity
The current-carrying capacity of contacts is a primary consideration in design, directly influencing material selection. Hard-drawn copper or forged copper are preferred choices to ensure optimal performance.
Contact Pressure
Contact pressure is directly proportional to current-carrying capacity—an increase in pressure enhances the contact's ability to carry current. However, there is a critical threshold beyond which further pressure increases offer diminishing returns. Optimal pressure must be determined to balance performance requirements.
Contact Mass
Heat dissipation from contacts is directly related to their mass. Therefore, contact mass is a key parameter in design, requiring careful consideration to balance thermal management with mechanical durability.
Heat Radiation Design
Designers must define power loss at specified temperatures and optimize contact geometry to maximize the effective radiation surface area, thereby enhancing heat dissipation efficiency.
Contact Surface Condition
Contact surfaces must be clean, smooth, and free of oxide layers. Roughness, corrugation, or darkening can increase contact resistance. If degradation occurs, surface refinishing or complete replacement may be required.
These are the factors affecting contactor contact design. In subsequent posts, we will discuss overall contactor design.
