Instrument Transformers - DVD
This 31-minute DVD explains what instrument transformers are and how they are typically used. It describes different methods of connecting current transformers (CTs) and voltage transformers (VTs) in single-phase and polyphase service.
Instrument Transformer Applications – 4 minutes
Describes the main functions of instrument transformers. Identifies factors that determine when instrument transformers are required.
Current Transformers – 7 minutes
Distinguishes between bar-type current transformers and window-type current transformers. Identifies the main components of a typical current transformer. Describes how a current transformer’s fixed current ratio can be determined and indicated. Describes how a current transformer’s polarity can be indicated.
Current Transformer Connections – 6 minutes
Describes how two CTs can be connected in a single-phase, three-wire service. Shows how one CT can be connected in a single-phase, three-wire service. Explains how three CTs can be connected in a three-phase, four-wire service.
Voltage Transformers – 7 minutes
Identifies the components of a voltage transformer. Defines burdens and accuracy class.
Voltage Transformer Connections – 7 minutes
Describes how a voltage transformer can be connected with a single-phase primary service. Describes how voltage transformers can be connected with a three-phase primary service.