Updated: Apr 11, 2021
Protective relay is a device which maintains the power system equipments and gives an output under an abnormal condition to ensure protection of the system. ... During testing, protective relay is made to undergo simulated field conditions to check its performance.
In below article we will be discussion the testing of Synchronising Relay - MX3EGIA using K68i .
1. Synchronizer Relay
2. Relay Test Kit K68i
3. Single‐phase 220V,15A AC Power Supply*
4. Potential Earth Conductor.
*No Welding load shall be connected from the same circuit.
Step 1: Connect the power supply to the Relay Test Kit K68i.
Please ensure proper Earthing of Relay Test Kit by the Green color of Earthing
Indicator on the bottom right side of the main display. If the color of the earthing
indicator is Red then user has to ensure the integrity of power supply earthing.
Step 2: Make proper connections of MX3EG1A Relay and Relay Test Kit K68i as
per shown diagram below:
Step 3: Switch ON the Relay test kit K68i using “Power on Switch” button and go
to “AC Test Module”. Select any two Voltage Sources among Ua, Ub, Uc.
Step 4: Consider one voltage source as a Generator Voltage Signal and other as a
Bus Voltage Signal. Then vary parameters (Magnitude, Frequency & Phase)
according to the requirement.
# For Instance, we need to compare the Bar Frequency(fb) with Rated
Frequency(fn). Then Select the “Frequency” as a function. If fn=50Hz
and fb=52Hz, then take the Ua as a Rated frequency signal and Ub as
a Bar frequency signal.
# Point to be Noted: At a time, one Voltage signal must remain
constant in terms of parameters (Voltage, frequency, phase) .
Here, we take Ua as constant signal as it is a rated frequency signal and Ub
as a variable signal. By Variable, we mean that the signal is being ramped.
Step 5: For ramping a signal, Tick the check box ✔ front of the Ua, Ub.
# Ramping can be done by both: Manual as well as Auto Mode. The
mode is selected by clicking the Auto/Manual tab key from the front
panel of Relay Test Kit K68i.
# For Manual Mode: Set Step Size(Hz) and Deglitch Time(ms)
# For Auto Mode: Set Step(s) , Mode and Deglitch Time(ms)
Step 6: Press “Run” after setting all values. Synchronizer relay will actuate as per
the set parameters and accordingly gives a binary output to the Relay Test Kit
This binary output cable from Synchronizer relay is being connected to
the binary input ports of Relay Test Kit K68i. The binary output
command can be seen via LEDs on the Relay Test Kit Display.
Results can be seen in terms of tripping time on the Test kit display
under Result Index. The report is shown on the display of Relay Test Kit
K68i. The reports can be saved by pressing “Save” tab key on the front display
of Relay Test Kit K68i and same can be downloaded via USB/VGA
Port(on the top of Relay Test Kit K68i) for documentation and data
analysis. You can save data up to 1GB.
Step 7: For testing the variations of other remaining parameters of Synchronizer
Relay, please follow the above‐mentioned steps.