Motor Operator Trip Free Failure
The above picture shows the trip link and the trip adjustment screw in the motor mechanism assembly. The trip link to the above left is made from aluminum and the screw from steel. The trip adjustment screw can wear an indentation into the trip link causing the motor mechanism to go out of adjustment and not operate properly. Correcting this problem requires the switch to be opened and readjusted.
The Vacuum Electric Switch Co. offers as a replacement part the link shown to the right. It has the same weight and is functionally as the link to the left, but it is made of steel. The steel screw on a steel link provides a much better wear combination and eliminates the need for frequent readjustment.
Motor Operator Contact Blocks
The motor operator contact blocks have had many previous versions two of which are pictured to the left. The upper picture was the original design which performed well. It is no longer manufactured and replacement parts are difficult to find. The lower left picture shows a recent contact block made from Square D™ contact assemblies. The Square D™ contact assemblies frequently failed by cracking in the plastic housing.
The picture to the lower right is Vacuum Electric Switch Co’s new contact block which has the foot print and functionally of the original block shown in the picture to the upper left. This new block uses Allen Bradley™ contacts, housing, and yoke. An additional advantage of this contact blocks is the ability to individually remove and replace bad contacts without having to replace the entire block or to readjust the positioning of the block.