Megger SR-98, Instruction Manual

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17
DIRECTIONAL RELAY Test Screen:
The DIRECTIONAL RELAY Test Screen is used to test all single-phase directional
elements in directional overcurrent and ground overcurrent relays. Many of the same
measured values seen in the OVERCURRENT RELAY Test Screen are in the
DIRECTIONAL RELAY Test Screen (see descriptions in the OVERCURRENT RELAY
Test Screen). The difference is the displayed phase angle,
φ
I lags V
, (current lags the
voltage), which is used in testing the sensitivity setting of the directional element.
The phase angle display is the measured phase angle between the
AC CURRENT
MAIN
output and the
AC AUX
Output. It displays
Current lagging Voltage
. Since
some directional elements are tested with current leading the voltage, simply subtract
the angle indicated from 360 to get the appropriate leading angle. For example, if the
test is to be conducted at 30 degrees current leading voltage, set the phase angle to
330 degrees (330 current lags voltage equals 30 degrees current leads voltage).
DC RELAY Test Screen:
The DC RELAY Test Screen is used to test all dc voltage auxiliary and dc current
relays.
The
DC SOURCE SELECT provides selection of the DC AUX output to provide either a
DC Voltage or a DC Current.