33kv High Voltage Single Phase Potential Transformer

Product Features:

1. Structurally, a 33kv high voltage single phase potential transformer can be regarded as a small capacity and high ratio step down power transformer. However, unlike a power transformer,  a potential transformer does not transfer energy for load supply. Instead, it plays an important role on measurement and protection.

2. The secondary circuit is connected to measuring instruments, protective relays, and automatic devices of which the voltage coils present a extremely high and essentially constant impedance. As a result, the secondary current is minimal, similar to the no load condition of a power transformer. Power consumption of a 33kv high voltage single phase potential transformer is extremely low, and the secondary voltage remains practically equal to the induced EMF, which is determined by the constant primary voltage. It ensures the required accuracy level for voltage measurement.

3. The secondary winding of potential transformers must never be short circuited. Under normal operation, the load of 33kv high voltage single phase potential transformer is a high impedance device, but if a short circuit occurs, the only limiting factor is the impedance of winding. This can lead to excessively high short circuit current, causing incorrect meter readings, false relay operations, or even permanent damage to the power transformer.

4. The terminal of both the secondary winding and the zero sequence winding must be grounded. If not grounding, a fault on the primary system could induce dangerously high voltages on these windings, which poses serious risks to connected instruments, relays, and personnel safety.

Technical Specification:

Product FAQ:

Q: What is the rated burden of a 33kv high voltage single phase potential transformer?

A: The rated burden generally ranges from 25 VA to 200 VA depending on the application. It ensures stable accuracy for measuring instruments and protection relays without overloading the transformer.

Q: How is the 33kv high voltage single phase potential transformer grounded?

A: The secondary winding is usually grounded at one point to maintain reference potential and to ensure safety. it helps to avoid floating voltages and reduce the risk of insulation failure.

Q: Can a single phase PT be connected for three phase measurement?

A: Of course. For a three phase system, three single phase PTs can be connected in a star or open delta arrangement, which depends on if full phase to phase and phase to ground voltages need to be monitored or not.