McGraw-Edison 550-CS Kit

Overview

Contact kit for the McGraw-Edison 550 CS LTC, main moving, 2- and 3-finger reversing moving, main and reversing stationary, neutral, and locking tab. This is the correct kit for tap changers cataloged as the McGraw-Edison 550C.

About the McGraw-Edison 550

The McGraw-Edison 550 is a reactance-type arcing tap switch and one of the most widely deployed LTCs in utility power transformers across North America. During a tap change the contacts bridge two taps briefly through a preventive autotransformer that limits the circulating current, and the arcing contacts open and close under load current on every operation. The main moving contact, stationary contact, and reversing switch contacts bear that duty on every tap change. At 50,000 operations or the manufacturer's recommended inspection interval, contact condition directly determines whether the tap changer will perform reliably between outages.

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.