Learning Center

Substation fundamentals,
written by the people who fix them.

Practical guides on load tap changers, GOAB switches, circuit breakers, and the maintenance schedules that keep them in service. No vendor marketing — these are the briefs we use internally when training new technicians.

Substation Fundamentals
What Is a Load Tap Changer?

Load tap changers are the moving parts inside a power transformer. They keep secondary voltage in spec while the transformer stays energized…

Maintenance Planning
LTC Maintenance Schedule: When to Inspect and Replace Contacts

There is no universal right answer for how often to pull an LTC. What matters is matching the cycle to what the unit actually does, and tren…

Substation Fundamentals
What Is a GOAB Switch?

Group-operated air-break switches, or GOABs, are three-phase disconnects that operate from a single shaft. They do the visible isolation wor…

Substation Fundamentals
Oil Circuit Breaker vs Vacuum Breaker: Choosing the Right Interrupter

The choice between an oil circuit breaker and a vacuum (or SF6) breaker comes up every time a utility retrofits a substation, builds a new b…