- The COMPANO 100 test set can output life-hazardous voltages and currents.
- Before operating any such electrical equipment, carefully read the Safety Instructions chapter in this manual (see Safety instructions).
| WARNING | ||
| Death or severe injury can occur if the appropriate safety instructions are not observed.
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This chapter provides you with examples how to perform basic tests on a current transformer (CT). These tests are done as well when you check the secondary wiring of the CT (see Wiring tests (application example)). If you check the CT ratio or the CT burden with COMPANO 100, it is not necessary to open the secondary wiring.
Connect COMPANO 100's output I OUT to the CT's primary terminals P1/H0 and P2/H1 using the high current cables.
The CT's secondary terminals S1/X1 and S2/X2 are connected to the current input of the relay (pins 8 and 9).
Configure COMPANO 100's input IN 1 to be a voltage input: press the IN 1 key below the actual input. Press the following soft keys sequentially: Analog ► Voltage ► AC ► Auto ► Accurate.
Verify that the CT’s secondary loop is closed and check the CT polarity
Inject an I OUT AC current of 1 A for a few seconds, and read out the voltage on IN 1. You should get to see a few millivolts, only.
If you see a voltage value of say more than 1 V, the secondary loop of the CT might be not closed, which is a safety issue. You should stop the test in that case.
Now set a timeout to 2 seconds, and inject an I OUT AC of say 100 A into the CT.
The interesting result of this test is the phase angle of the voltage:
If it is between 0 ° and 90 °, the CT's polarity is correct.
If it is between -90 ° and -180 °, the polarity is not correct.
In this first step, we have now verified that the secondary circuit of the CT is closed, and that the polarity of the CT is correct.
Connect the current clamp to the COMPANO 100 input IN 2.
Note: perform a DC current offset calibration on the current clamp before carrying the measurement.
At the current clamp, set a suitable current range, for example, 100 mV/A or 1 V/A, depending on the current clamp type and setting.
Configure COMPANO 100's input IN 2 to be a current input. Press the IN 2 key below the actual input. Press the following soft keys sequentially: Analog ► Clamp ► 100 mV/A* ► AC ► Auto ► Accurate.
*Select the value corresponding to the current clamp. Use the jog dial wheel to set a value differing from the preset.
Press the Calculated measurement key 
. Then press the jog dial wheel to turn it On.
Configure the calculated measurement by using the output current I OUT as operand 1, and the input current at IN 2 as operand 2.
Because both operands currents, the Calculation setting provides the ratio options Ratio:1 and Ratio:5. Select the proper ratio setting according to the secondary circuit 1 A or 5 A.
Return to the QUICK application module, inject a current of 100 A for 2 seconds, and read the ratio from the display.