Effect of Current Cycling on Contact Resistance, Force, and Temperature of Bolted Aluminium-to-Aluminium Connectors of High Ampacity

The effect of current cycling on the contact 10ad, resistance, and temperature of bolted aluminum-to-aluminum joints of high ampacity has been studied. The results show that current cycling causes significant changes in the contact load, resulting in a drastic loss of contact force. Contact resistance is less affected by current cycling, and connector temperature shows a normal beating effect produced by the cycling current. A new accelerated current cycling test has been proposed. The test is based on the passage of relatively high current for short periods of time followed by longer cooling times. The results obtained from the new test indicate that this testing procedure is a valid alternative to those presently in use, and that it can be used as a method for detecting the deterioration of electrical connections. The results also show that the use of Belleville washers, plating, and lubrication i lnproves the performance of the bolted joints under current cycling conditions.