Allis-Chalmers TLG Reversing Switch Contact Arm

Overview

Reversing switch contact arm for the Allis-Chalmers TLG load tap changer, Allis-Chalmers OEM 5327. Machined to OEM dimensional specification, or reverse-engineered when the part is no longer available.

About the Allis-Chalmers TLG

The Allis-Chalmers TLG is a reactor-type load tap changer built into oil-filled power transformers for on-load voltage regulation. It uses a selector switch to pre-select the next tap position and a reversing switch to change polarity, with current commutated through an impedance reactor rather than interrupted directly. Contact wear on the TLG shows as erosion and carbon buildup on the moving finger contacts and stationary contact faces. The selector switch contacts are the first to show degradation because every tap change cycles through them under load. At Southern Switch, TLG contacts are machined from silver-bearing copper alloy to OEM dimensional specifications and are available individually or as a complete kit.

Why replace worn LTC contacts

Worn or burned tap-changer contacts raise resistance, run hot, and can lead to tap-changer failure. Precision replacements restore reliable switching and extend the service life of the LTC.

Stock, lead time & reverse engineering

Lead time is confirmed at quote; discontinued or hard-to-find parts are reverse-engineered from a sample, a drawing, or a model number. Based in Palm Harbor, FL, Southern Switch & Contacts manufactures and ships replacement parts to utilities nationwide, and has served the industry since 1982.