The new VBU™ module is VES part no. 1002719G2, shown at above right. At left, a drawing showing how a Mitsubishi™ vacuum interrupter is installed in the module.
The VBU mechanism above VES part No. 1004429G1 has been reverse engineered and remanufactured to be like the original Joslyn™ mechanism design. The adjustment cams have been reincorporated the same as in the original design. The cam can be seen in the above picture. The Square D™ contact blocks shown at left above been replaced with Allen-Bradley™ contactors as shown in the center above. They are mounted on the side of the VBU mechanism as shown to the above right.
When VBU switches are used on arc furnaces, the causes of down time can be categorized as being attributed to modules, operating mechanisms, and controls. Design changes in remanufactured modules have eliminated almost all routine failures in modules. Design changes in the reverse engineered mechanism above have enabled that mechanism to exceed 100,000 operations in life testing. The control problems have been addressed by the control shown here. Diagnostics are part of this control’s program. This control is an adaptation of the control here for which there are more twenty installations.