22
ANSI MEDIUM VOLTAGE METAL-CLAD DIGITAL SWITCHGEAR
• Step 1/6
Verify sensor parameters set in the protection
relay with sensor rating plates found on the
sensors. These may be found on the circuit
breaker compartment door or in the low voltage
wiring compartment.
• Step 2/6
Remove the circuit breaker out of the
switchgear frame.
• Step 3/6:
Warning:
Check and ensure the equipment is
de-energized.
• Step 4/6
In the cable compartment, connect the injection
test set to the cable sealing end and the circuit
breaker compartment to the branch conductor
behind the lower shutter of the same phase.
• Step 5/6
Inject current equal to the Application nominal
current or equal to the maximal current
supported by the primary testing device if the
application nominal current is out of the device
setting range.
• Step 6/6
Check current metering for the phase and the
measured current in other phases on the
protection relay LHMI Measurements view.
Current must be zero in all phases which are not
under the primary injection test.
Notice:
“Io-A” in Measurements
view is a measured value, not a
calculated one.
On the protection relay LHMI go to
-> Main Menu/
Configuration/Analog inputs/
Current (3I, CT)
• Primary current = Application nominal current
• Amplitude Corr A = sensor rating plate, phase A
• Amplitude Corr B = sensor rating plate, phase B
• Amplitude Corr C = sensor rating plate, phase C
• Nominal current = Primary current
• Rated secondary Val = Rated secondary value in
mV/Hz
• Angle Corr A = sensor rating plate phase A
• Angle Corr B = sensor rating plate phase B
• Angle Corr C = sensor rating plate, phase C
—
32
—
33
—
35
—
34
—
32 Example of a
current sensor label
—
33 Current sensor
parameters
—
34 Test setup for
current sensors testing
when busbars are not
installed or there is
restricted access to the
busbar compartment
—
35 Measurements view
WARNING
NOTICE
L1
L2
L3
No
circuit
breaker
0V
0V
0V
I
I
Primary
tester
~I (A)
I
I
