Medium Voltage Current Transformer Testing

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Medium voltage current transformer testing.

Go to content 4. Phase angle check shall be done for correct direction. The test is successful if no breakdown occurs at full test voltage during the test. 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.

Temperature rise test of transformer. 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. Two ac power supplies are needed one high power supply for the mv switchgear and the transformer in short circuit and a high current supply for the lv switchboard. A current transformer without primary conductor but with primary insulation of its own which can be used as a bushing.

Temperature rise test of transformer is included in type test of transformer. 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. The importance of instrument transformer tests is often underestimated. A transformer substation heat run test requires the transformer mv and lv switchboards to be tested at the same time with defined currents.

Instrument transformers current transformer. Current transformers play an important role in the monitoring and protection of electrical power systems. Common specifications for hv switchgear. 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.