Medium Voltage Current Transformer Testing

In this test.

Medium voltage current transformer testing.

A transformer substation heat run test requires the transformer mv and lv switchboards to be tested at the same time with defined currents. Ct s are instrument transformers used for converting primary current into a reduced secondary current for use with meters relays control equipment and other instruments. The test is successful if no breakdown occurs at full test voltage during the test. Phase angle check shall be done for correct direction.

Common specifications for hv switchgear. Indoor current transformers bushing type bb and bbo medium voltage current transformers bushing type bb and bbo are cast in epoxy resin and are designed for installation voltage up to 24 kv 25 kv. Practical levels of voltage are often referred to as medium voltage meaning the incoming voltage to the transformer is on the order of 5 kv to 35 kv. Th e test shall start with a voltage lower than 1 3 the full test voltage and it shall be quickly increased up to the desired value.

Go to content 5. The importance of instrument transformer tests is often underestimated. Temperature rise test of transformer is included in type test of transformer. Current transformers play an important role in the monitoring and protection of electrical power systems.

A current transformer without primary conductor but with primary insulation of its own which can be used as a bushing. Some distribution voltages may exceed 35 kv and would be considered high voltage but most of the distribution system is within the medium voltage range. Temperature rise test of transformer. After commissioning secondary current measurement shall be carried out in ct circuits.