Allis Chalmers LTC – Internal Inspection – Required adjustment of operating mechanism, it was not commutating properly between taps. Trigger device on indexing cam was not working properly. Other service on this design includes replacement of re-versing switch contacts due to severe coking along with the reversing switch drive shafts. We have also worked on control problems resulting in change out of micro-switches internal to oil compartment.



GE LRT 72 – Inspection – Unit was found to have a slight water leak in large mechanical relief gasket allowing water to leak into the compartment. Cleaned up the rust, painted the affected area and re-gasketed the large PRD. Also repaired the paper taping as needed on the leads. This unit was found to have 2 phases with cracked moving contact mounts on the operating shaft. These were replaced, flushed and filled with new oil.



The operating shaft on this unit is a hardwood design with a blind pin holding the moving contact mounting collar in place. Special tooling is required to properly locate the replacement moving contacts.


GE Vacuum tap changer – model LRT 200-2 after installation – Original unit had a fiber drum which was distorted and had a burned by-pass switch. This unit was purchased from High Voltage Supply – Texas as a replacement and installed.


LRT-200-2 replacement tap changer with high current leads formed prior to installation. A dummy terminal board was fabricated and attached to this unit so the leads could be precisely preformed for installation in an extremely tight area. The original unit that came out had flexible lower current leads; this was provided as a higher current replacement with copper strapped leads.


Westinghouse UTT-B LTC – cleaned, inspected, tested – led to transfer switch contact replacement.

Transfer switch contacts – note the holes in the contact surface.

Waukesha Tap changer UZD – cleaned & inspected – ready to close and fill.


McGraw drive gear box – taken apart for motor replacement.

Waukesha UZE tap changer – before clean up.

Reinhausen Vacuum tap changer – one phase with vacuum bottle - tap selector switch located behind.