๐๐ฅ๐ฅ ๐๐๐จ๐ฎ๐ญ ๐๐ฎ๐ซ๐ซ๐๐ง๐ญ ๐๐ซ๐๐ง๐ฌ๐๐จ๐ซ๐ฆ๐๐ซ
- CT Test
- CT Loop Resistance & Single Earth Point
- CT Secondary Injection Test
- CT Primary Injection Test
First of all letโs discuss about current transformer tests and later we will discuss the secondary and primary injection. Current transformer is one of the most important measuring & protection device in modern Substations. Correct selection & performance of CT is mandatory for the correct operation & function of substation. If CT specification or functioning is not match it can effect the overall protection system, Revenue meter & energy meter performance & lake of decision making to take specific action in case of active & reactive power management system.
Therefore, before energization the following electrical test need to be conducted so that the overall health, performance & accuracy of CT should be perfect.
a. Insulation resistance test
b. Winding Resistance Test
c. Polarity Test
d. Knee Point Test
e. Current Ratio Test
Before going to perform electrical test Visual Inspection & Mechanical check is also need to be done.
*Inspect for physical damage
*Verify connection as per approved drawing
*Check tightness of all connections
*Check nameplate details
*Check all grounding are ok & secured
Now, letโs talk about electrical test.
In modern substation only one kit is used to perform all the test. We have to connect the primary & secondary connection from the kit like CT analyzer with easily accessible terminal to the CT but we have to make sure that the direction of injected current should be from P1-P2, fill out the informative form & run the test & it will give the report for all the above mentioned test except IR test. We have to make sure that the CT is used for metering or Protection while filling to form & expected result should be in accordance with FAT report.