Design of standard instruments, relays or equipments normally does not permit them to be considered directly to the high voltage systems. Potential transformer therefore play a key role hereby performing the following functions:
- For electrically isolating the instruments and relays from the high voltage side.
- For transferring voltage from higher values to proportional lower values upto 63.5V, 100V and 110V as per the standard of equipment.
Types of PTs
- Indoor Epoxy Resin cast.
- Outdoor Oil cooled Type.
The class of accuracy for metering PTs are 0.1, 0.2, 0.5 and 1.0 and protection of PT is 3P.