Atec Megger-MPRT8445 - Manual (Page 3)

MPRT
Megger Protective Relay Test System
3
As shown in the Overcurrent Settings screen, the IEEE Very
Inverse time curve was selected. If the Test Multiple is
changed, the appropriate theoretical trip time will change
automatically.
The TVI also has the ability to do even more complex tests
and calculations. For example, the MPRT with three
Voltage/Current Modules, can test single-phase, three-phase
open delta, and three-phase wye impedance relays using
the Impedance relay test screen. The user simply selects
different testing applications from a menu screen. For
instance, the Reach Test Settings Screen for an impedance
relay has been selected as shown below.
Impedance Reach Test Settings Screen
It should be noted that not only does the display screen
show values of voltage, current and phase angle, but it
also displays the current value where the relay should pick
up, (different formulas for calculating OHMS are selectable
using the touch-screen to select phase to phase or phase
to ground faults). The user can select ramp current and
hold fault voltage on ramp voltage and hold fault current.
The impedance test screen provides a pre-fault condition
for those relays that require a pre-fault load prior to
applying the fault. The test automatically determines values
like reach, maximum angle of torque, and timing.
Finally, for testing multi-zone relays, the user can select
the Pulse-Ramp method to determine operating points
without needing to defeat the other zone timers. Test
results can be saved to the internal memory for later
download and review.
Also easily test relays not on the Preset Menu
Other types of relays or devices not specifically listed in
the Preset Menu Screen can be tested using one of the
Manual Test screens.
Manual Voltage/Current Test Screen
For example, negative sequence under/over voltage,
reverse phase, phase sequence, and current balance relays
may be tested using the Voltage/Current manual test screen.
In addition, manual control of up to four voltages and
currents, or up to 8 currents is done using this test screen.
Other devices such as auto-synchronizing, frequency
sensitive devices and transducers also have their own
individual manual test screens. The user manually selects
the parameter(s) to be set or adjusted using the touch-
screen and ramp outputs using the control knob. Each test
screen has a dynamic enable capability and will either
automatically step from a prefault, to fault, to breaker trip,
to reclose, or automatically ramp frequency at a
preprogrammed Hz/Sec, or time for a given slip frequency,
depending on which screen is in use. In the Manual Auto-
Synchronizing Test Screen, the advanced closing time and
closing angle are automatically done in the dynamic mode.
In the Manual Test Screen shown above, the pre-selected
outputs are set. The Green color indicates which output(s)
have been selected. When the test is started by pressing
the Start button, the selected output indicators will change
colors from green to red indicating which outputs are
energized. A vector graph indicates the relative phase
angles of all of the outputs. All of the outputs are metered
and displayed to provide real time verification of all of the
selected outputs.
Even perform manual transducer testing
With the built-in transducer test screen, manually testing
transducers has never been easier. The user simply selects
from a pull-down menu, what type of transducer is being
tested and enters information relative to the transducer’s
inputs and outputs. Upon starting the test, the test set
automatically measures and calculates the % error of the
device.