The electrical contact testing is performed to determine the reliability of equipment under various contacting conditions. A few types of electrical contact tests are: contact-chatter monitoring, contact resistance, intermediate, and low level contact switching.
This test is conducted for the purpose of detecting contact-chatter in electrical and electronic components having movable electrical contacts, such as replays, switches, circuit breakers, etc. It is performed where it is required that the contacts do not open or close momentarily, for longer than a specified time-duration, under environmental test conditions, such as vibration, shock, or acceleration.
Contact-chatter testing is specified in the following:
The purpose of the contact-resistance test is to determine the resistance offered to a flow of current during its passage between the electrical-contacting surfaces of connecting components, such as plugs, jacks, connectors, and sockets, or between the electrical contacts of current-controlling components, such as switches, relays, and circuit breakers.
Contact resistance testing is specified in the following:
INTERMEDIATE LEVEL CURRENT SWITCHING
This test is conducted for the purpose of determining the electrical contact reliability of such items as electromechanical relays, switches, etc., under intermediate current switching conditions. An intermediate current switching circuit is one in which there is insufficient voltage and stored energy to cause contact arcing during opening or closing of mating contacts, but which have sufficient energy to cause melting of the contact material.
Intermediate level current switching testing is specified in the following:
LOW LEVEL CONTACT SWITCHING
This test is conducted for the purpose of determining electrical contact reliability under low-level switching conditions in the environment in which the contacts operate. A low level switching circuit is one in which the voltage and stored energy are sufficiently small so that the resistance of a pair of contacts is not affected by electrical phenomena associated with the electrical current flow or the switching.
Low level contact switching testing is specified in the following: