The effect of mechanical parameters of switch-type contact on relay operation characteristics

Electric arc erosion during contact break/make cause contact resistance degradation, material transfer, non-closing and non-opening, above failure modes affect relay operation characteristics greatly. A relay model testing device which could simulate relay parameters of: initial contact force between N.C. contacts, contact gap and N.O. over-travel mechanical parameters assembly was used to study arc erosion. During breaking and closing operation, contact resistance, pick-up/release voltage, pick-up/release/arc duration were recorded explicitly during test. The optimal matching mechanical parameters assembly of switch-type contact was determined by test results comprehensively. Therefore the contradiction between reducing arc duration and lower bouncing time was solved in maximum extent. The conclusions drawn in this paper are meaningful for optimization of mechanical parameters of switch-type contact in relay.