Vanguard Instruments

Vanguard Instruments

Vanguard Instruments is a US-based manufacturer specializing in electrical test equipment for power utility and substation applications. The company is best known for its EZCT series of current transformer (CT) test sets, which are used by utility engineers and power system maintenance teams to verify the accuracy, polarity, turns ratio, and excitation characteristics of current transformers installed in high-voltage substations and switchgear assemblies.

Current transformer testing is a critical maintenance discipline in electrical power systems: faulty or out-of-tolerance CTs can compromise protective relay coordination and revenue metering accuracy. Vanguard's EZCT test sets are designed for field portability while supporting comprehensive IEEE and IEC test procedures, making them suitable for both commissioning new installations and routine maintenance testing of in-service protection systems.

Key Product Lines

• EZCT series CT test sets for ratio, polarity, burden, and excitation curve testing
• High-current CT test sets for large power transformers and substation equipment verification

Industries Served

Vanguard Instruments equipment is used primarily by electric power utilities, independent power producers, transmission system operators, and electrical contractors specializing in substation construction and maintenance. Their test sets are standard tools for commissioning substation protection systems and for periodic maintenance testing of CT installations in power transmission and distribution networks.