Temperature rise test of transformer.
Medium voltage current transformer testing.
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 transformer substation heat run test requires the transformer mv and lv switchboards to be tested at the same time with defined currents.
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The test is successful if no breakdown occurs at full test voltage during the test.
After commissioning secondary current measurement shall be carried out in ct circuits.
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.
Instrument transformers current transformer.
In this test.
The importance of instrument transformer tests is often underestimated.
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.
A current transformer without primary conductor but with primary insulation of its own which can be used as a bushing.
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.
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Temperature rise test of transformer is included in type test of transformer.
Phase angle check shall be done for correct direction.