McGraw-Edison 550 Series LTC Parts
The McGraw-Edison 550 series is one of the most installed distribution-class LTC families in the United States. The base 550, the 550-CS, and the 550-BLS share many parts, but they diverge in moving-contact assemblies and locking-tab designs.
The base 550 is a straightforward diverter-switch design. The 550-CS adds reinforced reversing-switch contacts for higher-load applications. The 550-BLS introduces a redesigned drive shaft and a different selector-switch arrangement.
All three families are still in service across the southeastern United States and remain refurbishable with reverse-engineered contacts. Cross-compatibility notes are on each kit page. Many 550 stationary contacts swap into the 550-CS, but the reversing-switch parts do not interchange.
The 550 series moving contacts pivot through the arcing zone on every tap operation. The silver plating on the contact finger erodes first. Once it is gone, the underlying copper oxidizes and contact resistance climbs. Replacement contacts restore the silver-plating arc resistance and the spring tension that holds them against the stationary face.
Kit · LTC Contacts
Kit · LTC Contacts
Kit · LTC Contacts
Kit · LTC Contacts
We refurbish and reverse-engineer parts for every McGraw-Edison LTC ever built. Send us a model number or photo and we’ll quote within one business day.